Lessons in Green Fish Farming

Virginia Marine Resource Bulletin
Volume 43, Number 1, Winter 2011
By Margaret Pizer

On a sweltering humid day last August, it was all hands on deck at the Mid-Atlantic Aquatic Technology (MAAT) fish farm in Quinby, VA. Owner Clarke Morton inserted a hinged screen into one of the farm’s 7,000-gallon round tanks and used it to corral thousands of 5-inch-long spot (Leiostomus xanthurus) into a corner while farm manager Chris Bentley and hatchery technician Idris Riskey used a net to scoop the fish into buckets. They carted the buckets of fish to a customer’s pickup truck and emptied them into plastic barrels that he had rigged up in a trailer for the drive back to Atlantic City.

Although the late summer heat made it hard to imagine, heating the hundreds of thousands of gallons of water circulating through the facility’s tanks is a problem for the farm. Propane is a significant expense during the winter months. Thus Morton and Bentley were excited to show off the newly installed solar thermal water heating system. This January, the system became fully operational, and in the first month it was able to fulfill all of the heating requirements for MAAT’s 15,000-gallon system—at an estimated savings of about $20 a day in propane. Over the course of an entire winter, this should amount to savings of at least one to two percent of the fish farm’s total operating budget.

Launching an Aquaculture Business
MAAT’s system is the fruit of a long collaboration between Morton and Virginia Sea Grant staff at Virginia Tech’s Virginia Seafood Agricultural Research and Extension Center (VSAREC) and Virginia Institute of Marine Science (VIMS). In fact, Morton began interacting with Virginia Sea Grant extension staff even before he chose a site for his facility in 2002.

For Morton, who practices emergency medicine in Newport News, fish farming allows a unique melding of his concern for the environment with his interest in human health—mixed in with more than a dash of entrepreneurial spirit.

“I wanted to start a business that actually helps the environment,” says Morton, who was drawn to fish farming as a way to sustainably meet demand for seafood and provide people with fish-based omega-3 fatty acids that are important for human development and health.

With these goals in mind, Morton sought advice and help from Virginia’s various extension programs to start a finfish aquaculture business. He credits VSAREC’s Mike Schwarz with helping him design the MAAT building, a large metal barn with several smaller greenhouse-like structures inside. A setup developed by VIMS’s Mike Oesterling served as the model for Morton’s seawater system. Market surveys conducted by Oesterling also helped Morton choose the species of fish he’d grow.

“I went to a conference that Mike Oesterling put on, and he spoke about spot as live bait and entering the bait market,” says Morton. “He was convinced that spot was the best bait to grow based on his market surveys.” So Morton decided to use the spawning techniques and culture systems developed by Oesterling at VIMS to give fish farming a try.

Energy Savvy
At the same time, Morton began collaborating with Bob Lane of VSAREC on energy efficiency and alternative energy projects. Before the facility was built, Lane helped Morton plan for energy expenditures by performing an energy audit. An energy audit analyzes a facility’s use of oil, gas, electricity, or other energy sources to identify ways to reduce costs. Lane’s initial energy analysis prompted Morton to think about ways to incorporate alternative energy into the facility.

The first source of alternative energy that MAAT pursued was wind energy. Using the results of a later energy audit Lane performed, Morton completed the paperwork to have an anemometer installed at the MAAT facility. The instrument, the result of a collaboration between the Virginia Department of Mines and Minerals and the Virginia Wind Energy Collaborative based at James Madison University, was mounted on a 50-meter tower to measure the potential for wind energy. Measurements showed that wind rates are not high enough at MAAT to make the use of wind energy feasible at this time. Nevertheless, the project has provided baseline data that may help Morton’s farm or other farms on the Eastern Shore to use wind energy in the future.

“From what I understand, you need to get [the wind turbines] higher to get out of the way of the barrier islands,” explains farm manager Bentley. That would necessitate wind turbines that would be higher and larger than is currently feasible for MAAT. “We’re leaving [the anemometer] up for a second year for data collection for some other companies that are interested . . . because it’s valuable data for the whole area,” he says.

Heating Up
MAAT’s most recent energy audit was aimed at determining which renewable technologies would give the facility the best return. Solar thermal seemed to be a natural choice since MAAT’s spot must be maintained in water at about 75°F year round. Lane analyzed the amount of energy that a solar thermal system could generate for the farm and determined that “It looked feasible with a reasonable payback period.”

Morton and Bentley then learned about a variety of incentives that would help pay for the system. “With the grants, the whole project was essentially paid for,” Morton explains. “The thing ended up costing me about $376 instead of $67 to $70 thousand.”

The system uses solar panels on the facility’s roof to heat water and then stores the hot water in a large holding tank. In addition to offsetting heating costs, the solar thermal system should help MAAT maintain their fish at warmer and more constant temperatures through the winter, which should lead to faster growth.

Morton and Bentley are already looking forward to the next improvement. They hope to evaluate whether the solar thermal system could be used to cool the facility in the summer through adsorption cooling.

Energy economy and smart planning have been a big part of MAAT’s success, enabling it to grow from an output of 125 fish in 2006 to this year’s output of more than 45,000 spot.

“Through the different people who have helped him, Clarke has put together a program that has a low overhead,” says Lane. “MAAT’s energy use is one of the lowest in the industry for the number of fish that they’re growing, and that is due to the way they built [the facility] and the energy analysis that we did.”
Lane thinks that many aquaculture and seafood businesses could benefit from following in Morton’s footsteps. He cites a few other examples of alternative energy projects in Virginia’s aquaculture industry, including a trout farm that is researching hydroelectric turbines. The Department of the Interior has also expressed interest in implementing some of MAAT’s practices at fish farms on Native American reservations.

“People tend to think more about, ‘How do we get product through our plant; that’s where our dollars are,’ and that’s what seems to take precedence,” says Lane. “But Clarke’s beginning to see the rewards of making those energy analyses up front and then buying the right equipment.”