2015 REPORT. Prepared for: City of Santa Barbara, Creeks Division. County of Santa Barbara, Project Clean Water. Prepared By:

Transcription

1 SOUTHERN COASTAL SANTA BARBARA STREAMS AND ESTUARIES BIOASSESSMENT PROGRAM 2015 REPORT Prepared for: City of Santa Barbara, Creeks Division County of Santa Barbara, Project Clean Water Prepared By:

2 Executive Summary Introduction This report summarizes the results of the 2015 Southern Coastal Santa Barbara Streams and Estuaries Bioassessment Program, an effort funded by the City of Santa Barbara and County of Santa Barbara. This is the 16 th year of the Program, which began in Ecology Consultants, Inc. (Ecology) prepared this report, and serves as the City and County s consultant for the Program. The purpose of the Program is to assess and monitor the biological integrity of study streams and estuaries as they respond through time to natural and human influences. The Program involves annual collection and analyses of benthic macroinvertebrate (BMI) samples and other pertinent physiochemical and biological data at study streams and estuaries using U.S. Environmental Protection Agency (USEPA) endorsed rapid bioassessment methodology. BMI samples are analyzed in the laboratory to determine BMI abundance, composition, and diversity. Study sites have included the range available along a disturbance gradient, from reference sites that are fairly intact in form with little urbanization in their watersheds to highly disturbed sites that have been substantially altered in form and drain highly urbanized watersheds. Intermediate moderately disturbed sites have also been surveyed. Local streams have been studied since 2000, and a BMI based Index of Biological Integrity (IBI) was constructed by Ecology in 2004, and updated in 2009 and again last year. The IBI yields a numeric score and classifies the biological integrity of a given stream as Very Poor, Poor, Fair, Good, or Excellent based on the contents of the BMI sample collected from the stream. By condensing complex biological data into an easily understood score and classification of biological integrity, the IBI serves as an effective tool for the City and County in monitoring the condition of local streams, and evaluating the benefits or consequences of watershed management actions. Local estuaries have been studied since A major goal is to identify several reliable BMI indicator metrics that show significant differences trends along a disturbance gradient in local estuaries. Such indicator BMI metrics will be the foundation in developing a reliable IBI or similar tool for assessing the condition of local estuaries, which hopefully can be produced after another year or two of study. Study Area The study area encompasses approximately 80 km of the southern Santa Barbara County coast from the Rincon Creek watershed at the Santa Barbara/Ventura County line west to Jalama Creek just north of Point Conception. There are approximately 50 1 st to 5 th order coastal streams along this stretch of coast, all of which drain the southern face of the Santa Ynez Mountains. 51 different stream study reaches in 20 watersheds have been surveyed on one or more occasions during the 16 years of the Program, while 10 different estuaries have been studied once or more over the last 5 years. Results Over the past 16 years, the Program has provided a wealth of information regarding the physiochemical habitat conditions and biota (particularly the BMI community) of local streams, and the influences of natural physiochemical and climatic variability and human development. The following statements can be made based on the research completed thus far: Southern Coastal Santa Barbara Streams and Estuaries Bioassessment Program Page 2

3 Negative impacts of human land use on local stream communities (particularly BMIs) have been documented with highly significant statistical test results. Degradation of stream communities (e.g., lower IBI scores and loss of sensitive species), as well as physiochemical habitat conditions, has increased linearly with increased watershed development. Urban development has been shown to have greater impacts on stream communities than has agricultural development. The IBI is highly effective as an indicator of biological integrity, with highly significant relationships with indicies of human disturbance. The IBI has properly differentiated between REF, MOD DIST, and HIGH DIST with a high degree of accuracy and consistency. Major episodic disturbances including extreme stream flows, drought conditions, and wildfires have been definitively shown to negatively impact stream communities, as evidenced by lower IBI scores and loss or significant reduction of sensitive BMI and vertebrate taxa following such events. In recent years, BMI communities have progressively declined at several sites in response to prolonged drought and resulting loss of flow and low dissolved oxygen levels. Local stream BMI communities have proven to be resilient, typically showing dramatic recovery from extreme episodic disturbances in a year or two. However, some of the more sensitive species (e.g., rainbow trout) have yet to return to streams impacted by wildfires, drought, and/or floods, and may require many years to recover. Stream habitat restoration sites M2 and AB5 have shown improved habitat conditions, but significant improvements in the BMI community have not occurred thus far. Channel and riparian restoration at these sites did not address larger scale impairments in hydrology, geomorphology, water quality, habitat continuity and connectivity that have resulted from alteration of their respective watersheds. Whether or not current and future restoration efforts will improve the BMI community at M2 and AB5 can only be evaluated via continued monitoring through time. The Program effort to study local estuaries is still new relative to our study of streams. Based on the limited data set available for estuaries, the following can be stated thus far: Determining the impacts of human land use on the BMI communities in local estuaries has proven to be more difficult compared with streams. One reason for this is the fact that there are fewer estuaries in the study area compared with streams, particularly in the REF category (i.e., only Gaviota and Jalama studied thus far). Also, wide salinity fluctuations make estuaries harsh environments where a relatively small number of BMI taxa can survive when compared with streams. Taxa richness has not proven to be a reliable indicator of estuary condition as it has in streams. We have identified several taxa that are more abundant in the REF estuaries, which are the basis of the metric % sens BMIs. This and possibly other metrics may be utilized to develop and IBI or similar assessment tool for local estuaries. More replication and diversification of REF estuaries having greater physiochemical variability will be needed to gain more confidence in our ability to understand the influences of salinity and other physiochemical parameters on indicator BMI metrics. Southern Coastal Santa Barbara Streams and Estuaries Bioassessment Program Page 3

4 TABLE OF CONTENTS Page I. INTRODUCTION... 6 II. STUDY AREA III. METHODS A. Field Surveys B. Laboratory Analysis C. GIS Analyses D. Review of Topographic Maps and Aerial Photographs E. Study Reach Grouping F. Calculation of Core Metrics for Streams G. Core Metric Scoring Ranges for Streams H. IBI Classifications of Biological Integrity and Scoring Ranges for Streams I. Data Analyses for Streams J. Calculation of BMI Metrics for Estuaries K. Evaluating Estuary BMI Taxa and Metrics for Disturbance Sensitivity L. Evaluating Salinity Effects on Estuary BMI Taxa and Metrics IV. RESULTS AND DISCUSSION A. Physiochemical and Biological Data B. Streams C. Estuaries V. CLOSING VI. ACKNOWLEDGEMENTS VI. REFERENCES APPENDIX: DATA TABLES AND ESTUARY HABITAT ASSESSMENT SCORING SHEET PLATES Page Plate 1 Reference Stream Reach Example... 9 Plate 2 Disturbed Stream Reach Example FIGURES Page Figure 1 Study Area Figure 2 Gaviota Coast Study Reaches Figure 3 Santa Barbara and Goleta Area Study Reaches Figure 4 Carpinteria Area Study Reaches Figure 5 Carpinteria Creek Watershed IBI Scores Figure 6 Sycamore Creek Watershed IBI Scores Figure 7 Mission Creek Watershed IBI Scores Figure 8 Arroyo Burro Creek Watershed IBI Scores Figure 9 San Jose Creek Watershed IBI Scores Southern Coastal Santa Barbara Streams and Estuaries Bioassessment Program Page 4

5 Figure 10 Arroyo Hondo Creek Watershed IBI Scores Figure 11 Gaviota Creek Watershed IBI Scores Figure 12 ANOVAs of IBI Score for F-F, F-P, and P-P Flow Groups Figure 13 ANOVAs of IBI Score for REF Reaches by Year Figure 14 ANOVAs of IBI Score for HIGH DIST, MOD DIST, and REF Groups for Selected Years Figure 15 ANOVAs of Mean Abundance of Selected BMI Taxa in Estuaries Figure 16 ANOVAs of % Sensitive BMIs and % Tolerant BMIs in Estuaries Figure 17 Linear Regression of % Sensitive BMIs vs. Salinity, REF Group TABLES Page Table 1 Study Reaches Table 2 Core Metric Scoring Ranges Table 3 IBI Classifications of Biological Integrity Table 4 BMI Metrics Calculated for Study Estuaries Southern Coastal Santa Barbara Streams and Estuaries Bioassessment Program Page 5

6 I. Introduction This report summarizes the results of the 2015 Southern Coastal Santa Barbara Streams and Estuaries Bioassessment Program, an effort funded by the City of Santa Barbara and County of Santa Barbara. This is the 16 th year of the Program, which began in Ecology Consultants, Inc. (Ecology) prepared this report, and serves as the City and County s consultant for the Program. The purpose of the Program is to assess and monitor the biological integrity of study streams and estuaries as they respond through time to natural and human influences. The Program involves annual collection and analyses of benthic macroinvertebrates (BMIs) and other pertinent physiochemical and biological data at study streams and estuaries using United States Environmental Protection Agency (USEPA) endorsed rapid bioassessment methodology. BMIs are aquatic insects, crustaceans, mollusks, worms, and other invertebrates of a halfmillimeter in length or greater that inhabit the bottom substrata of streams, lakes, ponds, estuaries, ocean waters, and other water bodies for at least part of their life cycles. BMI samples are analyzed in the laboratory to determine BMI abundance, composition, and diversity. Scores and classifications of biological integrity are determined for study streams using the BMI based Index of Biological Integrity (IBI) constructed by Ecology. The IBI was initially built in 2004, updated in 2009, and updated again last year in What is biological integrity? Biological integrity can be defined as the ability (of a water body) to support and maintain a balanced, integrated, adaptive community of organisms having a species composition, diversity, and functional organization comparable to that of natural habitat of the region. (Miller et al., 1988). In other words, biological integrity can be thought of as the overall biological condition of a water body in comparison to natural, more or less pristine habitat in the same region. Natural perturbations such as heavy floods, droughts, and wildfires, as well as human disturbances (e.g., to hydrology, geomorphology, water chemistry, etc.) have been shown to negatively impact the biological integrity of waters locally and around the world. How do we determine, or measure, biological integrity? Bioassessment is the science of determining, or measuring, the biological integrity of water bodies by evaluating the composition of the biological communities that inhabit them. The origins of bioassessment in the United States and Europe date back to the late 1800 s. Within the last 30 years, the incorporation of bioassessment into water monitoring programs has increased dramatically throughout the United States because of the development of rapid, costeffective assessment and data analysis techniques (Rosenberg and Resh, 1993). Currently, bioassessment is used throughout the U.S. and the world to assess, monitor, and manage the integrity of streams, rivers, lakes, ponds, estuaries, and coastal marine waters. The foundation of bioassessment is the fact that individual aquatic species have varying habitat requirements and abilities to withstand natural and human disturbances. Thus, the composition of the biological community, or the species present and their relative abundances, provides a valuable indication of biological integrity. The disturbance sensitivity of each unique species depends on their physiology, size, habitat requirements, survival strategy (i.e., primary producer, filter feeder, grazer, predator, etc.), and of course the nature of the disturbance(s). Southern Coastal Santa Barbara Streams and Estuaries Bioassessment Program Page 6

7 As an example, the presence of viable salmonid populations in coastal California streams generally indicates good biological integrity. To thrive, salmonids require cool, clean, well-oxygenated stream water, clean cobble/gravel beds for spawning, deep pools for cover from predators, and an adequate aquatic invertebrate and vertebrate prey base. Salmonids are especially sensitive to increased fine sediment loads, higher stream temperatures, low dissolved oxygen levels, water pollutants, and other habitat modifications such as the construction of dams and other migration barriers that typically occur in areas with intensive human development. While species such as salmonids that are sensitive to habitat disturbances are typically reduced or eliminated in highly disturbed water bodies, disturbance Rainbow trout in Rattlesnake Creek tolerant species may persist or even flourish. Disturbed waters typically have a biological community composed of a smaller number of more disturbance tolerant taxa compared to more natural, pristine waters, which typically have higher numbers of taxa, including those that are disturbance sensitive. Beyond individual species, measurements of the biological community, or biological metrics, relating to abundance, species richness, proportion of disturbance sensitive species, and trophic structure have been shown to be reliable indicators of biological integrity in hundreds of bioassessment studies around the world. The reliability of such metrics as indicators of biological integrity depends on the strength of their relationships with measures of habitat disturbance. How does human development impact habitat conditions in local streams and estuaries? The study area encompasses the southern slopes of the Santa Ynez mountains from the Santa Barbara/Ventura County line to Point Conception. In general, human development is minimal in the northern mountainous areas, with some grazing, orchards and light residential uses in the foothills, transitioning to more intensive agriculture and urban development further southward where there are extensive coastal plains. The majority of development is concentrated in the cities of Santa Barbara, Goleta, and Carpinteria. Disturbance is limited mostly to orchards, grazing, and rural residential uses west of Goleta to Point Conception. View to south from East Camino Cielo above Rattlesnake Canyon (Mission Creek drainage) Generally, the nature and magnitude of disturbance in local streams and estuaries is proportional to the cumulative intensity and extent of development in their watersheds. Plates Southern Coastal Santa Barbara Streams and Estuaries Bioassessment Program Page 7

