Save Water, Raise Fish

U.S. Department of Agriculture (USDA) scientists in West Virginia
and Maine are
working closely with a collaborator to save water as part of an effort to
develop recirculating water systems for cool- and cold-water fish production.

Scientists
with USDA’s Agricultural Research Service (ARS)
at the National Center for Cool and Cold Water Aquaculture (NCCCWA) in Leetown, West Virginia, and the National Cold Water Marine Aquaculture Center (NCWMAC) in Franklin, Maine, partnered with Steven Summerfelt of
the Conservation Fund’s Freshwater Institute in
Shepherdstown, West Virginia, to discover the best ways to produce fish that
live in cool and cold water in a closed system.

ARS
is USDA’s principal intramural scientific research agency. This research
supports the USDA priority of promoting international food security.

The
recirculating system Summerfelt developed doesn’t just move water around. It
uses as little as 4 percent new water each day, which means that a complete
water exchange only takes place every 25 days. According to Summerfelt, this
miserly use of water – an environmental plus – also allows recirculating fish
farm systems to be located in many places where traditional aquaculture
wouldn’t work.

William
Wolters, director of NCWMAC, found that the systems developed for his
facility’s particular needs are working well. Because Franklin has limited groundwater resources, a
system that reuses water was crucial. The recirculating systems have allowed
the researchers to raise their fish efficiently with a limited amount of water.

In
Leetown, scientists led by Caird Rexroad III at the NCCCWA are working with
trout, a fish that needs especially pristine water in order to live and thrive.
Twenty years ago, it was believed that trout couldn’t thrive in a water
recirculating system. Particularly sensitive to water quality, they will not
eat enough feed to grow if conditions aren’t right.