The Localized Source of Enterococci at Pier 19

Transcription

1 The Localized Source of Enterococci at Pier 19 FINAL REPORT Submitted: August 10, 2018 Prepared by: Tino Quiocho Prepared for: 1100 Hercules Avenue, Suite 200 Houston, TX Project Pier 19 Final Report 1

2 Table of Contents Introduction... 3 Methodology... 4 Materials... 4 Overall Site Summary... 5 Site Visit Observation... 6 Results... 9 Geometric Mean Site View...10 Conclusion...11 References...11 Acknowledgements...12 Project Pier 19 Final Report 2

3 Introduction Enterococci are a group of indicator bacteria that demonstrate the presence or absence of fecal matter in the water. Naturally, they occur in the intestines of warm blooded animals. EPA primary recreation standards for enterococci levels in a body of water are a single grab of >130 Most Probable Number (MPN) or a geometric mean of >35 MPN. (TCEQ p.47) In humans, pathogens found in fecal matter can cause sicknesses including inflammation on points of contact, blood infection, and infectious respiratory and enteric diseases. On an economic level, multidrug-resistant Enterococcus strains have been leading causes of hospitalacquired infections with an estimated 800,000 cases of enterococcal infection in the US each year, adding $500,000,000 to annual healthcare cost. Additionally, fecal contamination can affect healthy oyster populations and make them too dangerous to harvest and consume. Enterococci groups are persistent in the environment and ubiquitous in warm blooded animal feces. For these specific reasons, they serve as a beneficial indicator species. (Boehm, 2014) Wildlife, rainwater runoff, sanitary sewer overflows, and vessel discharge are some of the non-point sources of fecal bacteria in Galveston Bay. These various sources, along with salinity, water temperature, and light intensity, cause spikes in fecal indicator bacteria levels. (GBF 2017) The Galveston Bay Foundation (GBF) citizen science water monitoring team samples sites around Galveston Bay each month for general water quality parameters with about half of the locations also being sampled for enterococci. One of GBF s sites, Pier 19, has recently shown high levels of enterococci. The Bacteria Action Limit Protocol states that if the sample exceeds 520 MPN, or 312 MPN when there has been no rainfall, then within a 72-hour period the volunteer (or a GBF trained staff member) is supposed to resample. If resampling reveals concentrations still above that value at least three days after initial sampling, then the GBF staff notifies the proper authority. Additionally, a site visit and targeted sampling is conducted to determine the extent and potential source of the pollution. Pier 19 presented exceeding levels for more than three days after the initial sample. The Water Quality Team investigated the site sampling 6 additional spots around the area to determine the following: first if the problem was isolated and second, if there were any potential sources of pollution. After one day of sampling and investigation, they concluded that the problem was isolated within the marina and that the Project Pier 19 Final Report 3

4 presence of birds was likely influencing this influx of enterococci bacteria. However, additional sampling was deemed necessary to confirm this conclusion and better identify potential sources. The purpose of this research project is to continue investigations at Pier 19 to determine whether our data analysis and conclusions are either backed up with a sufficient amount of evidence or to find another factor causing spikes of potential fecal matter in the area. Methodology The first step of this project was to observe the Pier 19 site in Galveston while collecting samples for bacteria testing at 5 different spots around the pier. Once a week, bacteria samples were collected in the morning and then processed in the lab in the afternoon. This routine took place over a 6-week period during June and July 2018, in order to collect a sufficient amount of data to support or reject our Water Quality Team s previous conclusion. If the opportunity presented itself, we sampled after any major rain event resulting in more than 0.5 of rainfall to capture the impacts runoff was having. Runoff shows us how much fecal waste on the land would be affecting the water surrounding the site. It was important to test after both rain and dry events, so we could see if the problem was caused solely by runoff. Additionally, a bird activity analysis was conducted since the team s initial conclusion for the high enterococci levels was from bird defecation. We looked at the types of birds present, and how much defecation on the pier existed before and after rain events. Finally, during our site visits, we had open discussions with the public to gauge their overall opinions, knowledge, and thoughts of the water quality in this area. Materials At each site dissolved oxygen, salinity, and temperature were measured in the field using the YSI Pro meter. The ph was also measured using LaMotte ph test kits per the Texas Stream Team Water Quality Testing Methods. Bacteria samples were taken for analysis using IDEXX ENTolert at the GBF Bacteria Lab, and MPN was reported for each sample. Three-day rainfall amounts were also collected and recorded from Harris County Flood Control District. All data analysis was completed using the Microsoft Excel data analysis package. Project Pier 19 Final Report 4

