Saving Seafood

How Ocean Aquaculture Could Feed the Entire World – and Save Wild Fish

Marine researchers at the University of California, Santa Barbara, mapped out the potential of the open ocean to support farmed fish and came to some surprising conclusions.

August 21, 2017 — About five out of every six fisheries worldwide has reached or passed the limit of what it can sustainably produce, according to the World Wildlife Fund. Drought, dams, agricultural runoff and other pressures have depleted wild salmon populations in the Eastern Pacific, while on the east coast of North America, wild Atlantic salmon exists mainly in the memories of the Greatest Generation. Bluefin tuna, the preferred delicacy of the world’s finest sushi chefs, is at 2.7 percent of its historical population – about the same as the Bengal tiger.

Meanwhile, seafood farmed in coastal regions has been infected with sea lice, pollutes neighboring ecosystems with waste, sometimes produces fewer nutrients than are fed into the system, often destroys carbon-sequestering mangroves and can require large amounts of antibiotics to stave off disease.

But according to a new study from the University of California, Santa Barbara’s Bren School of Environmental Science and Management, aquaculture could feed a global population expected to grow to nearly 10 billion by 2050. Lead author Rebecca Gentry, a newly minted PhD in marine ecology, and her colleagues wrote that the open ocean “is largely untapped as a farming resource,” representing “an immense opportunity for food production.” In the study published August 14 in the journal Nature Ecology & Evolution, they found that the entire world’s current output of wild-caught seafood could be farmed in areas that in total would comprise just 0.015 percent of the ocean’s surface area, if grouped together in a way that the authors note would not be realistic or recommended. That’s the equivalent to the size of Lake Michigan.

“People assume the oceans are big but no one had quantified it,” Gentry said. “There’s not that much broad-scale ecological research on marine aquaculture, so we needed a base of information to get an idea of where we can do it.”

Read the full story at Aquaculture Magazine

New study examines how China maintains large catches and what it means for fishery management elsewhere

January 19, 2017 — China, the world’s largest seafood producer, has done something extraordinary. For the past 20 years, despite minimal management and some of the most intense industrial fishing in the world, it has maintained large catches of key species in its most productive waters.

That same kind of intense, lightly managed industrial fishing has collapsed other fisheries, such as Newfoundland’s cod fishery in the 1990s. China’s ability to sustain its catches has puzzled scientists, some of whom have even questioned the accuracy of the country’s catch reports.

A new study from UC Santa Barbara, published in the Proceedings of the National Academy of Sciences, suggests another explanation: By reducing the population of predatory fish, China has increased populations of preyed-upon species.

“If you fish down the large predatory fish, then you can catch more small prey fish, because they are no longer being eaten before you get to them,” explained lead author Cody Szuwalski, a fisheries scientist in UCSB’s Sustainable Fisheries Group. The group is a collaboration of the campus’s Marine Science Institute and Bren School of Environmental Science & Management.

Read the full story at Phys.org

Can farmed fish feed the world sustainably?

September 14, 2016 — The world’s population is expected to soar by 2.5 billion people by 2050, bringing a host of global challenges – including how to feed so many hungry mouths.

If projections hold, the global demand for animal protein will double over the next four decades, rising along with pressure to find ecologically sustainable food production practices.

Could farmed fish save the day? Just maybe, says UC Santa Barbara’s Steve Gaines. He and his team looked at wild-caught fish, farmed fish and land-based farming to assess the most viable long-term options.

The surprise: Fish farming floated above the rest for ecologic and economic reasons.

But there’s one big catch: Aquaculture has gotten a bad rap with American consumers.

“I meet people all the time who say, ‘I will only eat wild fish because aquaculture is bad,’” said Gaines, dean of the Bren School of Environmental Science & Management at UC Santa Barbara.

Gaines has been working to change minds about aquaculture, speaking at conferences around the country like this week’s Monterey Bay Aquarium Sustainable Foods Institute.

While some forms of aquaculture can harm the environment, others have a much lower impact, especially when compared to raising livestock – and in some cases even compare favorably to an entirely vegetarian diet, he said.

Read the full story from the University of California