8 1 and 2 provide examples of two stream study reaches: (1) a relatively pristine stream in the undeveloped mountains, and (2) a disturbed stream on the urbanized coastal plain. The plates show the positions of these two stream reaches in their respective watersheds, surrounding land uses, and photographs of stream habitat conditions and aquatic species. Common forms of human disturbance in local streams and estuaries include: (1) altered hydrology and geomorphology due to water diversions, urban and agricultural land development, and flood control projects; (2) burying of stream and estuary substrate due to increased deposition of fine sediments from eroding agricultural fields and stream banks; (3) loss of riparian and upland habitat essential to many aquatic species; (4) loss of stream and estuary habitat complexity, algal blooms, elevated water temperatures, wider fluctuations in dissolved oxygen, and loss of energy inputs due stream channelization and removal of riparian vegetation; (5) degraded water quality due to inputs of fertilizers, pesticides, petroleum hydrocarbons, heavy metals, and other pollutants; (6) habitat fragmentation and barriers to species movement and migration due to the construction of in-stream barriers such as dams, road crossings, bridges, and culverts; (7) introductions of invasive, non-native plants and animals, which can outcompete and threaten the long-term viability of native species; and (8) disturbances to vegetation and/or wildlife associated with trampling, noise, lighting, air pollution, and predation by domestic pets. What is the streams IBI? What does it tell us? The streams IBI developed for this Program is a multimetric tool that provides a standardized, integrative, and readily understandable scale for measuring the biological integrity of local streams. Because biological assemblages vary in response to natural physical and chemical gradients that occur through geographic space, IBIs are calculated for specific regions and water body types (i.e., streams, lakes, estuaries, etc.) with similar ecological characteristics. The term multimetric refers to an IBI being constructed by combining several individual biological metrics into a single index. Our IBI uses 7 BMI metrics derived from the BMI samples collected at the study stream reaches. These core metrics are all highly sensitive to human disturbance as determined through rigorous statistical analyses, and collectively represent several aspects of BMI community structure including relative abundances of disturbance sensitive and tolerant taxa, taxonomic richness, and trophic structure. Values for each core metric at a study stream are scored on a dimensionless numeric scale (e.g., from 0 to 10) relative to the known distribution of values for sites BMI sampling in Gobernador Creek along a human disturbance gradient. Higher scores (e.g., a 10) represent the conditions at the most pristine sites, whereas lower scores indicate greater departure from pristine conditions. Scores assigned to the individual core metrics are equally weighted and combined into an overall score. The IBI classifies the biological integrity of a given stream as Very Poor, Poor, Fair, Good, or Excellent based on the overall score. The IBI serves as an effective tool for the City and County in monitoring the condition of local streams, devising and prioritizing watershed management actions, and evaluating their benefits or consequences. Southern Coastal Santa Barbara Streams and Estuaries Bioassessment Program Page 8

9 Plate 1: Reference Stream Reach Example Stream reach location marked on map (left) by black dot. Upstream watershed drains wilderness lands (olive green and brown in map). Downstream agricultural (light green) and urban (grey) lands (downstream) do not affect this stream reach. Stream has unaltered hydrology and form, with natural bed and banks, alternating riffles and pools, boulder and cobble beds (no excessive fine sediments), and intact mostly native riparian vegetation with mature canopy trees. Stream habitat is optimal for a variety of aquatic and riparian species, including a diverse BMI community and several sensitive aquatic vertebrates including rainbow/steelhead trout, California newt, and southwestern pond turtle (below). Southern Coastal Santa Barbara Streams and Estuaries Bioassessment Program Page 9

10 Plate 2: Disturbed Stream Reach Example Stream reach location marked on map (left) by black dot. Stream drains urban (grey), agricultural (light green) and wilderness lands (olive green/brown). Impervious surfaces (urban), channelization, and increased fine sediment loads (agriculture) have altered stream hydrology and form, and water pollutants (e.g., nutrients, pesticides, hydrocarbons) are present. Stream banks have been largely denuded of native vegetation, resulting in unstable, eroding banks, establishment of invasive non-native plants (e.g., Arundo donax below), algal blooms, and wide fluctuations in water temperature and dissolved oxygen. Fine sediments largely smother boulder, cobble, and gravel that would provide stable aquatic habitat. Sensitive BMIs and aquatic vertebrates are largely absent due to habitat degradation. Southern Coastal Santa Barbara Streams and Estuaries Bioassessment Program Page 10

11 Why use BMIs? There are several reasons why BMIs are useful as biological indicators. First, BMIs are a critical component of aquatic ecosystems, often representing a large proportion of community biomass, performing important functions in the cycling of nutrients and energy, and constituting food sources for vertebrate predators such as fish and amphibians. Major changes in BMI assemblages can have profound ramifications for aquatic ecosystems. Secondly, the responsiveness of BMIs to environmental perturbations, including human impacts, is well documented. Information is available on the life histories, distributions, habitat requirements, and disturbance tolerances of most BMIs. In the case of local streams, BMIs also are far more abundant and diverse compared to aquatic vertebrates (e.g., fish and amphibians), and are relatively easy to collect. Estuaries In 2011 the Program was expanded to include estuaries. Estuaries are open water bodies where a freshwater stream meets and mixes with saltwater from the ocean, creating brackish water conditions with salinities that vary depending on fluctuating seasonal inputs from the stream and ocean. USEPA endorsed rapid bioassessment methods for estuaries have been used to collect BMI samples and other pertinent physiochemical and biological data in local estuaries. Over the past 5 years a data set has been compiled for local estuaries. Study sites have included the range available along a disturbance gradient, from reference sites that are fairly intact in form with little urbanization in their watersheds to highly disturbed sites that have been substantially altered in form and drain highly urbanized watersheds. Intermediate moderately disturbed sites have also been surveyed. A total of 9 estuaries were studied this year. A goal in studying local estuaries is to identify reliable BMI indicator metrics that show significant trends along a disturbance gradient. Hopefully, such indicator BMI metrics will be the foundation in developing an IBI or similar tool for local estuaries within the next year or two. Stoneflies and Hemiptera in Gobernador Creek Jalama Creek estuary (low disturbance) Mission Creek estuary (high disturbance) Southern Coastal Santa Barbara Streams and Estuaries Bioassessment Program Page 11

12 II. Study Area The study area encompasses approximately 80 km of the southern Santa Barbara County coast from the Rincon Creek watershed at the Santa Barbara/Ventura County line west to the Jalama Creek watershed, which is just north of Point Conception (see Figure 1). There are approximately 50 1 st to 5 th order coastal streams along this stretch of coast, all of which drain the southern face of the Santa Ynez Mountains. 52 different stream study reaches in 20 watersheds have been surveyed on one or more times during the 16 years of the Program, while 10 different estuaries have been studied one or more times over the last 5 years. Figure 1 shows an overall map of the study area, and Figures 2, 3, and 4 provide more detailed maps and show the locations of the stream and estuary study reaches that have been surveyed over the years (except the Jalama Creek estuary). This year, 16 stream reaches and 9 estuaries were surveyed (see Table 1). Table 1: 2015 Study Reaches Study Reach Location C1 Carpinteria Creek, 0.25 mi. downstream of Carpinteria Ave. C3 Gobernador Creek, approx mi. upstream of County detention basin SY2 Sycamore Creek 1,000 below Hwy. 192 crossing and Coyote/Sycamore confluence M1 Mission Creek just downstream of De la Guerra St. M2 Old Mission Creek at Bohnet Park M3 Mission Creek at upstream end of Rocky Nook Park M4 Rattlesnake Creek, approx. 0.5 mi. upstream of Las Canovas Rd. crossing AB1 Arroyo Burro at upstream end of Alan Rd. AB5 Mesa Creek just upstream of entrance to Arroyo Burro estuary AB7 Las Positas Creek just above Veronica Springs Rd. crossing AB8 Las Positas Creek 0.25 mi. upstream of AB7 SJ2 San Jose Creek approx mile upstream of Patterson Rd. crossing AH0 Arroyo Hondo just upstream of U.S AH1 Arroyo Hondo, approx. 1 mi. upstream of U.S GAV1 Gaviota Creek at State Beach/Park just upstream of access road crossing LC1 Las Canovas Creek just upstream of confluence with Gaviota Creek Estuary Study Reaches Ce Carpinteria Creek estuary SYe Sycamore Creek estuary Me Mission Creek estuary ABe Arroyo Burro estuary GOLe Goleta Slough estuary Be Bell Canyon estuary Te Tecolote Creek estuary GAVe Gaviota Creek estuary Je Jalama Creek estuary Southern Coastal Santa Barbara Streams and Estuaries Bioassessment Program Page 12

13 FIGURE 1: STUDY AREA Study Area N Source: Delorme Topoquads Southern Coastal Santa Barbara Streams and Estuaries Bioassessment Program Page 13

14 FIGURE 2: GAVIOTA COAST STUDY REACHES N GAV2 LC1 Gaviota Creek GAV1 GAVe SO2 San SO2 Onofre Creek San Onofre Creek SO1 AH1 AH0 AH2 Arroyo Hondo Arroyo Hondo Creek R0 R2 R1 Refugio Creek R2 Refugio Creek R1 El Capitan Creek EC1 EC1 Scale: 1 centimeter = 1 kilometer Source: Delorme Topoquads (1999) Study creeks emphasized for ease of recognition Southern Coastal Santa Barbara Streams and Estuaries Bioassessment Program Page 14

15 FIGURE 3: SANTA BARBARA AND GOLETA AREA STUDY REACHES Dos Pueblos Creek DP1 N Te Tecolote Creek T3 T2 T1 Be San Jose Creek SJ2 SJ1 GOLe SJ4 SJ3 AT1 Scale: 1 centimeter = 1.5 kilometers Source: Delorme Topoquads (1999) MY1 Maria Ygnacio Creek MY2 MY3 SA1 San Antonio Creek SA2 Atascadero AB6 Creek Arroyo AT2 Burro AB2 AB1 ABe AB3 AB4 AB7 AB8 M2 M3 M6 Mission Creek AB5 M1 M4 M5 SY2 Sycamore Creek Me SY1 SYe Southern Coastal Santa Barbara Streams and Estuaries Bioassessment Program Page 15

16 FIGURE 4: CARPINTERIA AREA STUDY REACHES Arroyo Paredon Creek Santa Monica Creek Franklin C3 Rincon AP1 Creek Carpinteria Creek F1 Creek RIN1 SM1 C2 Ce C1 RIN0 N Scale: 1 centimeter = 2 kilometers Source: Delorme Topoquads (1999) Study streams emphasized for ease of recognition Southern Coastal Santa Barbara Streams and Estuaries Bioassessment Program Page 16

17 III. Methods Physiochemical and biological data for the stream and estuary study reaches was gathered through a combination of methods including field surveys, laboratory analyses, spatial data analyses using geographic information system (GIS) software, and review of United States Geological Survey (USGS) 7.5-minute quadrangle maps and recent aerial photographs. BMI parameters were calculated from the raw data. Statistical tests including linear regressions and analyses of variance (ANOVA) were used to evaluate the streams and estuaries data for relationships with physiochemical parameters and measures of human disturbance. Further discussion of methods is provided below. A. Field Surveys 1. Streams Stream surveys involve annual collection of BMI samples and other pertinent physiochemical and biological data at study streams and estuaries using USEPA endorsed rapid bioassessment methodology. Our sampling methodology has been consistent since 2000, and is very similar to that currently used for the California Surface Water Ambient Monitoring Program (SWAMP), the methods of which have varied over the years. As in previous years of the Program, field surveys were conducted in the spring during base stream flow conditions (i.e., low flows). The sampling was conducted in May. Sampling in the spring during base flow conditions provides consistency in the sampling from year to year, as the local stream biota is known to undergo seasonal succession (Cooper et al., 1986). The following was completed during each field survey: General observations were recorded on a standardized field data sheet, including location, date, time, weather, stream flow conditions, water clarity, and human impacts. A 100-meter study reach was delineated along the stream. Stream habitat units (i.e., riffles, runs, pools, etc.) within the study reach were mapped and quantified as a percentage of the total reach length. Stream wetted and channel bottom width were measured at three transects in the study reach. The three transects were established at the 25, 50 and 75 meter marks. Wetted perimeter width is the cross-sectional distance of streambed that is inundated with surface water. Channel bottom width is the cross-sectional distance between the bottoms of the stream banks. Riparian canopy cover was estimated in the center of the stream channel at the three transects using a spherical densitometer. Plant and wildlife species observed in the stream and riparian zone were noted and recorded. Water temperature, conductance, ph, and dissolved oxygen concentration were measured in the field using YSI and Oakton handheld meters. Two measurements of each parameter were made, one in a riffle and the other in a pool, and the two values were averaged. Southern Coastal Santa Barbara Streams and Estuaries Bioassessment Program Page 17

18 One composite BMI sample was collected from each study reach using a standardized method based on the multi-habitat approach described in the USEPA s Rapid Bioassessment Protocols for Use in Streams and Wadeable Rivers (Barbour et al., 1999). Each sample represents approximately one square meter of stream bottom, collected from 10 individual, 0.1-square meter locations (an approximately 30 cm square). The 10 locations that constituted the sample were selected based on the relative area each stream habitat (i.e., riffles, pools, falls, etc.) covered in the section of stream sampled. For example, if a stream reach contained approximately 50 percent riffles and 50 percent pools, five locations in riffles and five in pools were selected and sampled. Samples were collected using a D-frame net with 500 µm mesh. In locations with flowing water (e.g., riffles and runs), the net was held upright against the stream bottom, and substrata immediately upstream within the 0.1-square meter area was scraped and stirred up for approximately 15 seconds using feet and hands. Dislodged BMIs and stream bottom materials were carried into the net by the stream current. In areas with little or no current (e.g., pools), stream bottom material was stirred up by foot, followed by a quick sweep of the net through the water column to capture dislodged BMIs. This was repeated three times in each pool sampling location. After each BMI sample was collected, it was rinsed with water in a 500 µm sieve to wash out fine sediments, transferred to a plastic container, and preserved in 70 percent ethanol. A stream habitat assessment was completed using a new protocol developed by Ecology. The new protocol is similar to the U.S. EPA method used in previous years, but the habitat components and scoring criteria have been revised based on our 15 years of experience studying local streams. The old U.S. EPA provided a good basis to begin from, but some categories were redundant, and scoring criteria in some cases did not apply well to local streams. The new protocol yields a total score from 0 to 100 points for each study stream based on the assessment stream path and form (0-20), habitat diversity (0-10), habitat connectivity (0-10), hydrology (0-10), water column depth/velocity/quality (0-10), substrate/erosion/sedimentation (0-10), riparian vegetation cover/composition (0-10), riparian/upland buffer (0-10), and foot traffic/noise/lighting (0-10). The new habitat assessment is provided in the Appendix. Quality control measures were incorporated into the field surveys to insure accurate and consistent data gathering. Water monitoring equipment was calibrated regularly. Field crew members were trained to properly operate equipment, take measurements, collect BMI samples, and conduct stream habitat assessments. 2. Estuaries Ecology conducted a rapid bioassessment survey in each study estuary in early October. Methodology was based on the Tier 1 approach described in Estuarine and Coastal Marine Waters: Bioassessment and Biocriteria Technical Guidance (Bowman et al., 2000). The Tier 1 approach is intended to provide an assessment of coastal wetland habitats based on sampling of one or more biological assemblages (e.g., algae, invertebrates, fish, etc.) and collecting data on water chemistry and bottom characteristics. The following was completed: Southern Coastal Santa Barbara Streams and Estuaries Bioassessment Program Page 18