5 Overall Site Summary Figure 1. A map of the sites visited for Project Pier 19 Site 81042, as shown in Figure 1, consists of Pier 19 and is located off Harborside Dr. on Galveston Island and leads to the Galveston Channel. The West end of the pier is wider and made of concrete while the East end of the pier is made of wood and serves as the boat dock. Directly South of this pier are restaurants and places that sell fresh seafood produce. Site 1 is located within the marina at the end of Pier 21, where the small dock is dedicated to Touring Boats. Site 2 is close to the entrance of the Ocean Star Offshore Drilling Rig and Museum and the sample is gathered from the channel. Site 3 is located at the beginning of the Pier s boat dock while Site 4 is at Dock 23 near the end of the Pier across from the museum. Site 5 is located off Wharf Road just to the east of Katie s Seafood Market where an outfall is located. Project Pier 19 Final Report 5

6 Site Visit Observations Site 1: During the first site visit on June 21 st, tour boats were very active coming in and out of marina while picking up and dropping off passengers. Not a lot of bird activity around this site. On June 28 th, there were tour boats taking people to and from the dock near Site 1. The sample was taken before any boats left so Dissolved Oxygen (DO) was not high. Just a couple of gulls and pelicans flying around the Tour Boats as they came and left. On July 5 th again, the sample was taken right before the tour boats left so that DO was not high. Unfortunately, there is no knowledge of boats entering the site right before the sample was taken. On July 11 th, it seemed arriving around 10:00am the tour boats do not leave for another tour until around 10:15am. They have two boats so when one leaves, another comes back and loads up with people. Not really a lot of birds near this site. On July 18 th, there were pelicans and laughing gulls very high up in the sky. Touring boat left 5 minutes before the arrival time. On July 26 th, there were not any tour boats while at Site 1. A lot of trash in the water along with debris. Around 5-10 laughing gulls there. Site 2: On June 21 st, there were clouds out so no need for shade. Mostly laughing gulls flying around my site but there are some pelicans (in three s) in the distance. On June 28 th, a lot of boats passing by from the channel, but the DO is still similar to the first site. Also 3 jellyfish were spotted. On July 5 th, there were 3 boats that passed by possibly increasing the DO. The bird count at the site was 4 pelicans and 3 laughing gulls. Project Pier 19 Final Report 6

7 On July 11 th, another 3 boats passed along. A lot of laughing gulls and 1 brown pelican. On July 18 th, it was cloudy, so shade was provided at this site. The birds again were laughing gulls and there was a lot of bird defecation on the pier. Only one boat passed by that day. On July 26 th, the most bird defecation on the pier that has been seen. 20+ laughing gulls at this site. Site 3: On June 21 st, there were a lot of birds around this site most likely because there were boats they could scavenge for food. People going from pier to museum. On June 28 th, there was a lot of trash in the water near the site. Spotted cormorants on pilings under the new restaurant being built. On July 5 th, there were a couple of fisherman drop-offs with a lot of people working around the site. One small blackbird joined the sampling by the trash bins. On July 11 th, there were 2 shrimp boats that entered the marina. These were followed by 50+ laughing gulls, 20+ pelicans, and some of different shorebird species that were following the shrimp boats. On July 18 th, around 15 pelicans passed over the site in a V shape formation. By this time the clouds over the pier have moved on. On July 26 th, a shrimp boat came again bringing a lot of different shorebirds. Scum and a lot of bubbles on the water surface. Site 4: On June 21 st, not really, any activity from anyone around here. Most of the birds spotted at this site were on the rocks in front of the railings on the pier. On June 28 th, there were people fishing right passed the rocks where high levels of bacteria most likely are. Just large pelicans and cormorants on the rocks sunbathing. Project Pier 19 Final Report 7

