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A new North Carolina Sea Grant study shows that combining shrimpers’ local knowledge with traditional science leads to a clearer picture of why shrimp populations fluctuate. 

Shrimp play a crucial role in North Carolina estuarine and oceanic food webs and as one of the state’s most valuable fisheries. Commercial harvests include brown, white, and pink shrimp, and the catch rates of all three species can vary widely from year to year as a result of changes in the numbers and locations of the three populations.

Our research team at East Carolina University’s Coastal Studies Institute recently used more than 30 years of data from the NC Division of Marine Fisheries’ trawl survey in Pamlico Sound to understand whether environmental changes were linked to changes in shrimp populations. Our models performed incredibly well, and for brown and white shrimp — the most commercially important of the three species — the models could predict at least 75% of the variability in the populations by incorporating factors like salinity, temperature, wind speed and direction, and the abundance of spawning adult shrimp.

Local Shrimpers and What They Know

This led our team to a new question: Could we learn even more by also incorporating fishers’ knowledge of which environmental conditions influence shrimp populations? We combined ecological models and a survey of commercial shrimp fishers to study the influence of storms, wind, rainfall, temperature, and offshore reproduction on the abundance of white and brown shrimp in Pamlico Sound.

Storms, rainfall, and ocean temperature are the main factors driving shrimp populations, according to fishers’ local ecological knowledge. Modeling also identified wind as an important predictor. Both the local ecological knowledge and our modeling results showed that white shrimp populations have been on the rise.

Our findings indicate that the local knowledge of fishers and scientific modeling are valuable for fisheries management and can inform policy decisions.

A more participatory approach for the shrimp fishery could enhance information exchange and mutual, perceived trustworthiness among fishers and managers.

the full study
“Environmental Drivers of Shrimp Abundance: Comparing Insights  from Local Ecological Knowledge and Empirical Modeling” in Frontiers  in Marine Science

see also
“Environmental and Climate Variability Drive Population Size of Annual Penaeid Shrimp in a Large Lagoonal Estuary” in PLoS ONE

more on sustainable fisheries   

Nadine Heck is an assistant professor in the Department of Coastal Studies at East Carolina University. Her research explores human-environment interaction in the context of fisheries, protected areas, and ecosystem-based adaptation.

James Morley is a fishery ecologist in the Department of Biology at East Carolina University.

Lela Schlenker is a marine ecologist with experience in research, scientific communication, teaching, and renewable energy.

Samantha Farquhar is a lecturer in marine and environmental science at the Coast Guard Academy.

This story originally appeared in North Carolina Sea Grant’s award-winning Hook, Line & Science series. Visit HookLineScience.com.