19 General observations were recorded, including study reach location, date, time, weather, water clarity, sediment composition, vegetation, hydrologic condition (i.e., estuary open or closed to ocean), tide conditions, and sources of human disturbance. Measurements of water temperature, ph, dissolved oxygen concentration, conductance, and salinity were made. Measurements were made at the downstream end of the estuary. BMI samples were collected at the downstream end of the estuary. Two separate samples were collected at each monitoring station; (1) an infaunal sample consisting of approximately the top 15 cm of sediments from two approximately 10 cm diameter areas of the estuary bottom collected in 0.3 to 0.6 m of water using a core sampler, and (2) an epibenthic sample consisting of material collected in five sweeps with a D-net similar to the pool sampling method for streams (i.e., 0.1 m 2 per sweep). After collection, each sample was drained through a 0.5-millimeter mesh sieve to wash out fine sediments, and the remaining material was placed into a plastic bottle filled with 70% ethanol solution for preservation. In total, approximately 0.5 m 2 of bottom area was sampled at each monitoring station. Quality control measures were incorporated into the field surveys to insure accurate and consistent data gathering. Water monitoring equipment was calibrated regularly. Field crew members were trained to properly operate equipment, take measurements, and collect BMI samples. A quantitative habitat assessment was developed this year by Ecology and used to rate the habitat quality of each study estuary. Scoring was based on consideration of nine habitat components. Estuary form and perimeter was scored from 0 to 20, while a score from 0 to 10 was given for the other eight components: habitat diversity, connectivity, hydrology, substrate, water column, aquatic vegetation, riparian/upland buffer, and foot traffic/noise/lighting. Scores for each component were added for a total score of 0 to 100. Scoring criteria for each habitat component were carefully developed using our knowledge of local estuaries and the range of conditions present in the study area. Scoring for each estuary was based on field observations and measurements, and review of aerial photography. The estuary habitat assessment sheet is provided in the Appendix. B. Laboratory Analyses BMI samples were processed in the laboratory to determine BMI community composition (i.e., taxa present and relative abundance) and overall density. Each BMI sample was strained through a 500-µm mesh sieve and washed with water to remove ethanol and fine sediments. The sample was placed in a plastic tray marked with equally-sized squares in a grid pattern. The entire sample was spread out evenly across the squares. Squares of material were randomly selected, and sorted one at a time under a dissecting microscope (7X to 50X magnification) until the targeted number of BMIs were located and picked out. The proportion of the sample sorted was noted. For streams, 300 BMIs were picked from each sample for identification. A target of 150 BMIs was set for each estuary sampling site. The infaunal sample was sorted through first, and up to 75 BMIs were picked and identified. Next, the epibenthic sample was sorted, and the remaining number of BMIs were picked and identified to reach the target of 150. Southern Coastal Santa Barbara Streams and Estuaries Bioassessment Program Page 19

20 BMIs were identified with the aid of taxonomic references including Merritt and Cummings (2008) and Smith and Carlton (1975). Insect taxa were identified to the family level. Noninsect taxa (e.g., oligochaetes, crustaceans, etc.) were typically identified to order or class. After sorting and identification, BMIs were bottled in 70 percent ethanol for storage. BMI sample processing methods were clearly established and strictly followed to ensure random selection and accurate enumeration and identification of BMIs. C. GIS Analyses GIS Arcview software was used to calculate upstream watershed area and watershed land use covers for each study reach. Watershed areas were calculated based on watershed boundaries generated in Arcview. Watershed land uses and percent cover for each study reach were calculated by superimposing watershed boundaries over a digital land cover GIS layer for the region. The land cover layer was produced the California Department of Forestry and Fire Protection s (CDF) Fire and Resource Assessment Program (FRAP). The CDF land use map for the region showed coverage by the following eight land use categories: urban, agriculture, herbaceous, hardwood, shrub, conifer, water, and barren/other. Recent aerial photographs (2014 to 2015) of the region available on Google Earth were reviewed to refine the GIS land use layer. The parameter % watershed disturbed was calculated for each study reach by using the following equation: % watershed disturbed = % urban + % agriculture (% herbaceous) Herbaceous areas were counted as partially (i.e., a quarter) disturbed to reflect that much of the herbaceous lands in this region are used for livestock grazing or are previously cleared land. Such areas typically have lower habitat value and can contribute higher volumes of fine sediments to streams via erosion. D. Review of Topographic Maps USGS 7.5-minute quadrangle topographic maps (1:24,000 scale) for the study area were reviewed to determine stream order, elevation, and gradient for each study reach. Gradient was determined by dividing the elevation change between topographic contours immediately upstream and downstream of the study reach by the stream length between the contours. Stream length was determined by tracing a map wheel over the stream path. E. Study Reach Grouping Stream and estuary study reaches were placed into three different groups based on their level of human disturbance. These disturbance groups were assigned to study reaches a priori, or before the analyses of biological data, based on (1) physical habitat assessment scores, and (2) % upstream watershed disturbed. This approach allowed both reach and watershed scale impacts to be considered in the a priori assessment of habitat condition, both of which have been shown to be important predictors of BMI community composition in this and many other bioassessment studies. The following criteria are used to classify study reaches: REF = Reaches that are in a reference condition, or are minimally to lightly disturbed by human activities. Habitat assessment score is 75/100 or greater, and no Southern Coastal Santa Barbara Streams and Estuaries Bioassessment Program Page 20

21 more than 10 percent of the upstream watershed is developed through a combination of urban, agricultural and/or cleared herbaceous lands. MOD DIST = Reaches that are moderately disturbed by human activities. Habitat assessment score is 50/100 or greater, and between 10 to 40 percent of the upstream watershed is developed through a combination of urban, agricultural and/or cleared herbaceous lands. HIGH DIST= Reaches that are heavily disturbed by human activities. Habitat assessment score is less than 50 and/or greater than 40 percent of the upstream watershed is developed through a combination of urban, agricultural and/or cleared herbaceous lands. F. Calculation of Core Metrics for Streams The 7 core metrics were calculated for each stream study reach for use in determining IBI scores and classifications of biological integrity. The core metrics are among the most sensitive to human disturbance as determined by rigorous statistical analyses (, 2014). Collectively, the core metrics are diversified in that they represent different aspects of community structure including richness, disturbance sensitivity, and trophic structure. Each core metric and its method of calculation are discussed below. Number of Insect Families was determined by summing the number of insect families found in the sample. Number of EPT Families was determined by summing the number of families found in the sample from the insect orders Ephemeroptera (mayflies), Plecoptera (stoneflies), and Tricoptera (caddisflies), which as a group are generally sensitive to human disturbance. Percent PT was determined by summing individuals from the insect orders Plecoptera and Tricoptera, dividing by the total number of BMIs in the sample, and multiplying by 100. Tolerance value average, percent sensitive BMIs and percent tolerant BMIs were calculated using disturbance tolerance values for individual BMI taxa of between 0 and 10 based on their ability to withstand human disturbance. A tolerance value of 0 indicates that a BMI is extremely intolerant of human disturbance, with increasing scores indicating greater tolerances to human disturbance. Tolerance value average was determined by summing the tolerance values of all the individual BMIs in the sample, and dividing by the total number of BMIs in the sample. Percent sensitive BMIs was determined by summing the individuals with a tolerance value of 3 or less, dividing by the total number of BMIs in the sample, and multiplying by 100. Percent tolerant BMIs was determined by summing the individuals with a tolerance value of 7 or greater, dividing by the total number of BMIs in the sample, and multiplying by 100. Tolerance values and sensitivity designations for individual BMI taxa are provided in Table A-1 of Appendix A. Tolerance values have been assigned to most of the BMI taxa found in the study area based on statistical analyses of BMI data collected in study area streams from 2000 to 2014 (see the 2014 Report). These analyses evaluated abundance data for each taxa along a disturbance gradient. Tolerance values from List of Californian Macroinvertebrate Taxa and Southern Coastal Santa Barbara Streams and Estuaries Bioassessment Program Page 21

22 Standard Taxonomic Effort (California Department of Fish and Game, 2002) were used for taxa that did not occur in sufficient abundance in local streams to allow for meaningful statistical analyses. 8 taxa that occur in the study area did not meet abundance criteria established in the 2014 analyses, nor did they have tolerance values in List of Californian Macroinvertebrate Taxa and Standard Taxonomic Effort. Thus, no tolerance values are provided for these taxa. Percent predators + shredders was determined by summing individual BMIs with a predator or shedder functional feeding group designation, dividing by the total number of BMIs in the sample, and multiplying by 100. Functional feeding group designations were obtained from An Introduction to the Aquatic Insects of North America (Merritt and Cummins, 2008). G. Core Metric Scoring Ranges for Streams The IBI provides scoring ranges of between 0 and 10 for each of the seven core metrics (see Table 2). See the 2014 Report for discussion of how core metric scoring ranges were determined. For core metrics that decrease with increasing human disturbance (e.g., # insect families), higher values corresponded with higher scores. For core metrics that increase with increasing human disturbance (e.g., tolerance value average), lower values corresponded with higher scores. Table 2: Core Metric Scoring Ranges # EPT % sens # insect % shredders TV Avg. Score families BMIs families +predators %PT % tol BMIs to to , to to to to to to 25 16, 17 13, to , to to , 22 14, to to , to to , 20 12, 13 7 to 9 38 to , 8 17 to to , 18 10, 11 5, 6 43 to , 6 12 to to , 16 8, to to to , 14 6, to to to , 12 4, to to to 10 3, to , H. IBI Classifications of Biological Integrity and Scoring Ranges for Streams Individual scores for the 7 core metrics are summed to provide a total score of between 0 and 70 for the study reach. The IBI provides 5 classifications of biological integrity based on the total score: Excellent, Good, Fair, Poor, and Very Poor. IBI classifications and scoring ranges are provided in Table 3. See the 2014 report for discussion of how ranges were set for the 5 classifications of biological integrity. Southern Coastal Santa Barbara Streams and Estuaries Bioassessment Program Page 22

23 Table 3 IBI Classifications of Biological Integrity (Streams) Category Scoring Range Excellent 59 to 70 Good 46 to 58 Fair 29 to 45 Poor 11 to 28 Very Poor 0 to 10 I. Data Analyses for Streams Individual Streams Study Reaches A discussion of each stream study reach is provided, including physiochemical conditions, biological data, and IBI scores as determined through field surveys, lab work, and review of maps, aerial photos, and GIS. Study stream photographs are provided, as are graphs to illustrate IBI score trends through time. Drought Effects Analyses in previous years have shown significant negative effects to streams BMI communities and IBI scores following natural episodic disturbances including (1) very high rainfall and peak stream flows that occurred in winter 2004/2005, and (2) major wildfires including the Gaviota (2004), Gap (2008), Tea (2008), and Jesusita (2009) fires. In general, BMI communities recovered within a year or two following the extreme flows and fires. More recently (i.e., last year), negative effects to streams BMI communities and downward trends in IBI scores became evident in response to the current prolonged drought, which has reached 4 years in duration. While most of the stream study reaches have maintained perennial flow during drought periods that lasted a year or two, many have experienced partial or complete drying of riffles and even pools for substantial lengths of time over the past two years. Last year s analyses showed a downward trend in stream IBI scores in 2013, and even more so in 2014 in response to the ongoing drought. As the drought continued this year, it was anticipated that the downward trend on streams IBI scores would continue as well. Analyses of Variance (ANOVAs) were used to explore the nature and strength of relationships between stream flow at individual study reaches and IBI scores, core metrics, and other BMI parameters. Study reaches were partitioned into stream flow groups based on the following criteria: 1. (F-F): Flowing in spring, flowing the previous fall 2. (F-P): Flowing in spring, pools only or dry previous fall 3. (P-P): Pools only in spring, pools only or dry previous fall An ANOVA compares the means and distributions of a given metric among multiple sampling groups, and indicates the probability that the means for the groups are the same. The probability that the means are the same is expressed as p, which is between 0 and 1. The lower the p, the lower the probability that the group means are the same. A p of 0.05 (i.e., Southern Coastal Santa Barbara Streams and Estuaries Bioassessment Program Page 23

