The worldwide population may be growing and the demand for more food along with it, but a team of UCSB researchers from the university’s Bren School of Environmental Science & Management and Marine Science Institute has a possible solution to put more fish into the sea: Offshore fish farming in the Caribbean.
According to a UCSB press release summarizing the team’s study in the journal Nature Sustainability, conducting fish farming, or aquaculture, in the region’s off-shore regions not only has the potential to produce large quantities of fish, but to avoid the high environmental impacts of its land-based version.
Under the researchers’ “conservative” estimates, offshore aquaculture in the Caribbean could produce 34 million metric tons of seafood per year, twice as much as the region’s current output.
Marine Science Institute researcher and study lead author Lennon Thomas said that this large output can be produced in a “relatively small amount of ocean space,” a major advantage of offshore fish farming. She added that roughly half of the current global wild fisheries catch, 40 million metric tons of seafood, could be produced on less than 1.5 percent of the region’s exclusive economic zones, according to the team’s models.
In addition to using less land, conducting fish farming offshore has less potential for negative environmental impacts. According to the release, this is due to deeper water and stronger currents preventing adverse water quality impacts and distance limiting the effects on sensitive coastal habitats like coral reefs and seagrass meadows.
Study co-author Sarah Lester said because offshore aquaculture is “space efficient,” there’s great room for choosing locations that strike a balance between commercial gains and sustainability.
“So we can be really selective about where we locate fish farms, choosing locations where profitability is high and economic impacts are low,” she said.
The team also took socioeconomic and political factors into account to determine risks involved with investing in fish farming in each of the Caribbean’s countries.
Using cobia, a premium fish suitable to be farmed in warmer waters, as a model species, the researchers came up with three scenarios. The first considered the results of farming in all suitable areas in the region. The second considered only areas that would be profitable over 10 years and at a 10-percent discount rate, and the third considered only areas that would be profitable over 10 years with discount rates between 10 and 25 percent.
All three scenarios yielded “promising” results, according to the release.
Paper coauthor and MSI researcher Tyler Clavelle said that even though cobia farming is expensive, “there are large areas of the Caribbean that could be profitable for off-shore aquaculture.”
Areas with the greatest potential for aquaculture were found to be Trinidad and Tobago and the Bahamas, with approximately 8,500 and 4,100 square kilometers of areas profitable for fish farming, respectively.
However, offshore aquaculture isn’t a risk-free proposition. Insufficient capital poses a significant barrier to developing it in the Caribbean and as it is a newer industry carries more inherent risk.
The release also mentions political and economic instability in the region increasing risk for foreign investors.
The UCSB team is currently looking into the impact of the Caribbean’s fish farming policy on development trends to complement the findings of their study.
The left map shows areas in red suitable for Caribbean cobia fish farming. The right map shows researchers’ estimates on how much seafood each offshore region can produce.