Our research is the first to investigate hypoxia’s effects on the harvest and economic dynamics of a Gulf of Mexico shrimp fishery. By linking hypoxia to impacts on fisheries, we hope to link the interests of those charged with managing the nutrient load to coastal watersheds and those charged with managing coastal fishery resources. It will also provide a quantitative means to evaluate the 2008 Action Plan goal of reducing the spatial extent of hypoxia in the northwest Gulf of Mexico.
Why We Care
In the summer, seasonal hypoxia occurs in the northwest Gulf of Mexico (nGOM) as commercial shrimpers resume harvesting operations. But hypoxia’s effects on the harvest and economic dynamics are largely unknown. To operate one of the country’s most valuable single-species fisheries, managers must understand how hypoxia is impacting the ecosystem’s ability to support brown shrimp. On the Louisiana shelf, hypoxia-induced habitat loss has decreased the range of brown shrimp by 25% since the early 1980s. In large areas of the shelf where hypoxia is most severe, shrimp move both inshore and offshore.
What We’re Doing
Evidence indicates that hypoxia alters harvest dynamics and decreases profits in the shrimp industry by reducing the available habitat of brown shrimp in nGOM’s dead zone. Moreover, hypoxia can change biological production that determines the amount of a targeted shrimp species potentially available for harvest. It can also change the fishery sector itself through fishing behaviors and practices.
We’re combining retrospective analyses (historical data sets, targeted field efforts, econometric modeling, and quantitative policy evaluations) to determine the full scope of hypoxia’s effects on the shrimp fishery. The coupling of human and natural systems is an important step toward more integrated and ecosystem-based management approaches that link watersheds to coastal systems and fisheries.
Our objectives are to:
- Evaluate the effects of hypoxia on the spatial and temporal dynamics of shrimping and the catch to quantitatively model the fishery and inform fishery managers
- Determine the spatial extent and nature of hypoxia effects on the spatial behavior and fishing activities of individual shrimp vessels
- Quantify the economic consequences on the fishery using discrete choice models of shrimping behavior
- Identify the economic impacts of hypoxia using quasi-experimental methods
- Develop a bioeconomic model of the shrimp fishery that can be used to assess the economic consequences of alternative nutrient and fishery management policies.
Our work is part of the Gulf of Mexico Ecosystems & Hypoxia Assessment (NGOMEX) program. The project team is led by Dr. Kevin Craig of NOAA Fisheries with co-investigators from Duke University and NCCOS.
What We’re Finding
This work is allowing managers to evaluate the likely impacts of eutrophication and hypoxia on fisheries, the practices of fishermen, the associated economic costs of habitat degradation, and the benefits of environmental policies to reduce nutrient pollution.