24 5%) or less is generally accepted as indicating a statistically significant difference between group means. Replicates for the ANOVAs included stream study reaches from 2012 to 2015, as we began making fall (late September or early October) observations of stream study reaches in ANOVAs were completed separately by disturbance group (i.e., REF, MOD DIST, and HIGH DIST) to account for the fact that human disturbance can greatly influence the BMI community, and was expected to mask any effects of drought at HIGH DIST and possibly at MOD DIST streams. Year-to-Year Trends in IBI Scores ANOVAs were completed to compare IBI scores for the 3 disturbance groups (REF, MOD DIST, and HIGH DIST) to see whether the IBI differentiated between disturbance groups this year and in the past. ANOVAs were also competed to compare IBI scores for REF study reaches for individual years from 2000 to J. Calculation of BMI Metrics for Estuaries 14 BMI metrics were calculated for the study estuaries, including measures of abundance, diversity, disturbance sensitivity, and trophic structure (see Table 2). Many of the metrics calculated are similar to some used effectively as indicators of biological condition in one or more recent estuarine studies conducted throughout the nation. Table 4: BMI Metrics Calculated for Study Estuaries BMI Metric Abbreviation Units of Method of Measurement Calculation BMI density None # per m 2 Lab # of taxa # taxa None Lab # of sensitive taxa # sens taxa None Lab # of tolerant taxa # tol taxa None Lab # sensitive taxa/# tolerant taxa # sens/ # tol None Lab % sensitive BMIs % sens BMIs % Lab % tolerant BMIs % tol BMIs % Lab % insects None % Lab % non-insects None % Lab % dominant taxon None % Lab % 2 dominant taxa None % Lab % predators % pred % Lab % collector-gatherers % cg % Lab 100+(%collector-gatherers %predators) 100+(%cg-%pred) % Lab BMI density (number of individuals per m 2 ) was calculated by dividing the number of specimens picked out of the sample by the subsampled area. Richness parameters were determined by counting the number of specified taxa identified in each sample. % sensitive BMIs, and % tolerant BMIs were calculated by adding the number of BMIs in the sample labeled as either sensitive or tolerant to human disturbance, dividing by the total number of individuals in the sample, and multiplying by 100. # sensitive taxa and # tolerant taxa were calculated by adding Southern Coastal Santa Barbara Streams and Estuaries Bioassessment Program Page 24

25 the number of taxa with these labels. Taxa have been labeled as being sensitive, moderate or tolerant to human disturbance using methods described below. Functional feeding group parameters (e.g., percent collector-gatherers, % predators) were determined using functional feeding group designations for individual taxa provided in Merritt and Cummins (2008). % dominant taxon and % 2 dominant taxa were determined as the percentage of the sample represented by the most common and two most common taxa, respectively. K. Evaluating Estuary BMI Taxa and Metrics for Disturbance Sensitivity ANOVAs were completed to compare mean abundances of individual BMI taxa among the REF, MOD DIST, and HIGH DIST groups. This was done to evaluate disturbance sensitivity of the individual taxa, and identify taxa that could be useful in developing BMI community metrics (i.e., % sensitive BMIs and % tolerant BMIs) that may serve as indicators of biological integrity. Individual taxa evaluated with ANOVA had a mean abundance of at least 0.5 individuals per site in at least one of the disturbance groups. Taxa with higher mean abundance at REF sites compared to HIGH DIST sites with significant or near significant results were labeled at sensitive. Taxa with higher mean abundance at HIGH DIST sites compared to REF sites with significant or near significant results were labeled as tolerant. Taxa that did not meet either of these criteria were considered to be moderately tolerant of human disturbance. ANOVAs were completed to compare mean values for the 14 BMI metrics (including % sensitive and % tolerant) among the REF, MOD DIST, and HIGH DIST groups to evaluate their disturbance sensitivity. BMI metrics with significant differences in means between REF and HIGH DIST groups were considered sensitive to human disturbance, and possible candidates as core metrics for a future estuarine IBI. L. Evaluating Salinity Effects on Estuary BMI Taxa and Metrics Linear regressions were completed to explore the natural relationships of salinity and select metrics in REF estuaries. A linear regression evaluates the relationship between an independent variable, or regressor (i.e., salinity), with that of a single dependent variable, or response variable (i.e., a BMI metric). A best-fit line is determined that represents the dependent variable as a function of the independent variable. The correlation coefficient (r 2 ) and p-value (p) are calculated in regression, and used to interpret the strength of the relationship between the response variable and the regressor. r 2 is given as a value between 0 and 1, and indicates the proportion of the variation in the response variable accounted for by its relationship with the independent variable. The higher the r 2, the better the fit of the line. P indicates the probability that the response variable and regressor are not related, and is given as a value of between 0 and 1. A p of 0.05 or less is generally accepted as indicating a statistically significant relationship between the regressor and response variable. REF estuaries only were used in these analyses to screen out potentially confounding influences of human disturbance. Understanding the influences of natural physiochemical variability will be an important part of the process of screening potential BMI indicator metrics. Based on the data collected thus far, salinity is the most important natural physiochemical factor affecting BMI composition in local estuaries. Other physiochemical parameters may be considered in the future as the REF sites data set grows. Southern Coastal Santa Barbara Streams and Estuaries Bioassessment Program Page 25

26 IV. Results and Discussion A. Physiochemical and Biological Data Table A-1 in the Appendix provides physiochemical data collected at the streams this year and in previous years of study. Table A-1 also lists BMI taxa and abundances for each stream studied, as well as BMI density, core metric values, and IBI score. Tolerance values and functional feeding groups are provided for individual BMI taxa. Table A-2 provides a list of the plant species observed at each stream, and the number and percentage of native vs. introduced plant species observed. Table A-3 provides a list of vertebrate species observed at the streams. For streams that have been surveyed multiple times, plant and vertebrate species observations are combined. Table A-4 provides physiochemical and BMI data and metrics for study estuaries. B. Streams 1. Stream Study Reaches The following discusses IBI scores at the individual streams for 2015, and compares this year s scores to previous years. Physical habitat conditions, rainfall and stream flow patterns, and other factors that have likely affected the stream biota are also discussed. Carpinteria Creek Watershed C1 is located in lower Carpinteria Creek just downstream of the 8th St. pedestrian bridge at an elevation of 15. Gradient is low at This is a MOD DIST reach, with 80% undisturbed, 17% agricultural, and 3% agricultural lands in its upstream watershed of 9,598 acres. Peak elevation in the Carpinteria Creek watershed is approximately 4,700. Habitat assessment score was 55 this year, and has ranged from 50 to 63 in 15 years of study. C1 is abutted by residential neighborhoods and vacant fields, and has natural soil banks with some loose riprap and old pipe and wire revetment present. The streambed is composed of small boulders, cobble, gravel, and sand, and normally has gentle riffles and deep pools. Flow was very low but continuous through C1, with slow narrow riffles, and pools that were showing signs of stagnation. The riparian corridor was in width, containing many mature cottonwoods and sycamores of 50 or more in height, and a generally dense understory. Due to a lack of scouring flows, emergent vegetation, primarily horsetails (Equisetum spp.) and watercress (Rorippa nasturtium-aquaticum), have established in much of the streambed. 63% of the 56 plant species recorded at C1 are native. Riparian canopy cover was 90%, and has ranged from 50 to 90%. Lower Carpinteria Creek is moderately fragmented from the upper mainstem and tributaries by partial barriers at C1 (above) and C3 (below): Low but continuous flow, natural boulder/cobble substrate, stream channel is thick with vegetation due to lack of scouring. Southern Coastal Santa Barbara Streams and Estuaries Bioassessment Program Page 26

27 U.S. 101 and other road crossings and debris basins. Noise, lighting, and human traffic impacts at C1 are moderate. C3 is in Gobernador Creek (Carpinteria Creek tributary) ¼-mile upstream of the debris basin at an elevation of 420. C3 is a REF study reach, with an upstream watershed of 4,517 acres of 100% undisturbed wilderness lands and peak elevation of approximately 4,700. Human disturbances upstream of C3 are limited to dirt roads and cattle ranching. In the past there was a 2 metal pipe running down the stream indicating a possible surface water diversion, but these were washed out. It is unknown if there are currently any major surface water withdrawals from the stream. This section of Gobernador Creek has moderate gradient (0.03) and passes through a narrow gorge. Canyon walls are composed of exposed bedrock and soil slopes, and the streambed is formed in the bedrock with large boulders, small boulders, cobble, gravel, and sand substrate. Riffles and cascades alternate with pools of varying sizes and depths of 1 to 4. Flow was low but continuous through C3 this year, and flow has typically been perennial over the years. Overall, stream habitat is excellent, as reflected by a habitat assessment score of 85 this year, ranging from 85 to 93 in 15 years of study. The riparian corridor is dense and dominated by mature white alders (Alnus rhombifolia), sycamores, and coast live oaks, with riparian canopy cover of 95% this year and range of % overall. While 83% of the 69 plant species recorded at C3 are native, approximately 30-40% of the riparian understory cover is non-native, mostly thoroughwort (Ageratina ademorpha) and cape ivy (Senecio mikanioides). Due to a lack of scouring flows, emergent vegetation, primarily horsetails and thoroughwort, were established in much of the streambed this spring. C1 had favorable water temperature (17.0 ºC), ph (7.6) and dissolved oxygen (6.7 mg/l), but elevated specific conductance (1,821 µs), likely indicating that there are pollution inputs (i.e., increased ionic dissolved solids) from agricultural and urban runoff. In the past specific conductance typically has been in the 1,200-1,800 µs range. C3 also had favorable water temperature (13.4 ºC), ph (7.9) and dissolved oxygen (8.2 mg/l). Specific conductance was much lower (1,120 µs) than at C1, yet the highest it has been in 15 years of study at C3, where it has typically been in the µs range. The previous high was 1,000 µs last year. The higher mineral content in the water is presumably a side effect of the prolonged drought, which has resulted less contribution of relatively diluted rainwater to surface flows, and concentration of dissolved minerals in the shallow groundwater deposits that feed surface flows in the dry season. IBI score at C1 was 5 (Very Poor), and within the range (0 to 19) from 15 years of study (see Figure 5). The consistently low IBI scores for C1 over the years are puzzling. This site has good substrate dominated by cobble, gravel, and sand, well-defined riffles and pools, natural banks and a decent riparian corridor with numerous mature canopy trees. The basic water quality parameters measured have shown signs of disturbance in the form of moderately high conductivity and somewhat variable dissolved oxygen, but not alarmingly so. The watershed has little urban use (3%), some agriculture (17%), and is mostly undisturbed wilderness (80%). Other sites such as SJ2, AB1, and SY2 with similar or greater habitat disturbances have consistently had higher IBI scores compared to C1. A likely contributor to low IBI scores at C1 is a lack of flowing water in the dry season in low rainfall years. This site has always been wet in fall observations, but last September (2014), while it had pools, there was no visible flow, and dissolved oxygen was very low at 2.0 mg/l. Similar conditions were observed in September Southern Coastal Santa Barbara Streams and Estuaries Bioassessment Program Page 27

28 2013 as well. Lack of flow and dissolved oxygen crashes in the dry season could be responsible for a loss of many BMI taxa in drought years. However, the BMI community at C1 has been depauparate as well following wet years when flow has been perennial, which would allow establishment of a more diverse BMI community in a healthier stream. More detailed analyses of the water chemistry at C1 and determination of upstream water pollutant sources may shed light on other causes of biological impairment at C1. IBI score was 14, Poor at C3 this year, the lowest in 15 years of study at this site (see Figure 5). IBI score was also Poor last year (24). C3 is a REF stream that typically scores in the Good to Excellent range. C3 had only standing pools in September 2013 and 2014, presumably with low dissolved oxygen levels. The past 2 years C3 has been characterized by much lower than normal EPT and insect family richness, and a higher proportion of tolerant BMIs, mostly Chironomidae, which made up over 60% of the sample this year. Similar patterns have been observed in other REF and MOD DIST stream reaches including M3, M4 and AB3 that dried in the dry season in drought years. IBI Score Figure 5: Carpinteria Creek Watershed IBI Scores Year C1 C3 30 vertebrate species have been observed over the years at C1, including 2 aquatic species: Pacific tree frogs (Psuedacris regilla) and three-spine sticklebacks (Gasterosteus acleatus). At C3, 37 vertebrate species have been observed, including 5 aquatic species: rainbow trout (Oncorhynchus mykiss) and California newts (Taricha torosa), both observed in large numbers in most years, and two-striped garter snake (Thamnophis hammondii), California tree frog (Pseudacris cadaverina), and Pacific tree frog. However, no trout have been observed at C3 the last 2 years, presumably due to drying over the last couple of summers due to the drought. Southern Coastal Santa Barbara Streams and Estuaries Bioassessment Program Page 28

29 Sycamore Creek Watershed SY1, located in lower Sycamore Creek just downstream of Mason St., was completely dry for the second straight year and therefore was not surveyed. SY2 is located in the foothills near the middle of the Sycamore Creek watershed at an elevation of 170 above sea level. Gradient is moderate at This is HIGH DIST reach due to its high level of watershed development, with 52% undisturbed, 46% urban, and 2% agricultural lands in its upstream watershed of 1,956 acres. Peak elevation in the Sycamore Creek watershed is approximately 2,100. Habitat assessment score was 65 this year, and has ranged from 55 to 68 in 12 years of study. Just above its banks SY2 is tightly abutted by Sycamore Cyn. Rd. on its east, and a steep slope planted with avocados to the west, with homes tightly abutting the stream upstream and downstream of SY2. Several driveways cross the stream upstream and downstream of SY2, the bridges having grade drops that act as significant movement barriers, fragmenting the stream habitat. The stream has mostly natural bedrock and boulder bed and banks, with steep riffles, cascades, falls, and pools. There is some riprap and asphalt debris in the stream channel. As in previous years, high levels of fine sediments were present, partially filling pools and moderately to highly embedding much of the riffle cobbles and gravels. Sources of fine sediments include erosional areas from large landslides in the upper canyons and middle reaches, particularly where Sycamore Creek and its tributaries cut through Monterey and Rincon shale formations. Past residential lot grading without proper erosion control measures in the upper watershed also contributes to erosion problems (Questa, 2005). Stream flow was very low but continuous throughout SY2 during this year s spring survey, showing the effects of the 4-year drought. Riffles were very shallow (1 or less deep) and narrow (less than 1 ) but were flowing. Pools were generally narrower and shallower compared to wetter years, ranging in depth from 0.5 to 2.0. The stream banks support a narrow corridor of mostly native riparian vegetation with a canopy dominated by mature sycamore (Plantanus racemosa), coast live oak (Quercus agrifolia), and willows (Salix spp.). Riparian canopy cover was 90%, and has ranged from 72 to 100% in previous years. Due to the absence of significant scouring flows, the stream channel has become choked with emergent herbaceous plants and riparian vines, mostly horsetail, Poison oak (Toxicodendron diversilobum), and California blackberry (Rubus urinus). 46% of the 41 plant species recorded at SY2 are native. Human impacts at the site include noise and lighting from the Sycamore Cyn. Rd. and nearby homes, and human traffic in the streambed and banks as evidenced by SY2: upstream view SY2: vegetated streambed SY2: Red-eared slider Southern Coastal Santa Barbara Streams and Estuaries Bioassessment Program Page 29

