Oyster larval transport/hydrodynamic modeling at Tangier/Pocomoke Sound, Virginia

Description

Background: The Chesapeake Bay Oyster Restoration Program will soon achieve the goal of successfully restoring oysters to 10 tributary rivers, 5 in Virginia and 5 in Maryland. This was the initial goal of the Chesapeake Bay Program’s Oyster Goal Implementation Team (GIT). Restoration efforts are now being moved to the more open waters of the Chesapeake Bay mainstem, Tangier and Pocomoke Sound on the east side of the Bay mainstem near the Virginia/Maryland Border. In the late 1800s, this area was surveyed and found to hold 2,252 HA of oyster reefs, a subsequent survey in the 1980s found only 630 HA of oyster reefs, a 72% loss (Schulte 2017). Due to the non-random distribution of oyster reefs in the region, it is highly likely that the local currents and their ability to transport oyster larvae has played a key role in where reefs have come to be established and maintained over time. It is known that most oyster reef systems consist of both source and sink reefs, with the source reefs providing oyster larvae to auto-recruit on themselves, as well as provide larvae to reefs that are not located in waters where they can be self-sustaining on their own (Lipcius et al. 2015, Theuerkauf et al. 2021). There are hopes to construct a large-scale oyster reef restoration effort in this region. During the planning process, sites need to be selected and prioritized based on the benefits they can provide. Simulations from bio-physical models can be used to identify potential restoration sites based on how they fit in to the regional metapopulation. The hope of this work is to be able to utilize the information to select sites with the greatest potential to enhance the overall recruitment in the region. Brief Description of Anticipated Work: What are our objectives? We would like to assess the oyster larval transport dynamics of the Tangier/Pocomoke Sound region. We would like to identify source and sink areas for the regional oyster metapopulation to help us locate oyster reefs for maximum population enhancement benefits. We are interested in estimating the oyster population size that would enable a detectable regional benefit to oyster recruitment. Estimating the necessary oyster population to influence recruitment at a detectable level has, to our knowledge, never been done. The region is large and fairly open, however it is expected that due to the non-random locations of historical reefs, there are favorable currents in some areas conducive to oyster larval settlement.

Agency Contact

More from Engineer Research and Development Center