City of New York Parks & Recreation RESTORING THE EASTERN OYSTER (Crassostrea virginica) IN AN URBAN Natural Resources Group Michael R. Bloomberg, Mayor Adrian Benepe, Commissioner Bill Tai, Director, Natural Resources Group ESTUARY: A COMMUNITY EFFORT ON THE BRONX RIVER, NY ` Allison Mass1,2, Victoria Ruzicka1, and Janine Harris1 1New York City Department of Parks & Recreation Natural Resources Group (NRG) 1234 Fifth Ave. New York, NY 10029 2 The Graduate Center, City University of New York, 365 Fifth Ave, New York, NY 10016 OVERVIEW REEF MONITORING: RESULTS & DISCUSSION COMMUNITY PARTICIPATION Introduction: Changes in the Benthic Invertebrate Community over time: Total Volunteer Hours by Activity This project was funded as a Community Eastern oysters (Crassostrea virginica) were once plentiful in the New York/New Jersey Harbor, but due to disease, over harvesting and 2006‐2008 The reef structures may have had an impact on the benthic invertebrate community Collaborative Project. Partners involved in poor water quality, the population declined to nearly zero in the early 1900s. By the late 1920s the State Conservation Department Activity over time, by reducing the amount of oxygen that can penetrate to the infaunal project planning, site visits, pilot reef placement, closed New York City’s waters to shellfishing entirely. Even without ongoing harvesting, oyster populations remained low due to 8% Molluscs and Annelids at the 2006 REEF site. The 2007 REEF site was constructed Reef Preparation & Placement environmental education and monitoring include habitat degradation, sedimentation and pollution (1). Oysters are still located in small, discrete populations around the harbor today, (985 Hours) differently, and this may have allowed for more oxygen to penetrate the sediments Rocking the Boat (RTB), Youth Ministries for including along the shoreline of the Bronx River at Soundview Park in the Bronx (Figure 1). Through funding from José E. Serrano Monitoring (634 Hours) and more organisms to continue to live underneath the reef structure. Lack of 23% 42% Peace and Justice (YMPJ), The Bronx River WCS-NOAA Lower Bronx River Partnership, the New York City Department of Parks & Recreation, Natural Resources Group oxygen can lead to a decrease in abundance and biodiversity of benthic invertebrates, Alliance (BxRA), Sustainable South Bronx (NRG) began evaluating this site in 2004 to identify restoration opportunities for this small population of oysters. These initial efforts Oyster Garden (544 Hours) with slow recovery (2,3). The decrease in Annelids at the REFERENCE site can be (SSB), Lehman College, and GreenApple led to the placement of two pilot oyster reefs at the project site. Educational (172 Hours) The goals for this project were: in indicator of other extraneous factors, such as pollution, which are impacting Corps. From 2006-2008, over 100 different 27% •To increase fish and shellfish habitat in the benthic species diversity (4,5,6)(Figure 2a-c). students and community members participated lower Bronx River by creating new habitat in this project on various activities, completing 2335 hours of work (Figure 6). structure on the existing landscape. Figure 6: Division of labor amongst volunteers, 2006-2008. •To restore subtidal diversity to the Bronx River Rocking the Boat: Estuary by increasing the sustainable oyster Rocking the Boat (RTB), a boat building and environmental education program for high school students in the populations which serve as habitat for a variety South Bronx, is the most active partner on all aspects of this restoration project. Since 2006, RTB students and of organisms. staff have completed 1597 hours of work towards this restoration effort. RTB played an integral part in reef •To improve water quality in the Bronx River preparation and placement, providing the manpower that was necessary for successfully completing this Estuary by increasing the sustainable oyster activity. RTB students and staff have also dedicated many hours in the field to reef monitoring and oyster populations which have a high water filtering gardening. capacity. During August 2006, NRG created a survey aimed at gauging how the project impacted the actions, interests, •To increase education and stewardship and opinions of 22 students involved in the restoration program: opportunities for local environmental groups by •100% of the students agreed that they can explain to others why the oyster reef is important for the Bronx including these groups in project planning, reef River. Figure 1: Project location along the shore of Soundview placement and monitoring efforts. Figure 2a-c: Species Abundance and Diversity at the 2006 REEF (2-a), 2007 REEF (2-b), •86% of the students agreed that they and other volunteers have made a difference with the oyster Park at the confluence of the Bronx and East River. and REFERENCE (2-c) sites at Soundview Park restoration project. In order to accomplish these goals, NRG worked with local scientists and community groups to collect biological, geological, and •50% of the students talk about the project with their families and neighbors. water quality data at the reef sites. In turn, this data was used to determine the overall success of the project and the project design. The results from these monitoring efforts are being shared with New York City practitioners looking at the larger picture of restoring Oyster Spat: oysters to the New York/New Jersey Harbor. The average size of oyster spat was positively correlated with time during 2008 Constructing the Pilot Oyster Reefs: and 2007 monitoring (Figure 3). The loose shell construction of the monitoring baskets on the 2007 REEF may have been more attractive to settling oysters, due The first pilot reef (“2006 REEF”) was placed at Soundview to the larger spaces between shells (7,8); on the 2006 REEF, more oyster spat were Park in July 2006. Bags of surf clam shell were arranged in a found in the monitoring bags that were less tightly packed. The total number of 15m2 plot. Several plastic trays, each containing two bags of spat found in 2008 was less than 2007, however, misidentification of Slipper shell, were placed within the bottom layer of the reef for snails (Crepidula plana)asCrassostrea virginica during the 2007 field season monitoring purposes. A second pilot reef (“2007 REEF”) of may have lead to an overestimate of oyster spat. the same size was placed in June 2007, 50 meters north of the 2006 REEF site. The 2007 REEF is designed differently; it Oyster Gardens: has a border of plastic mesh bags containing surf clam shell, Local volunteer groups have adopted oyster “gardens” since learning about oysters during this project. Volunteers check the oyster and the interior is filled with loose shell. Monitoring trays Figure 3: Average size of oyster spat at Soundview Park . gardens once a month for growth and mortality. After 1 year, oysters are transferred to a “retirement” area on the 2007 REEF at were placed in the center of the reef and were filled with Soundview Park, where they are monitored for growth and survival once a year. The growth data and water quality measurements at the loose shell instead of bagged shell. garden sites have provided NRG with valuable data about the ability of oysters to survive at future restoration sites. In addition, this restoration effort has taught students and volunteers about the Bronx River ecosystem and scientific monitoring skills. Oyster spat Sediment Deposition over time: PROJECT SUMMARY & FUTURE GOALS The reef structures had an impact on deposition rates over time, as the REEF sites have 40-50% higher deposition rates than the REFERENCE site. Increased The Pilot Oyster Reef project at Soundview Park has been a success for both the Bronx deposition rates on the reef may reduce the settlement of future oyster larvae by River ecosystem and surrounding South Bronx community. Creating reef habitat in the obscuring shell surfaces and possibly smothering existing oyster spat, which can Bronx River estuary has increased biological diversity within the reef area and encouraged lead to reduced growth and increased mortality (9)(Figure 4). Different protocols oyster spat settlement. Just as importantly, this project has successfully incorporated local each year may have skewed the data, but also natural phenomena such as weather community groups into project planning, preparation, and data collection. Several students patterns, algal blooms, and increased eutrophication may have lead to an increase with volunteer groups have earned various scholarships and stipends based on essays Figure 4: Sediment deposition rates at Soundview Park (2006-2008). in sedimentation in the Bronx River Estuary (10). written about their time with the Pilot Oyster Reefs. This project has succeeded in Fish and Crustacean usage of the reefs: educating the community about the importance of watershed health, the function of reef ecosystems, and the importance of Bronx River stewardship. Local community groups Fish seining occurred in 2007 and 2008, although weather problems limited the amount of seines in 2008 (12 vs. 36). There was a decline in now have the skills necessary to undertake their own restoration sites in the Bronx River, species diversity on all sites from 2007-2008, but an increase in the abundance of the dominant species. These species, which commonly use and will begin project planning for a new reef in 2009. oyster reefs for reproduction and refuge from predators, include Winter Flounder Pseudoplueornectes americanus, Northern Pipefish, Syngnathus fuscus, and Blue Crab Callinectes sapidus (11,12)(Figure 5a-b). Declines in species biodiversity from 2007 to 2008 are most The grant for this project will end December 2008. Plans are currently under way to likely due to sampling error (open nets and few replicates) that occurred in 2008. extend the grant for an additional year in order to build a third reef to create more oyster habitat. The design of the third reef will be based on the design successes and failures learned during the past 3 years.