30 trampling of riparian vegetation and the presence of bottles and other trash. Water chemistry measurements at SY2 were typical of previous years, with low water temperature (14.6ºC), adequate dissolved oxygen (6.3 mg/l), and high specific conductance (2,282 µs). Over the years, Sycamore Creek study reaches have had consistently higher conductance compared study reaches in other nearby watersheds (e.g., Mission Creek, Arroyo Burro, Montecito Creek), with similar human development patterns. While high stream conductance is a common symptom of pollutant loading from human sources, it can also be due to naturally high mineral content in shallow groundwater, which varies considerably in mineral content locally due to influences of surrounding bedrock (Questa, 2005). In the case of Sycamore Creek, both natural and human factors almost certainly contribute to high conductivity. IBI score at SY2 was 20 (Poor), its lowest score since IBI score has ranged from 16 to 31 (Poor to Fair) at SY2 in 12 years of study (see Figure 6). The percentage of non-insects and tolerant BMIs was especially high this year, as has been a trend at study streams in drought years. 26 vertebrate species have been observed over the years at SY2, including 2 aquatic species: Pacific tree frog and red-eared slider (Trachemys scripta elegans), a non-native aquatic turtle observed in one of the deeper pools this year. Most likely, this turtle is an escaped pet, as they are known to survive well when released to the wild in California. This is thought to be the turtle observed in previous years that was mistaken for a native Pacific pond turtle (Actinemys marmorata) Figure 6: Sycamore Creek Watershed IBI Scores IBI Score Year SY1 SY2 Southern Coastal Santa Barbara Streams and Estuaries Bioassessment Program Page 30

31 Mission Creek Watershed M1 is located in lower Mission Creek just downstream of De la Guerra St. at an elevation of 40. Gradient is low at This is a HIGH DIST reach, with 49% undisturbed, 49% urban, and 2% agricultural lands in its upstream watershed of 6,799 acres. Peak elevation in the Mission Creek watershed is approximately 4,000. Habitat assessment score was 23 this year, and has ranged from 23 to 35 in 15 years of study. M1 is tightly abutted by homes and commercial uses along both of its banks, which are composed mostly of hard concrete walls, with rip rap armored earth banks in sections. The streambed is composed of cobble, gravel, and sand, and normally has gentle riffles and 0.5 to 3 deep pools. Riffle areas were dry this year, with residual pools present. The patchy riparian canopy at M1 was limited to a few mature sycamores, white alders and ornamental trees. Riparian canopy cover was 68%, and has ranged from 28 to 71%. Riparian understory herbs, vines, and grasses were thick in the streambed. 47% of the 43 plant species recorded at M1 are native. The habitat of lower Mission Creek is severely constrained and fragmented by adjacent urban development, road crossings, and the ½-mile long concrete channel beginning just upstream of M1. Noise, lighting, and human traffic impacts to the stream are high. M1: standing pools M1: dry riffles M2 is located in the old Mission Creek channel at Bohnet Park at 50 in elevation. Gradient is low at This is a HIGH DIST reach, with 24% undisturbed and 76% urban lands in its upstream watershed of 643 acres with a peak elevation of 400. Old Mission Creek, which historically was the main channel of Mission Creek, was cut off and replaced by the concrete channel north of U.S. 101 during the construction of the highway. Old Mission Creek now receives runoff only from urban areas and M2: continuous flow, riffle and pool habitat intact natural slopes of the Santa Barbara west side. Habitat assessment score at M2 was 40 this year, and has ranged from 20 to 45 in 12 years of study. Bohnet Park buffers the stream on both sides from nearby residential and commercial development. M2 has earthen, highly erodable banks that are armored with chain link curtains and large boulders in sections. The streambed is composed of angular cobble, gravel, sand, and finer sediments and has gentle riffles and shallow, small pools that are 0.5 to 1 deep and 4 to 6 wide. Stream flow was low but continuous through M2 this year, and stronger than at most study reaches. The riparian corridor has benefited from plantings of native species in The dense riparian canopy is dominated by maturing willows, sycamores, white alders, and black cottonwoods (Populus balsamifera trichocarpa) 20 Southern Coastal Santa Barbara Streams and Estuaries Bioassessment Program Page 31

32 to 40 feet high. Riparian canopy cover was 91% this year, and has ranged from 18 to 95%. Riparian understory herbs, vines, and grasses are somewhat patchy. 71% of the 52 plant species recorded at M2 are native. The restoration project also included the development of an upstream oxbow (i.e., bend) and bioswale intended to filter urban storm water, and later an ultraviolet disinfection system to reduce bacteria levels in the water. Besides storm water, the stream regularly receives surface flows from groundwater pumping. Noise, lighting, and human traffic impacts to the stream are high due to the popularity of Bohnet Park and the density of nearby development. M3 is located in upper Mission Creek at Rocky Nook Park at 400 feet in elevation. Gradient is high at This is a MOD DIST reach, with 80% undisturbed, 18% suburban, and 2% agricultural lands in its upstream watershed of 4,142 acres. Peak elevation in M3 s watershed is approximately 4,000. Habitat assessment score was 80 this year, and has ranged from 68 to 85 in 14 years of study. Other than day use areas and trails from Rocky Nook Park, M3 is immediately adjoined by a natural floodplain, natural rock and soil banks, and natural boulder-dominated streambed with riffles, cascades/falls and plunge pools. The streambed contains clean cobble and gravel deposits ideal for rainbow/steelhead trout spawning, and sand and fine sediment deposits in pools. This year stream flow at M3 was continuous but very low in riffles and cascades, and pools ranged from 0.5 to 2 deep. The riparian canopy at M3 is dominated by mature sycamore, coast live oak, and white alder. Riparian canopy cover was 93%, and has ranged from 85% to 99%. Riparian understory herbs, vines, and grasses were dense in the streambed due to the lack of scouring flows. 72% of the 60 plant species recorded at M3 are native. The habitat of upper Mission Creek is fragmented by several road crossings and grade drops. Noise, lighting, and human traffic impacts to the stream are moderate due to the popularity of Rocky Nook Park and nearby roads. M3: Watercress fills the channel due to low flow M4: old rock dam eroding, residual plunge pool M4 is located in Rattlesnake Creek, a tributary of upper Mission Creek that drains the Rattlesnake Canyon wilderness area. M4 is at 1,000 feet in elevation, and has a high gradient of This is a REF reach, with 98% undisturbed and 2% suburban lands in its upstream watershed of 1,376 acres. Peak elevation in the watershed is approximately 3,700. Habitat assessment score was 85 this year, and has ranged from 73 to 95 in 10 years of study. M4 flows through a narrow, natural canyon and has steep rock and soil banks, and a natural streambed formed in bedrock and boulders with riffles, cascades, falls and plunge pools. Substrate is similar to M3, and is also ideal for rainbow/steelhead trout spawning when sufficient flow is present. This year stream flow at M4 was not continuous. There was very low flow in some riffles, but other sections were dry, thus pools were isolated and stagnant. Pools ranged from 1 to 3 deep. The dense riparian canopy is composed of mature sycamore, coast Southern Coastal Santa Barbara Streams and Estuaries Bioassessment Program Page 32

33 live oak, and white alder. Riparian canopy cover was 98%, and has ranged from 93% to 100%. Riparian understory herbs, vines, and grasses are sparse due to heavy shading and near vertical bedrock canyon walls. 97% of the 38 plant species recorded at M4 are native. Rattlesnake Creek is fragmented by a large debris dam ¼-mile downstream of M4, which is a migration barrier to some aquatic species. The remains of an old rock dam create a waterfall 5 high at the upper end of M4, although this impediment is eroding and was 15 high just a few years ago, and there are several natural falls upstream. Noise, lighting, and human traffic impacts to the stream are low at M4 due to its limited accessibility. M1 had lower than normal water temperature (16.0 ºC) and ph (7.4), and moderate specific conductance (1,193 µs). Dissolved oxygen was very low (2.2 mg/l) in residual pools due to the lack of stream flow and circulation. M2, which had continuous stream flow, had similar water chemistry readings as in previous years, with moderate temperature (18.9 ºC) and ph (8.2), optimal dissolved oxygen (9.8 mg/l), and elevated specific conductance (1,267 µs). Both M1 and M2 are subject to significant pollutant inputs from urban runoff. M3, which had continuous flow, had similar water temperature (15.6 ºC), dissolved oxygen (9.2 mg/l), ph (7.9) and specific conductance (1,148 µs) compared to previous years. Water quality is generally good at this site, with only minor pollution inputs expected due to the low level of development upstream. M4, which was limited to standing pools this year, had similar temperature (15.6 ºC), ph (7.4) and specific conductance (956 µs) compared to previous years, but like M1 had very low dissolved oxygen (2.5 mg/l) due to a lack of surface flow and circulation. IBI score at M1 was 0 (Very Poor) this year, and 9 (Very Poor) at M2 (see Figure 7). IBI score has been in the Very Poor or lower Poor range at both sites over the years. These sites are both characterized by low proportion of sensitive taxa, EPT taxa, predators and shredders, low EPT and insect richness, and high proportion of tolerant taxa. As was case this year, M2 typically scores slightly better than M1. IBI score at M3 was 32 (Fair), which is on the lower end for this study reach, which typically scores from Fair to Good. Low flow levels and drying over last summer is a probable cause of lower IBI score, as M3 had only standing pools in September IBI score at M4 was 4 (Very Poor) this year, which is a drastic drop from last year, when the stream scored 48 (Good). M4 is a REF study reach and typically scores in the Good to Excellent range. The prolonged drought has severely impacted this study reach, which had only standing pools last September (2014), and at the time of this year s spring survey. The lack of riffle habitat and extremely low dissolved oxygen levels in residual pools created inhospitable conditions this year for many BMI taxa that typically inhabit M4. The effects of the drought on M4 are even more dramatic than those of the Jesusita Fire of 2009, which burned the majority of the upper Mission Creek watershed, and coupled with erosive flood flows the following winter caused a drastic drop in IBI scores at M4 (13, Poor) and M3 (20, Poor) the following spring. A total of 25, 24, 29, and 21 vertebrate species have been observed over the years at M1, M2, M3, and M4. Pacific tree frogs have been observed at all 4 study reaches. Three-spined stickleback and mosquitofish (non-native) have been observed at M1. California newts (Taricha torosa) were observed at M4 this year, but not at M3. Rainbow trout were not observed at M3 or M4 this year. Newts and trout were regularly observed at both M3 and M4 in the past. Trout have not been seen at either study reach since the Jesusita Fire in May 2009, which combined with strong scouring flows and erosion the following winter devastated the landscape Southern Coastal Santa Barbara Streams and Estuaries Bioassessment Program Page 33

34 and stream community. While the BMI community and California newt populations appeared to recover from the fire effects over 2 to 3 years, trout have not recolonized M3 or M4. California tree frog (Pseudacris cadaverina) has been observed at M4. IBI Score Figure 7: Mission Creek Watershed IBI Scores Year M1 M2 M3 M4 Arroyo Burro Watershed AB1 is located in lower Arroyo Burro just upstream of the north end of Alan Rd. at an elevation of 25. Gradient is low at This HIGH DIST reach has 51% undisturbed, 38% urban, 7% agricultural and 4% herbaceous lands in its upstream watershed of 5,646 acres. Peak elevation in the Arroyo Burro watershed is approximately 4,000. Habitat assessment score was 55 this year, ranging from 53 to 55 in 13 years of study. AB1 is bordered by vacant land and natural hills to the west, and a wide riparian/upland buffer and Las Positas Rd. to the east. Stream banks are moderately steep and sandy, and stream flow was continuous through gentle cobble and gravel riffles and sand-bottomed pools 1 to 4 deep. Lower Arroyo Burro, fed by Veronica Springs, is among the most consistent perennial streams in the study area. The patchy riparian canopy at AB1 is mostly willows, with a few coast live oaks and young sycamores and white alders. There are also stands of invasive non-native Arundo donax. Riparian canopy cover was 85% this year, and has ranged from 40% to 97%. Riparian understory herbs, vines, and grasses were dense in the streambed and banks. 54% of the 56 plant species recorded at AB1 are native. Lower Arroyo Burro is highly fragmented by urban development and several grade drops, while noise, lighting, and human traffic impacts to the stream are moderate to high. Good riffle and pool habitat at low gradient AB1 Southern Coastal Santa Barbara Streams and Estuaries Bioassessment Program Page 34

