Nearshore Benthic Habitats Program

Transcription

1 Nearshore Benthic Habitats Program Travis Thyberg, Diego Lirman, Greg Deangelo, Joe Serafy, Sarah Bellmund, Ligia Collado, Joan Browder Rosenstiel School of Marine & Atmospheric Science University of Miami NOAA / National Geodetic Survey NOAA / National Marine Fisheries Service Biscayne National Park Florida International University

2 What? Where? When? SAV abundance, diversity, distribution Matheson Hammock to Manatee Bay, < 1000 m from shore Dry Season, Wet Season How Long? 2003, 2005, 2008, 2009, 2010-?? Why? How? Nearshore Habitats and SAV are Restoration Targets Photographic and Visual Surveys, Tissue Collections

3 Why monitor nearshore benthic habitats?? These habitats have been under-represented in monitoring efforts due to limited boat access ( < 1m in depth ) Critical nursery habitats Their location makes them susceptible to changes in freshwater deliveries These habitats are explicit CERP Restoration Targets CERP SAV Restoration Goals for Southern Biscayne Bay: 1) increase cover of seagrass, primarily Halodule and Ruppia, in nearshore areas; 2) Reduce dominance of Thalassia 3) increase the abundance and diversity of fish and macroinvertebrates associated with SAV.

4 Nearshore Benthic Habitats Program: Core Components 1. GeoSpatial SAV surveys (Shallow Water Positioning System, SWaPS) Large-scale (Matheson Hammock Manatee Bay) Seasonal Surveys (Dry Season, Wet Season) Stratified Random Site Selection (5 buffers, 4 zones) Inshore-Offshore Continuous Transects Products: Spatially and seasonally resolved patterns of SAV abundance, distribution, and diversity Geo-tagged High-resolution digital images of the benthos WQ parameters at each survey site (WQ-SAV correlations) SWaPS website:

5 Nearshore Benthic Habitats Program: Value Added Components Projects: a) High Frequency SAV surveys (focus on Macroalgae) Bi-monthly surveys and tissue collections (Black Point, Deering Estate) b) SAV surveys at BISC s WQ permanent sites c) SAV surveys at Browder (epibenthic) and Serafy (mangrove fish) sites d) Remote Sensing of SAV communities

6 CHANGE INDICATORS Macroalgal abundance, diversity, distribution, morphometrics Epiphyte Community (encrusting, filamentous, bacterial) Seagrass abundance, diversity, distribution, morphometrics Landscape Structure and connectivity, Weeks Months Years Years - Decades

7 Survey Methodology : SWaPS

8 Matheson Survey Area / Design 4 survey regions (salinity, hydrodynamics) 5 cross-shelf buffers (100 m) Black Pt Turkey Pt Manatee Bay Card Sound Barnes Sound

9 Geo-tagged Images Scored to assess percent cover of SAV

10 SAV Cover Mean % Cover Macroalgae Thalassia Halodule Syringodium 0 Dry 2003 Dry 2005 Wet 2005 Dry 2008 Wet 2008 Dry 2009 Wet 2009 Dry 2010 Decline in Tt Stability of Hw, Sf MA highly dynamic (good indicator)

11 SEAGRASS DISTRIBUTION. CANAL INFLUENCES % cover % cover Max Max Min Min Seagrass distribution related to freshwater discharges

12 Seagrass-Salinity Relationships 1.00 Probability of Occurrence (p) Mean Salinity (psu) Thalassia Halodule Syringodium Seagrasses are good indicators of salinity changes at annual scales

13 CHANGE INDICATORS Macroalgal abundance, diversity, distribution, morphometrics Epiphyte Community (encrusting, filamentous, bacterial) Seagrass abundance, diversity, distribution, morphometrics Landscape Structure and connectivity, Weeks Months Years Years - Decades

14 Macroalgae are key components of SAV communities

15 Salinity Patterns in Black Point Salinity (psu) 35 N of Jetty S of Jetty Distinct Salinity Patterns on different sides of the Jetty Mar Apr May Jun Jul Aug Sep Oct Nov Dec Lower salinity S of the jetty

16 Macroalgae of Black Point Distinct Macroalgal Communities on different sides of the Jetty 20 Similarity Estuarine Group: Chara, Acetabularia, Batophora Transitional Group: Laurencia, Penicillus, Palisada Marine Group: Anadyomene, Halimeda Macroalgae are a good, dynamic indicator of salinity patterns!

17 CHANGE INDICATORS Macroalgal abundance, diversity, distribution, morphometrics Epiphyte Community (encrusting, filamentous, bacterial) Seagrass abundance, diversity, distribution, morphometrics Landscape Structure and connectivity, Weeks Months Years Years - Decades

18 Landscape SAV Indicators of Salinity Patterns Goal: Explore patterns of habitat structure (patchiness, fragmentation) in relation to WQ patterns Aerial Image Classified Image

19 Seagrass landscapes can be divided into fragmented and continuous SAV habitats Fragmented SAV habitats have higher density of small SAV patches and more complex shapes than continuous SAV habitats

20 Fragmented SAV landscapes are found in areas influenced by freshwater deliveries Continuous SAV landscapes are found in areas with high and constant salinity, removed from freshwater canals Pulsed release of freshwater creates landscapelevel fragmentation of SAV habitats!!! Fragmented habitats have been shown to be more prone to mortality and may have lower habitat value for associated species.

21 Nearshore Benthic Habitats Program: Summary SAV (seagrasses and macroalgae) components are good indicators of salinity patterns (e.g., distribution presently influenced by salinity regime) Seagrasses are the principal component of the nearshore SAV community during the Dry season (mean cover = 25.5 %), while macroalgae dominate during the Wet season (33.4 %). The distribution and abundance of SAV are directly related to the tolerance of each taxon to salinity patterns. Need a nested suite of indicators that work at different spatial and temporal scales Provide direct input into modeling efforts Need to establish a long-term baseline comparable to that of other components

22 ACNOWLEDGEMENTS Funding National Geodetic Survey DOI NPS CESI Program NOAA NMFS CERP RECOVER Program US ACoE NGS Gerry Mader NOAA Erick Buck Tom Jackson NPS Richard Curry Lirman Lab James Herlan Britt Huntington Steph Schopmeyer Caitlin Hill Ford Drury