Developing nitrogen bioextraction economic value via off-bottom oyster aquaculture in the northwestern Gulf of Mexico.

Eutrophication remains a persistent water quality issue throughout much of the United States, leading to changes to ecosystem health in valuable coastal habitats. Oysters help to buffer against eutrophication by removing nitrogen from the water column by feeding on phytoplankton and other seston, a process referred to as "bioextraction". Recent legislation in Texas has allowed oysters to be grown off-bottom (suspended in cages). To understand the connections between bioextraction and off-bottom oyster aquaculture, the Assessment of Estuarine Trophic Status (ASSETS) model was applied, indicating nutrient-related degradation of water quality. The Farm Aquaculture Resource Model (FARM) was used to determine that a typical oyster farm can remove about 4900-7100 lb. N yr, with an approximate value of $41,966 to $232,511 based on engineered (wastewater treatment plant) technologies. A promising and innovative nutrient management strategy, bivalve mariculture can be utilized as an additional strategy complementary to existing nutrient management strategies.