35 AB5 is the downstream most section of Mesa Creek where it empties into Arroyo Burro estuary at 10 elevation. Mesa Creek drains a small, mostly urbanized (70%) watershed of 275 acres. Peak elevation in the watershed is approximately 400. AB5 (HIGH DIST) is bordered by natural hills to the south, and Cliff Dr. to the north with a wide intervening riparian corridor. Habitat assessment score was 45 this year, and has ranged from 38 to 48 in 9 years of study. AB5 was daylighted in 2007, prior to which it was an underground storm drain. AB5 has soil and clay bedrock banks, a narrow, 3 wide channel bottom with poorly developed substrate that consists mostly of soft muds, and bedrock, with some angular gravel and cobble. Planted in 2007, riparian vegetation is dominated by dense willows and alders up to 30 high, and the understory is also dense. 79% of the 43 plant species recorded at AB5 are native. Riparian canopy cover was 100% this year, as in the previous 3 years. Mesa Creek is highly fragmented by urban development and road crossings. Noise, lighting, and human traffic impacts to the stream are moderate to high. AB7 and AB8 (both HIGH DIST) in Las Positas Creek, a small tributary of lower Arroyo Burro, are very similar and are separated by an approximately ¼-mile long open concrete channel. Las Positas Creek has a watershed area of 355 acres and is 43% urban, 17% wilderness, 2% agriculture, and 38% herbaceous, most being the Santa Barbara golf course. Peak elevation in the watershed is approximately 250. Currently, the City of Santa Barbara is exploring options for this section Las Positas Creek, inclusive of AB7, AB8, and the concrete channel, which is open to direct sunlight, causing pulsed increases in water temperature. Habitat assessment score was 28 at AB7 and AB8 this year. AB7 and AB8 are straightened, approximately 20 wide from top of bank to bank, and tightly abutted by Las Positas Rd. to the east and homes to the west. The banks and sections of the streambed were densely vegetated, predominately by willows and a mix of native and non-native understory plants, and are soil with sections of exposed bedrock and riprap, with concrete wing walls at road crossings. Exposed bedrock creates pools with intervening falls and riffles, and stream bottom substrate includes exposed bedrock, angular cobble and gravel, sand and fines. Flow in both study reaches was very low but continuous, with a trickle in falls and riffles. The stream is highly fragmented by adjoining residential areas and road crossings. Riparian canopy cover was 93% at AB7 and 92% at AB8. 56% of the 16 plant species recorded at AB7 are native, compared with 59% of 17 at AB8. AB7: dense horsetails in channel bottom (above) Concrete channel (above) between AB7 and AB8 (below) AB5 (below): clay substrate, dense native riparian vegetation Southern Coastal Santa Barbara Streams and Estuaries Bioassessment Program Page 35

36 Noise, lighting, and human traffic impacts to AB7 and AB8 are very high. As in previous years, AB1 had cool water temperature (15.9 ºC), normal ph (7.9), optimal dissolved oxygen (8.9 mg/l) and elevated specific conductance (1,886 µs). Water chemistry readings at AB7 (15.9 ºC, 7.9, 8.9 mg/l, and 1,669 µs) and AB8 (15.4 ºC, 7.9, 10.5 mg/l, and 2,305 µs) were similar. The weather was cloudy and approximately 65 ºF when AB7 and AB8 were surveyed, thus there was not a substantial warming effect from the concrete channel, as often occurs on warm, sunny days. AB5 had cool water temperature (15.9 ºC), normal ph (7.9), and optimal dissolved oxygen (8.9 mg/l). Specific conductance (4,089 µs) was very high as in all previous years of study. While the high conductivity levels at the lower Arroyo Burro watershed study reaches is likely contributed to by naturally hard ground water inputs from springs and seeps, pollutant inputs from urban runoff are also expected to be a contributing factor. AB1 had an IBI score of 17 (Poor) this year, and has ranged from 6 to 25 in 13 years of study (see Figure 8). AB5 had an IBI score of 5 (Very Poor), ranging from 4 to 14 over 9 years. IBI scores at AB7 and AB8 this year were 23 and 13, respectively (both Poor). The lower Arroyo Burro watershed sites have an impaired BMI community (especially AB5) generally characterized by low proportion of sensitive taxa, EPT taxa, predators and shredders, low EPT and insect richness, and high proportion of tolerant taxa. However, these sites have had perennial flow despite the recent drought, and IBI scores have generally been higher compared to study reaches in the lower reaches of other nearby streams that have experienced drying effects in recent years (e.g., Mission and Sycamore Creeks). A total of 31, 22, 10, and 8 vertebrate species have been observed at AB1, AB5, AB7, and AB8. Three-spine sticklebacks and Pacific tree frogs have been observed at all 4 study reaches. 30 Figure 8: Arroyo Burro Watershed IBI Scores IBI Score Year AB1 AB5 AB7 AB8 Southern Coastal Santa Barbara Streams and Estuaries Bioassessment Program Page 36

37 San Jose Creek Watershed SJ2 is located in the middle reach of San Jose Creek approximately ¼-mile upstream of the Patterson Rd. crossing at an elevation of 120. Gradient is low at SJ2 (MOD DIST) has 81% undisturbed, 16% agricultural, and 1% each suburban and herbaceous lands in its upstream watershed of 3,836 acres. Peak elevation in the San Jose Creek watershed is approximately 3,100. Habitat assessment score was 63 this year, and has ranged from 50 to 65 in 15 years of study. Above its banks SJ2 is bordered by a single family residential neighborhood to the west and avocado orchards to the east. The stream has steep, 20 -high natural soil banks with some loose riprap and old pipe and wire revetment present. The streambed is composed of small boulders, cobble, gravel, and sand, and has cobble riffles and 0.5 to 3 deep pools. Pools have substantial deposits of fine sediments, presumably due to increased soil erosion from upstream orchards. Flow was continuous through SJ2 and stronger than at most other study streams. The riparian corridor is in width, containing many mature cottonwoods and sycamores of 50 or more in height, and a generally dense understory covering the banks and much of the streambed. 67% of the 49 plant species recorded at C1 are native. Riparian canopy cover was 72%, and has ranged from 66 to 99%. There is moderate fragmentation caused by partial barriers at several downstream road crossings. Noise, lighting, and human traffic impacts at SJ2 are moderate. SJ2: Riffles with adequate flow (above), drainpipe from orchards, eroding exposed streambank Similar to most years, SJ2 had favorable water temperature (14.5 ºC), ph (7.8) and dissolved oxygen (8.9 mg/l), but high specific conductance (2,337 µs), likely indicating that there are at least some pollution inputs from agricultural runoff. Specific conductance has exceeded 2,000 µs the past 3 years, but did not exceed 1,700 µs in any previous year. The prolonged drought and lack of rainwater has contributed to the rise in dissolved mineral concentration over the last few years. However, unlike many other study reaches, flow has been perennial at SJ2 throughout the recent drought. IBI score at SJ2 was 40 (Fair) this year, and has ranged from 23 to 46 (Poor to Good) over the years (see Figure 9). 32 vertebrate species have been observed. Pacific tree frogs, three-spine sticklebacks, and arroyo chub (non-native) have been commonly observed, as have a few rainbow trout, which have been seen in much greater numbers in past years in upstream study reach SJ3 near the San Marcos Trout Club community. Southern Coastal Santa Barbara Streams and Estuaries Bioassessment Program Page 37

38 50 Figure 9: San Jose Creek (SJ2) IBI Scores 40 IBI Score Year Arroyo Hondo Watershed AH0, studied for the first time this year, is in Arroyo Hondo just upstream of the U.S. 101 crossing. The stream passes through a 300 -long concrete channel/culvert underneath U.S. 101, in which weirs were constructed in 2012 to facilitate fish passage upstream from the ocean (see photo to right). AH0 is at 10 elevation and has a low gradient of Peak elevation in the watershed is approximately 2,900. This MOD DIST reach has nearly 100% wilderness lands in its upstream watershed of 2,817 acres. Approximately 0.2% of the watershed area is occupied by the Arroyo Hondo adobe, barn, and small orchards. AH0 is bordered by U.S. 101 to the south, natural upland slopes to the west, and a dirt road and small orchard to the east. Habitat assessment score was 70. Stream banks are natural soil and rock and densely vegetated. Streambed substrate includes natural boulders, cobble, gravel and sand. Boulder/cobble riffles were dry thorough most of the study reach, with water limited to a 50 long by 20 -wide, 1-2 deep pool just above the concrete culvert. There was a trickle of flow beginning at the concrete culvert and continuing downstream to the large pool on the beach. The riparian corridor is wide. The dense riparian canopy is composed of mature sycamore, coast live oak, and white alder. Riparian canopy cover was 100%. Riparian understory herbs, vines, and grasses are dense. 79% of the 29 plant species recorded at AH0 are native. The concrete culvert is likely still a partial barrier to movement for some aquatic species, although the weirs have improved the situation. There are no other manmade barriers upstream. Noise, lighting, and human traffic AH0: upstream view towards AH0 from concrete culvert under U.S. 101 (above) and downstream view from standing pool towards culvert (below) Southern Coastal Santa Barbara Streams and Estuaries Bioassessment Program Page 38

39 impacts to the stream are low/moderate, at AH0 due to the proximity of U.S AH1 is located in Arroyo Hondo approximately 1 mile upstream of U.S. 101 at an elevation of 150. This REF study reach has moderate gradient (0.04) and a watershed area of 2,583 acres that is 100% undisturbed wilderness. A dirt road that extends along the stream about ¼-mile upstream of the study reach is the only human disturbance. Habitat assessment score was 93 this year, had has been between 93 and 95 in 15 years of study. The stream has natural soil and rock banks and natural boulder-dominated streambed with riffles, cascades/falls and plunge pools. The streambed contains clean cobble and gravel deposits ideal for rainbow/steelhead trout spawning, and sand and fine sediment deposits in pools. This year stream flow at AH1 was low but continuous in riffles and cascades, and pools ranged from 1-3 deep. The riparian canopy at AH1 is dominated by mature sycamore, coast live oak, and white alder. Riparian canopy cover was 99%, and has ranged from 91 to 100%. Riparian understory herbs, vines, and grasses were patchy, as much of the stream banks are made up of large boulders. 81% of the 48 plant species recorded at AH1 are native. Besides the U.S. 101 crossing, there is little habitat fragmentation in Arroyo Hondo, and human traffic impacts to the stream are very low. AH1: cool clean water, ideal substrate for trout spawning. AH0, which was limited to standing pools this year, had favorable temperature (16.6 ºC), ph (7.1) and specific conductance (1,092 µs), but very low dissolved oxygen (2.1 mg/l) due to a lack of surface flow and circulation. AH1, which has had perennial flow throughout the recent drought, had optimal water temperature (15.0 ºC), dissolved oxygen (10.3 mg/l), and ph (8.1). Specific conductance (1,126 µs) was favorably low compared to most other study reaches this year, but more than 25% higher compared to any previous year at AH1, indicating that mineral concentrations in the water have become more concentrated due to the drought. IBI score at AH1 was 55 (Good), and this REF stream has typically scored in the Good or Excellent range in previous years of study (see Figure 10). IBI score at AH0 was 3 (Very Poor). AH0 would be expected to score in the Good to Excellent range when there is sufficient flow and adequate dissolved oxygen. The lack of riffle habitat and extremely low dissolved oxygen levels in residual pools created inhospitable conditions this year for most BMI taxa. 14 vertebrate species were observed at AH0 this year, including red-legged frogs (Rana draytonii) and Pacific tree frogs. 36 vertebrate species have been observed over the years at AH1, including 5 aquatic species. AH1 was the only stream study reach with rainbow trout this year. Other aquatic vertebrates observed at AH1 over the years include southwestern pond turtle, two-striped garter snake (Thamnophis hammondii), Pacific tree frog, and California tree frog. Southern Coastal Santa Barbara Streams and Estuaries Bioassessment Program Page 39

40 80 Table 10: Arroyo Hondo Watershed IBI Scores IBI Score AH0 AH1 Year Gaviota Creek Watershed GAV1 is located in lower Gaviota Creek just upstream of the crossing of the entrance road into Gaviota State Beach at an elevation of 15. Gradient is low at GAV1 (MOD DIST) has 59% undisturbed 40% grazed herbaceous and 1% urban (i.e., roads) lands in its upstream watershed of 12,791 acres. Peak elevation in the watershed is approximately 2,700. Habitat assessment score was 80 this year, and has ranged from 68 to 85 in 12 years of study. The stream has low, gradually sloped sandy soil banks and a wide floodplain with a thick willow-dominated riparian forest that also includes coast live oaks, sycamores, black cottonwoods, and dense understory plants. Due to a lack of scouring flows the past few years, riparian vegetation has become thick in the streambed, as evidenced by 94% riparian canopy cover this year. This parameter had ranged from 0-80% in previous years. 65% of the 60 plant species recorded at GAV1 are native. The streambed at GAV1 has gentle cobble-dominated riffles and 0.5 to 3.0 deep pools underlain mostly by sand and fine sediments. GAV1: thick riparian canopy with watercress filling much of streambed Flow was reduced to a trickle in riffles at the time of the spring survey this year, as it has been in the past few years. The downstream access road crossing and several upstream crossings by U.S. 101 create grade changes that inhibit movement by most fish and other aquatic species, thus partially fragmenting the aquatic habitat. Noise, lighting, and human traffic impacts at GAV1 from U.S. 101 and Gaviota State Beach are moderate. LC1 (MOD DIST) is located in Las Canovas Creek just upstream of its confluence with Gaviota Creek at an elevation of 320. This site is high gradient (0.06) and drains an upstream watershed of 1,024 acres that is comprised of 89% undisturbed wilderness, 11% herbaceous lands, and less than 0.5% urbanized lands including a paved road and several rural residential structures. Peak elevation in the watershed is approximately 2,700. LC1 is abutted by the paved road above its northern bank, and wilderness to the south. Habitat assessment score Southern Coastal Santa Barbara Streams and Estuaries Bioassessment Program Page 40

