Shrimp is one of the most valuable and plentiful commercial fisheries in Louisiana, but locating aggregations of shrimp in numbers high enough to harvest takes a lot of effort. New research findings could help change that, making it easier for shrimpers to find shrimp.
The study’s findings describe how dissolved oxygen and other environmental factors affect the spatial distributions of brown and white shrimp off the coast of Louisiana.
Excess nutrients from the Mississippi River stimulate an overgrowth of algae in the Gulf of America. When these algae die and decompose, they deplete oxygen in the water as they sink to the bottom. The resulting low oxygen levels (hypoxia) cause animals, like fish and shrimp, to leave the area.
Using more than 30 years of fishery-independent trawl survey data (1987–2017), the researchers developed models to quantify the impacts of hypoxia in combination with other factors, including sediment composition and fishing effort. The data show significant shifts in habitat use in response to severe hypoxia. Notably, brown and white shrimp occurred further offshore in deeper waters, but were also highly concentrated in nearshore waters, landward of the hypoxic zone (Figure 1).
The findings also show that both shrimp species are frequently found in areas with “moderately low” oxygen, suggesting that part of Louisiana’s shrimp population may be experiencing chronic physiological stress. Lab evidence has shown that shrimp subjected to comparable levels of dissolved oxygen experience increased respiration rates and decreased feeding, which can impact shrimp survival and productivity.
The models developed for the study could be combined with existing hypoxia forecasting models to create seasonal predictions of shrimp distributions, which would promote better fisheries management and a more resilient coastal economy.
The project was authorized by the Harmful Algal Bloom and Hypoxia Research and Control Act (HABHRCA) 33 U.S.C. §§ 4001 et seq.
Citation: Alexey Katin, J. Kevin Craig, Daniel R. Obenour. A flexible modeling approach for evaluating the effects of hypoxia and other factors on the spatial distributions of brown shrimp Farfantepenaeus aztecus and white shrimp Litopenaeus setiferus on the Louisiana shelf. Marine and Coastal Fisheries, Volume 17, Issue 6, Nov. 2025, https://doi.org/10.1093/mcfafs/vtaf038
