Science Serving Maryland's Coasts

R/P-62

Effects of Oyster Biodeposit Resuspension on Nutrient Release and Ecosystem Dynamics in Chesapeake Bay

Principal Investigator: 

Elka Porter

Start/End Year: 

2018 to 2020

Institution: 

University of Baltimore

Co-Principal investigator: 

Lawrence Sanford, Horn Point Laboratory, University of Maryland Center for Environmental Science

Strategic focus area: 

Healthy coastal ecosystems

Description: 

While existing research addresses many of the important issues of oysters in Chesapeake Bay (CB), the fate and effects of resuspended oyster biodeposits in aquaculture areas on the nutrient, light, zooplankton and phytoplankton dynamics have not been taken into account when the use of oysters in mitigation of eutrophication in CB is examined. Currently, models do not include the effects of biodeposit resuspension on the ecosystem, nutrient dynamics and light and experimental data are not available. We propose two 6-week long experiments in shear-turbulence-resuspension-mesocosm (STURM, R) systems versus nonresuspension (NR) systems to study the effect of biodeposit resuspension in high flow and low flow areas right next to and under mimicked aquaculture rafts on the nutrient dynamics (including denitrification), the ecosystem function, light and the nitrogen budget. This proposed study will help evaluate ecosystem services benefits of oysters important for oyster restoration and healthy ecosystems and may help the evaluation of the use of oysters as Best Management Practice (BMP) and the siting of oyster aquaculture. In our previous research on coupling between sediment resuspension and ecosystem processes, we have often found nonlinear, unexpected responses of both nutrient dynamics and ecosystem function. The Maryland Sea Grant supported Shear Turbulence Resuspension Mesocosm (STURM) facility designed by Porter and Sanford and located at the Patuxent Environmental and Aquatic Research Laboratory (PEARL) will be used for the experiments and is a one of a kind system that mimics high bottom shear stress due to tides and storms, realistic water column turbulence levels, and realistic benthic-planktonic interactions over extended periods. We will examine the effect of biodeposit resuspension right next to and under mimicked aquaculture rafts on nutrient regeneration and phytoplankton growth, effects on denitrification and the effect of oysters on water clarity, compared to mimicked low flow areas right outside and under aquaculture rafts. Moreover we will measure ecosystem variables such as zooplankton abundance and composition. Our data will be utilized by the CBP Oyster BMP expert panel, the Chesapeake Bay Foundation, Maryland DNR, NOAA, and the Oyster Recovery Partnership. We will provide an experiential learning experience to undergraduate students through internships.