41 was 73. The stream has steep rock and soil banks that are actively eroding. The northern bank has been fortified in sections with loose boulders in an effort to protect the access road. The boulder-dominated streambed has alternating falls/cascades and pools of 1 to 3 deep. Flow was low but continuous throughout LC1. Fine sediments largely embed underlying cobble and gravel deposits in much of the streambed, particularly in pools. Mature alders, sycamores, and coast live oaks form a dense riparian canopy (94% cover), with dense understory plants. 74% of the 23 plant species recorded at LC1 are native. The culvert connecting Las Canovas Creek to Gaviota Creek under U.S. 101 creates a grade drop that likely inhibits movement of most fish and other aquatic species. Noise, lighting, and human traffic impacts at LC1 are light. GAV1 had low stream temperature (15.1 ºC), optimal dissolved oxygen (7.3 mg/l), normal ph (7.7), and elevated conductivity (2,518 µs), as has been the case for the last several years. Comparatively, tributary LC1 had lower temperature (14.3 ºC), higher dissolved oxygen (10.4 mg/l) and ph (8.2), and much lower conductivity (838 µs). IBI score was 11 (Poor) at GAV1 this year, its lowest score in 12 years of study, and slightly worse than last year (14, Poor) (see Figure 11). The past two years, GAV1 has had low insect/ept richness and representation by other sensitive taxa, predators, and shredders, and a high proportion of tolerant taxa including chironomids and non-insects, which made up about 80% of the sample this year and 70% last year. IBI scores have varied widely at GAV1 over the years, having been as high as 54 in 2013, and reaching the Good category several times. As with many other streams, the drought appears to have limited the BMI community at GAV1 the past two years, it dried to the point of having standing pools only, and presumably low dissolved oxygen levels, in September 2013 and LC1 had an IBI score of 43 (Fair), having high EPT and insect family richness, fair representation by other sensitive taxa and shredders+predators, and fairly high proportion of tolerant taxa, particularly gastropods and chironomids. This site has continued to have perennial flow despite the recent drought, as observed in September 2014 and vertebrate species have been observed at GAV1 over the years, including 5 aquatic species: three-spine sticklebacks, arroyo chubs, southwestern pond turtles, western toads, and Pacific tree frogs. 13 vertebrate species were observed at LC1 this year, including California newts and Pacific tree frogs. Figure 11: Gaviota Creek Watershed IBI Scores IBI Score Year GAV1 LC1 Southern Coastal Santa Barbara Streams and Estuaries Bioassessment Program Page 41

42 2. Drought Effects Table A-5 in the Appendix summarizes the results of the ANOVAs comparing IBI scores by disturbance group (REF, MOD DIST, and HIGH DIST) for the 3 flow groups: 1. (F-F): Flow in spring and Flow previous fall 2. (F-P): Flow in spring, Pools only or dry previous fall 3. (P-P): Pools in spring, Pools only or dry previous fall There were not discernable differences in IBI score among flow groups at HIGH DIST sites, as apparently the high level of human disturbance impacts masked any effects from the drought. For REF sites, mean IBI score was significantly higher for the F-F group (51) compared to F-P (22) and P-P (4) groups (p=0.0006, r 2 = 0.77). Results for MOD DIST sites were similar (mean IBI score 44 for F-F group, 18 for F-P group, 3 for P-P group, <0.0001, r 2 = 0.74). We combined the REF and MOD DIST groups to improve statistical power (i.e., due to a greater number of samples). Differences in mean IBI score were highly significant between the F-F (47), F-P (19), and P-P (4) groups (p<0.0001, r 2 = 0.74). Figure 12 illustrates the results for the HIGH DIST and REF+MOD DIST groups. All 7 BMI core metrics had far better values for F-F compared to F-P and P-P groups for the REF+MOD DIST groups, all with high levels of significance (p range < to , r 2 range 0.42 to 0.64) (see Table A-5). The results with respect to IBI scores and core metrics show that where stream flow is intermittent the aquatic community is stressed due to loss of riffle habitat, stagnation of residual pools and low dissolved oxygen levels, or complete drying. In such conditions, many aquatic inhabitants become limited or disappear including vertebrates such as steelhead/rainbow trout and other fish, and many sensitive BMIs including Caenidae, Lepidostomatidae, Glossostomatidae, Rhyacophilidae, and Elmidae, all of which had significantly (p<0.05) or near-significantly (0.05<p 0.10) higher abundances for the F-F group compared to F-P and P-P groups for REF+MOD DIST sites (see Table A-5). What persists in these stressed conditions or rapidly recolonizes when flow returns are some amphibians (e.g., tree frogs) and tolerant BMIs including Chironomidae, Dytisidae, and Simulidae, all of which had significantly or near significantly higher abundances in the F-P group compared to the F-F group. Interestingly, mean BMI density was not different between flow groups for REF+MOD DIST sites (p=0.32, r 2 = 0.08). 3. Year-to-Year Trends in IBI Scores The results of the ANOVA of IBI score year to year for the REF group (n=66) are summarized in Table A-6. Figure 13 illustrates the ANOVA. Using only REF sites eliminated any potentially confounding influences of human disturbance on IBI scores, allowing the relationship between IBI scores and rainfall to be more clearly examined. Southern Coastal Santa Barbara Streams and Estuaries Bioassessment Program Page 42

43 Figure 12: ANOVA Comparisons of IBI Score for F-F (Perennial), F-P (Intermittent) and P-P (Intermittent) Flow Groups at HIGH DIST and REF+MOD DIST Stream Reaches Means and distributions of IBI score by flow group (F-F, F-P, and P-P) for HIGH DIST and REF+MOD DIST disturbance groups are shown below. Top and bottom of diamonds are the 95 percent confidence limits, and the center lines are the means for each flow group. The lower and upper lines are the 25 percent and 75 percent quantiles. The p value is for the ANOVA where IBI score is the dependent variable and flow group is the independent variable. R 2 is the proportion of variation in the dependent variables accounted for by the independent variable. HIGH DIST Reaches: n=27, r 2 =0.08, p=0.39 REF+MOD DIST Reaches: n=31, r 2 =0.74, p< Southern Coastal Santa Barbara Streams and Estuaries Bioassessment Program Page 43

44 Figure 13: ANOVA Comparisons of IBI Score for REF Study Reaches by Year Means and distributions of IBI score for REF study reaches by year are shown below. Top and bottom of diamonds are the 95 percent confidence limits, and the center lines are the means for each dis group. The lower and upper lines are the 25 percent and 75 percent quantiles. The p value is for the ANOVA where IBI score is the dependent variable and year is the independent variable. R 2 is the proportion of variation in the dependent variables accounted for by the independent variable. (p<0.0001, r 2 = 0.59, n=66). Southern Coastal Santa Barbara Streams and Estuaries Bioassessment Program Page 44

45 The REF group had significantly lower IBI scores for three years compared to most of the other years: , which had a mean IBI score of 37 and was the second highest rainfall year in over 130 years of records, and: , which had a mean IBI score of 33, and was the 3 rd consecutive year of severe drought, and one of the lowest rainfall years on record , which had a mean IBI score of 24, and was the 4 th consecutive year of severe drought, and one of the lowest rainfall years on record. There were not any other significant differences in mean IBI score among years for the REF streams. The remaining years had average IBI scores ranging from 47 to 63. Based on the above, IBI scores appear to be naturally lower immediately following extremely high rainfall years, and after periods of prolonged drought, compared to more moderate rainfall years. This makes sense, as: Extremely high rainfall years produce high stream discharges that scour and wash out large quantities of streambed material and BMIs in some sections, and bury them in others. The following spring, the BMI community is in a state of recovery, as evidenced by lower overall BMI density, lower relative abundances of many taxa such as pool dwelling Caenidae and Leptohyphidae, Ostracoda, and Gastropoda, and higher relative abundances of early colonizers including Baetidae and Simulidae. Periods of prolonged drought (i.e., 2011 to 2015) can result in the loss of surface flow in normally perennial streams. When surface flow ceases, aquatic habitat becomes greatly reduced (i.e., standing pools with dissolved oxygen crashes) or is completely lost (dry), and relatively few aquatic taxa can survive. The aquatic community begins to recover when stream flows return via colonization from remaining wet reaches of the stream or other watersheds (e.g., by aerial insects). This state of recovery is typically reflected by lower BMI community integrity (and lower IBI scores) when surveys are completed the following spring. More normal rainfall years typically create more stable and sustained flows, which create the conditions for a more balanced and mature BMI community, and more stable, higher IBI scores. The ANOVAs comparing IBI score by disturbance group for each year summarized in Table A-7, and Figure 14 illustrates the ANOVAs for select years (2012 and 2015). From 2000 to 2014, there were significant differences amongst the disturbance groups in mean IBI score, which increased appropriately from HIGH DIST to MOD DIST to REF every year. This includes 2005, the extreme high rainfall year, and 2014, which followed three consecutive years of drought. MOD DIST and REF scores were depressed in 2005 and 2014, but the IBI still differentiated appropriately between each disturbance group. This year (2015) was the first time that there were not any significant differences in mean IBI score between disturbance groups. The prolonged drought caused intermittent flow conditions in 2014 and 2015 at 2 of the 3 REF study reaches, M4 (IBI score 4, Very Poor) and C3 (IBI score 14, Poor). These study reaches have typically scored in the Good to Excellent range in years of perennial flow. AH1 was the only REF study reach with year-round flow the past two years, and had an IBI score of 55 (Good). Southern Coastal Santa Barbara Streams and Estuaries Bioassessment Program Page 45

46 Figure 14: ANOVAs of IBI Score for HIGH DIST, MOD DIST, and REF Disturbance Groups for Selected Years Means and distributions of IBI score for each of the three disturbance groups for selected years (2012 and 2015) are shown below. Top and bottom of diamonds are the 95 percent confidence limits, and the center lines are the means. The lower and upper lines are the 25 percent and 75 percent quantiles (p<0.0001, r 2 = 0.85, n=14) 2015 (p=0.2497, r 2 = 0.19, n=16) Southern Coastal Santa Barbara Streams and Estuaries Bioassessment Program Page 46

47 C. Estuaries The following discusses the physiochemical attributes and BMI communities of each individual estuary and their respective watersheds. Photographs are also provided. See Table A-4 for a summary of data collected at the study estuaries. 1. Study Estuaries Carpinteria Creek Estuary The Carpinteria Creek estuary (MOD DIST) has an upstream watershed of approximately 9,600 acres, including approximately 80% wilderness, 17% agriculture, and 3% urban development. The estuary is approximately 800 long by wide, and had a maximum depth of 2.5 feet deep in the center, as compared to 4 deep last year. The width, depth, and overall volume of water were noticeably lower this year, as was the case in all the study estuaries due to the drought. The estuary was closed from the ocean by an approximately 150 wide sand berm. Tide conditions were high at the time of the survey. Bottom substrate was mostly sand. There was a thin surface layer of fine sediment and organic detritus along most of the bottom area, with scattered clumps of submerged algae and organic litter. There are sand dunes along the southern boundary of the estuary, and fringing vegetation ranged from in width and was composed of approximately 80% natives including cattails, pickleweed, and salt grass, and 20% non-natives including iceplant and ornamental shrubs. The estuary is abutted to the east and west by campgrounds of Carpintera State Beach, and is bisected by a bridge. There is heavy human traffic in this area from the adjacent campsites, bridge, and State beach. Habitat assessment score was 53/100. Carpinteria Creek estuary: wide beach berm and lower water level compared to previous years. Water chemistry measurements were taken at the surface and at 1.5 depth near the downstream end of the estuary. Water surface temperature was 23.4 ºC, salinity was 1.5 ppt, dissolved oxygen was low at 3.6 mg/l, and ph was 7.8. Near the bottom temperature was 23.0 ºC, salinity was 1.4 ppt, and dissolved oxygen was 3.5 mg/l. Like last year, the water column was well mixed, but surprisingly salinity was lower compared to last year (5.2 ppt), as was dissolved oxygen (6.5 mg/l last year). A total of 7 different BMI taxa were observed at the Carpinteria Creek estuary this fall, and BMI density was high at 2,143/m 2, as compared to 9 taxa and 3,000/ m 2 last year. Chironomidae Southern Coastal Santa Barbara Streams and Estuaries Bioassessment Program Page 47

48 was the most abundant taxa, and Oligochaeta, Cladocera, Gastropoda, and Baetidae were found in significant numbers. These taxa were all found in significant numbers last year. Sycamore Creek Estuary Sycamore Creek estuary (HIGH DIST) has an upstream watershed of approximately 2,600 acres, including approximately 43% wilderness, 55% urban development, and 2% agriculture (mainly orchards). Upstream of Cabrillo Blvd., the estuary is a channelized extension of Sycamore Creek, and approximately wide and 1-2 deep in the center. This section was not surveyed due to access problems. Downstream of Cabrillo Blvd. the estuary stretched along the beach for approximately 30 long and wide at the time of the field survey on September 23. The estuary was closed to the ocean by a natural sand berm of approximately 150 wide. Tide conditions were low at the time of the survey (11 AM). The estuary was smaller and shallower (1.5 maximum depth) compared to previous years. Bottom substrate was mostly sand. There was a thin surface layer of fine sediment and organic detritus along most of the bottom area, and scattered clumps of submerged algae, submerged grass, and organic litter. Fringing vegetation ranged from 0-10 wide around the estuary, and was composed of approximately 20% native and 80% non-native cover. There is heavy human traffic in this area from the adjacent roadways, boardwalk, and beach. Habitat assessment score was 20/100. Water surface temperature was 25.7 ºC, salinity was high at 9.1 ppt, dissolved oxygen was 14.6 mg/l, and ph was 8.6. Near the bottom temperature was 24.4 ºC and salinity was 9.1 ppt. Overall, the water column was well mixed, and salinity was about half of last year (19.1 ppt). Above: Estuary perimeter reduced due to drought, vegetation growing in previously inundated area (mid-right). Below: Submerged grass bed in remaining estuary at Cabrillo Blvd. bridge. This fall, a total of 7 BMI taxa were observed and BMI density was 3,000/ m 2, compared to 6 taxa and 1,579/ m 2 last year. The most abundant taxa this year were Corixidae, Ostracoda, and Chironomidae, also with some Oligochaeta and Polychaeta. BMI composition was similar last year. Southern Coastal Santa Barbara Streams and Estuaries Bioassessment Program Page 48

