Growing shrimp close to home

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New Hampshire-raised shrimp may be coming to your seafood platter next year, thanks to researchers at UNH who are currently testing a small aquaculture system used to grow this popular shellfish.  

Shrimp aquaculture has the potential to at least partially fill the void left in the local shrimp market. Ever since the close of the wintertime Gulf of Maine shrimp fishery due to its stock collapse in 2013, many New England fishermen have struggled to find work in the cold-weather months. That fishery closure has also left local seafood lovers with the decision to either forgo eating shrimp or to purchase those grown or harvested from much farther away. Locally raised, antibiotic-free shrimp could be a winning solution for fishermen and consumers alike right here in the Granite State.

And the best part: It takes relatively little space to grow these shellfish.

“If you’ve got a spare bay in your garage or space in your barn or basement, you’ve got the room to grow shrimp,” said Michael Chambers, aquaculture specialist for N.H. Sea Grant/UNH Cooperative Extension. “We wanted to first test the viability of the system, work out the hiccups and hopefully get fishermen and other interested individuals on board with this new opportunity,” he added.

four small white shrimp

Above: Shrimp grown in the aquaculture system at UNH's Jackson Estuarine Lab.

Shrimp aquaculture is gaining momentum in the Midwest, but has yet to really take off here in New England; Chambers is hopeful that it will. It’s a relatively low-cost operation, he explained. His prototype tank, housed in the greenhouse of UNH’s Jackson Estuarine Lab at Adams Point, holds 2,000 shrimp that will be harvested once they grow to reach 20 grams each — a process that takes about four months.  

A peek over the edge of the tank reveals big frothy air bubbles that coat the warm water surface, and occasionally a shrimp pops up with the water’s aeration gyre. Chambers isn’t growing the small native Gulf of Maine shrimp, though — that coldwater species grows very slowly, he said, so instead he chose Pacific white shrimp for their quick growth and larger size. Would-be shrimp farmers can purchase the juvenile shrimp via mail order from Vero Blue, a Texas-based company, grow them in a 6’x6’x4’ tank and harvest about 50 pounds three times per year.

Chambers and UNH marine biology student Erich Berghahn (’17) have been trying different water pumps, aerators, filters and other components to see which work best for this effort. But the trickiest part of the whole set-up, Chambers explains, is getting the biofloc in the tanks properly adjusted. Biofloc is a soup-like substance that consists of bacteria, algae, zooplankton and other living organisms. Like a sourdough starter for bread, biofloc requires adjustments to keep it alive — sugar or molasses helps to feed the biofloc organisms, and baking soda increases the pH when necessary. The pinkish-brown soup provides sustenance for the shrimp and offers a water cleaning service by metabolizing the nitrogen waste products from the shrimp.

pink-brown bubbles on water surface of aquaculture tank.

Above: Bubbles on the water's surface.

Pelletized shrimp feed provides a secondary food source for the shrimp, and the water quality is checked daily — a responsibility shared between Berghahn and Chambers this semester. Despite the small time commitment needed to grow the shrimp, local fishermen, shellfish farmers and others have expressed interest in setting up their own aquaculture system once the methodologies are perfected by the researchers.

“The initial results look promising, but there are tricks to maintaining a strong, healthy biofloc and biosecure system,” Chambers said. “We learn something new every day,” he added.

two men hold flask filled with pink-brown biofloc.

Above: Michael Chambers (L) and Erich Berghahn (R) test the system's biofloc daily. 

For more information, please contact Michael Chambers at: michael.chambers@unh.edu.

N.H. Sea Grant promotes the wise use, conservation and sustainable development of marine and coastal resources in the state, the region and beyond. Located at the University of New Hampshire, NHSG is part of a national network of programs located in our coastal and Great Lakes states as well as in Puerto Rico and Guam.  

Rebecca Zeiber, N.H. Sea Grant Science Writer