A diver inside one the cages at the cobia farm, which has a relatively low environmental impact. Photo: University of Miami.
A diver inside one the cages at the cobia farm, which has a relatively low environmental impact. Photo: University of Miami.

Offshore fish farming is the way forward say scientists

A study of a fish farming operation eight miles off the coast of Panama has concluded that offshore farming has the potential to produce a relatively small pollution footprint.

Publisert

The study led by scientists at the University of Miami (UM) Rosenstiel School of Marine and Atmospheric Science found minimal environmental impacts to the surrounding waters from Open Blue’s cobia farm.

Researchers collected water samples at one upstream and three downstream locations from the submerged fish cages to investigate if there were significant or cumulative impacts from the farm. Sediment samples were also collected to evaluate the effects of the aquaculture facility on the seafloor.

The data revealed that only small amounts of nutrients are released from the farm. The results also showed that any impacts from offshore fish farming are minimal compared to all other forms of animal protein production for human consumption.

Aaron Welch:  Open ocean "best if not the only environment" for expansion. Photo: LinkedIn.
Aaron Welch: Open ocean "best if not the only environment" for expansion. Photo: LinkedIn.

Relevant milestone

“We must produce 30 million tonnes of seafood to keep up with human population growth and increasing consumption of seafood – and the open ocean appears to be the best if not the only environment that would allow for this expansion,” said the study’s lead author Aaron Welch, who conducted the study while a graduate student at the UM Rosenstiel School and UM Abess Center.

“Showing that this can be done without incurring in a large footprint is something we will all benefit from. It’s a very relevant milestone to assist in developing offshore aquaculture in the Unites States.”

The fish farm houses 22 prism-shaped cages in waters from 55 to 65 metres deep, producing more than 1,400 tonnes of fish per year.

Low impact

“This study is of great interest to all stakeholders concerned with the expansion of offshore aquaculture in the United States and other countries,” said the study’s co-author Daniel Benetti, a professor in the Department or Marine Ecosystems and Society and director of aquaculture at the UM Rosenstiel School. “To our knowledge, this is the first report of its kind from a commercially scaled aquaculture facility utilising offshore submersible cage technologies.”

“This research shows that seafood production for human consumption can be produced in the offshore environment with relatively low environmental impact compared to other production methods,” added Benetti.

The study’s authors include Aaron W Welch, Sharein El Tourky, Zachary Daugherty, Gary Hitchcock and Daniel Benetti of the UM Rosenstiel School and Angela N Knapp of Florida State University.

The study received support from the National Oceanic and Atmospheric Administration (NOAA).