49 Mission Creek Estuary The Mission Creek estuary (HIGH DIST) has an upstream watershed of approximately 6,900 acres, including approximately 48% wilderness, 50% urban development, and 2% agriculture (mainly orchards). Upstream of Cabrillo Blvd., the estuary is a channelized extension of Mission Creek, and approximately 40 feet wide and 4 to 5 feet deep in the center. This section was not surveyed due to access problems. Downstream of Cabrillo Blvd. the estuary stretched along the beach for approximately 600 in length and wide on September 23. The estuary did not connect with the Laguna Channel to the east as it has in previous years. The estuary was closed from the ocean by an approximately 100 wide sand berm at mid-tide. Maximum water depth was 3, and bottom substrate was mostly sand. There was a thin surface layer of fine sediment and organic detritus along most of the bottom area, and scattered clumps of submerged algae and grass and organic material. Sand dunes along the northern boundary of the estuary are sparsely vegetated with ice plant and a few native shrubs and herbs. Fringing marsh vegetation including cattails, pickleweed and non-native grasses were more prominent and wider (up to 20 ) along the western and eastern edges compared to previous years. Overall, vegetation was approximately 40% native and 60% non-native in overall cover. There is heavy human traffic in this area from the adjacent roadways, boardwalk, Stern s Wharf and the beach. Habitat assessment score was 40/100. Above: westerly view across the estuary. Below: northerly view across the estuary, notice marsh vegetation establishing along northern fringe. Water chemistry and BMI sampling was conducted along the southern margin end nearest the ocean. Water chemistry was fairly uniform with depth, with temperatures of ºC, salinity of ppt, dissolved oxygen of 14.0 mg/l, and ph of BMI taxa were observed at the Mission Creek estuary this fall, and BMI density was low at 288/m 2, as compared with 10 BMI taxa and BMI density of 1,765/m 2 last year. Ostracoda comprised about half of the BMIs collected this year, and Chironomidae, Amphipoda (Gammaridae), and Baetidae were also present. Southern Coastal Santa Barbara Streams and Estuaries Bioassessment Program Page 49

50 Arroyo Burro Estuary Arroyo Burro estuary (HIGH DIST) has an upstream watershed of approximately 6,800 acres, including approximately 49% wilderness, 4% herbaceous open space, 7% agriculture (mainly orchards), and 40% urban development. The upstream inlet to the estuary is just below the Cliff Drive bridge. The estuary was approximately 1,500 long, wide, and up to 4 deep at the time of the September 23 survey. For the majority of its length, this estuary is bordered by natural scrub vegetation and cliffs to the east, and Hendry s beach and parking area to the west. The northern upstream portion of the estuary is surrounded by thick, mostly native marsh and riparian forest of in width that was enhanced by a major habitat restoration project undertaken by the City. Northerly view from downstream end of the estuary. Mouth closed to ocean, which is unusual for this site. The estuary was closed to the ocean by a 50 -wide beach berm at the time of the September 23 survey during mid-tide conditions. Bottom substrate was composed mostly of sand, with a thin layer of fine sediments and detritus and scattered algae and organic material. Some cobble and gravel was present nearest the upstream end. Noise, lighting and human traffic impacts are high. Habitat assessment score was 50/100. Water chemistry and BMI sampling was conducted at the downstream estuary margin. Unlike past years, there was no stratification of water chemistry readings with depth. Water temperature was ºC, salinity ppt, dissolved oxygen 12.9 mg/l, and ph 8.3. Oddly, only 2 BMIs (both Chironomidae) were found in the samples collected at the Arroyo Burro estuary this year. BMI density has typically ranged from 800-2,500/m 2 in past years, and 5-10 different BMI taxa have been found. 50 to long Striped Mullet (Mugil cephalus) were observed schooling in the lower estuary, and bird activity was heavy as usual in and around the estuary. Southern Coastal Santa Barbara Streams and Estuaries Bioassessment Program Page 50

51 Goleta Slough Estuary The Goleta Slough estuary (HIGH DIST) has the largest watershed area of all study estuaries at 30,400 acres, and receives runoff from several major tributary streams including Tecolotito Creek, San Jose Creek, San Pedro Creek, Maria Ygnacio Creek, and Atascadero Creek. The watershed consists of 53% wilderness, 25% agriculture, 20% urban, and 2% herbaceous undeveloped lands. The 430-acre Goleta Slough wetlands include the approximately 1,200 long, wide estuary along Goleta Beach, upstream creek and tidal channels, salt marsh, salt flats and freshwater marsh. The estuary was up to 5 deep and closed to the ocean by a 100 wide sand berm at the time of the September 23 survey during high tide conditions. The estuary is bordered by 100 high cliffs and natural scrub and wetland vegetation to the north and Goleta Beach including the Beachside restaurant and pier parking area to the south. The southern banks are armored with riprap to protect the parking area, and vegetation in this area is sparse and composed mostly of ornamental shrubs. The estuary bottom substrate was composed mostly of sand, with a thin layer of fine sediments and detritus and scattered algae and organic material. Noise, lighting and human traffic impacts are high. Habitat assessment score was 53/100. Water chemistry and BMI sampling was conducted at the southern, downstream estuary margin. Water chemistry readings were uniform with depth, with very high water temperature ( ºC) and dissolved oxygen (22.5 mg/l), high salinity ( ppt), and ph of 8.3. Last year salinity was extremely high at over 43 ppt, dissolved oxygen was very low at 2.5 mg/l, and water temperature was lower at 22.8 ºC. Goleta Slough: greater surface area and depth make drought effects less noticeable than many smaller sites. Extensive algae beds (below). This fall, 3 BMI taxa, Amphipoda (Corophiidae), Ostracoda, and Polychaeta were observed in significant numbers, and BMI density was 417/ m 2 in Goleta Slough, compared to 4 taxa and 1,923/ m 2 last year. BMI composition was similar last year, but Corixidae were also present. Southern Coastal Santa Barbara Streams and Estuaries Bioassessment Program Page 51

52 Tecolote Creek Estuary Tecolote Creek estuary (MOD DIST) has an upstream watershed of approximately 3,700 acres, with land cover of approximately 75% wilderness, 2% herbaceous, 19% agriculture (mainly orchards), and 4% urban development. The estuary is long and narrow, extending north to south approximately 500 feet in length, with a width of 20 to 40 feet. The estuary was closed from the ocean by an approximately 50 feet wide sand berm at the time of the September 18 survey during mid tide conditions. Water levels were noticeably lower (2 maximum depth) than previous years due to the drought. Bottom substrate was mostly sand, with some gravel and cobble near the mouth. There was a thin surface layer of fine sediment and organic detritus and scattered clumps of submerged algae, grass, and organic litter. The area surrounding the estuary has been restored and preserved as a natural habitat area, which was presumably a condition of developing the Baccara Resort to the west. Thick riparian scrub and coastal scrub habitat with approximately 90 percent native cover and a width of about 300 feet borders both west and east sides of the estuary. Unpaved trails extend through the habitat area to the beach and a clubhouse that is part of the Baccara Resort. A footbridge crosses the estuary at its upstream end. Overall, human traffic and noise are light to moderate. Habitat assessment score was 75/100. Water and BMI sampling was completed at the downstream end of the estuary. Water chemistry readings were uniform with depth, with water temperature of ºC, dissolved oxygen of 11.2 mg/l, salinity of 2.0 ppt and ph of 8.2. Tecolote Estuary: water level lower than previous years (2 max. depth), surrounded by thick cattail/tule beds. This year 10 BMI taxa were observed at the estuary, and BMI density was 229/m 2, compared to 5 BMI taxa and 79/m 2 last year. The most abundant taxa were Ostracoda and Chironomidae, while Gammaridae, Coenagrionidae, Hydrophilidae, Dolichopodidae and Gastropoda were also found in significant numbers. Southern Coastal Santa Barbara Streams and Estuaries Bioassessment Program Page 52

53 Bell Canyon Estuary Bell Canyon estuary (MOD DIST) has an upstream watershed of approximately 3,900 acres, with land cover of approximately 75% wilderness, 6% herbaceous, 14% agriculture (mainly orchards), and 5% urban development. Bell Canyon estuary is about ¼-mile east of the Tecolote estuary, both having very similar watershed size and land use patterns. Bell Canyon estuary was closed from the ocean by an approximately 100 feet wide sand berm at the time of the September 18 survey during mid tide conditions. Water levels were very low with approximately 200 length, width, and only 0.5 maximum depth. Bottom substrate was mostly sand with a thin surface layer of fine sediment and organic detritus and scattered clumps of submerged algae and organic litter. The estuary is bordered by natural areas immediately to the west and north, the Sandpiper Golf Course to the east, and an oil and gas plant is situated further north. Fringing vegetation is approximately 60% native (e.g., tule beds, riparian scrub) and 40% non-native (e.g., ornamental trees and shrubs). Human traffic and noise are moderate. Habitat assessment score was 70/100. Water and BMI sampling was completed at the downstream end of the estuary. Water chemistry readings were uniform with depth, with very high water temperature (30.4 ºC) and dissolved oxygen (15.1 mg/l), ph of 8.2, and salinity of 4.1 ppt and ph of 8.2. Salinity was very high last year at 31.5 ppt. Bell Estuary: Surface area greatly reduced, maximum depth less than 1 due to drought. Area shown in bottom photo was completely inundated last year. This year 6 BMI taxa were observed at Bell Canyon estuary, and BMI density was 556/m 2, compared to 4 BMI taxa and 3,000/m 2 last year. The most abundant taxa this year was Ostracoda, which made up almost 80% of the BMIs sampled. BMI composition was very similar last year, which is interesting given the dramatic drop in salinity. Southern Coastal Santa Barbara Streams and Estuaries Bioassessment Program Page 53

54 Gaviota Creek Estuary Gaviota Creek estuary (REF) has an upstream watershed of approximately 12,900 acres, with land cover of approximately 60% wilderness, 39% herbaceous open space (grazed annual grasslands), and 1% urban development, consisting mostly of roads and park/campground facilities. The estuary is long and narrow, extending north to south approximately 1,500 in length, with a width of approximately in the upper estuary to approximately nearer the ocean. The estuary was closed from the ocean by an approximately 100 wide sand berm at the time of Gaviota Estuary: surface area and the September 18 survey during high tide depth reduced, note watermarks on conditions. Surface area and depth (2 maximum) bridge abutments (below). were lower than in previous years due to the drought. In the lower portion of the estuary, bottom substrate was mostly sand with a thin surface layer of fine sediment and organic detritus. Submerged grass beds were very thick throughout the majority of the lower estuary. In the upper estuary, substrate was mostly clay and fine sediments, with near vertical clay/soil banks of approximately 6 in height. The estuary is bordered by natural cliffs and coastal/riparian scrub habitat to the east, and the Gaviota State Park parking lot to the west. A coastal scrub/riparian habitat area wide serves as a buffer between the parking lot and the estuary. Native plants compose approximately 80% of the vegetative cover surrounding the estuary. Overall, human traffic and noise are light to moderate. Habitat assessment score was 90/100. Water and BMI sampling was completed at the downstream end of the estuary. Water chemistry readings were uniform with depth, with low water temperature (17.3 ºC), optimal dissolved oxygen (7.2 mg/l), high ph (9.3), and moderate salinity ( ppt). Salinity has been moderate to high (6-21 ppt) in this portion of the estuary in previous years. 5 different BMI taxa were observed at the Gaviota Creek estuary, and BMI density was 789/m 2. Isopoda and Ostracoda were the dominant taxa, and Gammaridae were also found in significant numbers. Last year, 7 taxa were observed and BMI density was 3,000/ m 2. Southern Coastal Santa Barbara Streams and Estuaries Bioassessment Program Page 54

55 Jalama Creek Estuary Jalama Creek estuary (REF) has an upstream watershed of approximately 16,000 acres, with land cover of approximately 75% wilderness, 20% herbaceous (grazed annual grasslands), and 5% agriculture. There is a small amount of urbanized development in the form of Jalama Road, the County campground (25 acres) and a few scattered ranch houses. Amongst the study estuaries, Jalama has the least disturbed watershed. The estuary is long and narrow, extending north to south approximately 1,000 in length, with a width of feet. The estuary was closed to the ocean at the time of the September 18 survey by a 50 -wide beach berm during high tide conditions. Surface area and depth (3 maximum) were reduced due to the drought. In the lower portion of the estuary, bottom substrate was mostly sand with a thin surface layer of fine sediment and organic detritus, and scattered clumps of submerged algae, grasses, and organic litter. In the upper estuary, substrate was mostly sand bottom flanked by soil and bedrock banks of approximately 5-15 in height. Thick beds of emergent tules and cattails extended from the banks out into the water. The estuary is bordered by natural hills and riparian scrub habitat to the west and Jalama Beach Park to the east. Sand dunes and vegetation provide a buffer of wide between the estuary and beach park. Native plants compose approximately 80% of the vegetative cover surrounding the estuary. Overall, human traffic and noise are light to moderate at the estuary. Habitat assessment score was 90/100. Jalama Estuary: Mostly native surrounding vegetation, shallow depth near closed mouth, algae prominent in this low salinity estuary. Water and BMI sampling was completed at the downstream end of the estuary. Water chemistry readings were fairly uniform with depth, with moderate water temperature ( ºC), optimal dissolved oxygen (11.3 mg/l) and ph (8.2), and low salinity (1.2 ppt). Salinity has been similarly low in previous years. 10 BMI taxa were observed at the Jalama Creek estuary, and BMI density was at 2,143/m 2. Baetidae was the dominant taxa, while Corixidae, Gastropoda, and Chironomidae were common. BMI density and composition were similar last year. Two sensitive aquatic vertebrate species, California red-legged frog and southwestern pond turtle have been observed at the Southern Coastal Santa Barbara Streams and Estuaries Bioassessment Program Page 55