8 On July 5 th, there were some boats passing by approximately 20 cormorants and 10 laughing gulls. On July 11 th, the laughing gulls were all resting on the railings of the pier with some pelicans and cormorants on the rocks. Just the couple of tour boats passed by in the channel. On July 18 th, the usual amount of laughing gulls, pelicans, and cormorants on the rocks and pier were at this site. 2 big boats passed by, but the second one after the sample was taken. On July 26 th, 2 big boats passed by in the channel. Very few birds at this site which is unusual. Site 5: On June 21 st, activity mainly from people with some birds flying over. Overall site feels dirty for some reason. On June 28 th, there was like dried grease and other nasty things all over the concrete at this site. Not really any birds around this site as well. On July 5 th, there was a kid urinating near the site before the sample was taken. Only a couple of pelicans near the site. On July 11 th, the site had a lot of scum on the top of water. The description of the smell was stale Cheetos. Not really any birds at this site again. On July 18 th, there was a man who mentioned that the outfall at site 5 stretches back to church and 19 th. Again, there were no birds near this site. On July 26 th, there were just people around Katie s Seafood Market and not as many birds as usual. Project Pier 19 Final Report 8

9 Results MPN vs Rainfall Per Week Bacteria Count (Most Probable Number) Week 1 Week 2 Week 3 Week 4 Week 5 Week 6 Site 1 Site 2 Site 3 Site 4 Site 5 Figure 2. A graph with the number of bacteria and rainfall that occurred at each site each week. Table 1 - Rainfall Per Week Inches of Rainfall Accumulation (Runoff) Days Since Last Precipitation 6/21/ /28/ /5/ /11/ /18/ /26/ Project Pier 19 Final Report 9

10 Geometric Mean Site View Figure 3. Geometric Means at each of Project Pier 19 sites Table 2 - Geometric Mean Per Week Week 1 Week 2 Week 3 Week 4 Week 5 Week 6 GeoMean GeoMean Parameters Site MPN Low (<14.9 MPN) Site MPN Site MPN Site MPN Site MPN Medium ( MPN) High (>35 MPN) Project Pier 19 Final Report 10

11 Conclusion Based on the observations and results gathered for Project Pier 19, the initial conclusion by the Water Quality Team was rejected. Figure 2 shows that rainfall amount is directly correlated to the number of bacteria and Site 3 and 5 were above the geometric mean parameters for recreational use as shown in Table 2. The source for the high levels of bacteria at Site 3 is non-point source of bird defecation. This is because the highest amount of bird activity was observed at this site and every week there was a rainfall event, this particular site s bacteria count would rise (see Figure 2). The reason we reject the Water Quality Team initial conclusion is because the bird defecation is not the only source affecting this pier. At Site 5, there were the least amount of birds recorded in the observations and according to Figure 2, Site 5 continually had the highest amounts of enterococci every week. Week 6 was the most interesting for this site since its second highest count of bacteria occurred when there were 0 inches of rainfall that week, with no precipitation for the previous 17 days. Finally, the results that ultimately reject the initial team s conclusion is that the outfall located at Site 5 is causing the high levels of bacteria for that site, and not the bird defecation. References Texas Commission on Environmental Quality. (2018). Texas Surface Water Quality Standards. sections_nopreamble.pdf Galveston Bay Foundation. (2017). Bacteria Reduction Plan. Boehm AB, Sassoubre LM. (2014). Enterococci as Indicators of Environmental Fecal Contamination. Project Pier 19 Final Report 11

12 Acknowledgements This research project is supported by the Gulf Research Program of the National Academies of Sciences, Engineering, and Medicine under award number A special thanks to everyone at Galveston Bay Foundation for making this effort possible and especially my mentor, Lindsey Nolan, from the Water Quality Monitoring Team, for proposing and guiding me throughout this project. Project Pier 19 Final Report 12