Tag Archives: sustainable fisheries

Unwanted Fish: Another Waste

Long before fillets reach your dinner plate, lots of seafood is thrown away. Overboard, actually. As fishing crews sort through their catches, they toss unwanted fish back into the sea—as much as 20% of the global catch. The vast majority die. On 1 January, 2019 the wasteful practice became illegal in waters of the European Union. Scientists believe the policy will lead to more efficient fisheries and eventually boost stocks, while incentivizing more selective fishing gear and strategies. But in the short term it could mean hardship for the industry and perhaps even compromise fisheries data, if hidden cheating becomes widespread.

Few expect all fishing vessels to obey the discard ban. “Put yourself in the boots of a fishermen who can see he will run out of quota for a species. If he does, he would have to tie up for the rest of the year. He might have to sell the boat, or sell the house,” says Barrie Deas, CEO of the National Federation of Fishermen’s Organisations in York, U.K. “What’s he going to do?”  Scofflaws could jeopardize not just fish stocks, but also data about how they are faring. Researchers, who suggest catch levels to regulators, get their discard data largely from independent observers on just a few boats—less than 1% of the EU fleet. Observed boats are now likely to discard much fewer fish than other vessels, leaving an official undercount of the discard rate and a falsely rosy picture of how heavily stocks are fished, says Lisa Borges, a fisheries biologist who runs a consultancy called FishFix in Lisbon. “It could bring about a very big, negative change,” Borges says. “I get very worried about European fisheries management.”

Environmentalists want to toughen up enforcement by installing cameras on ships, the practice in New Zealand and a few other places with discard bans. But Voces de Onaindi says this is impractical on some vessels and raises privacy concerns. Countries where discard bans have succeeded, including Norway and Iceland, have gradually introduced incentives and controls to develop the economic use of unwanted fish and create a culture of regulatory compliance. Those steps, Andersen says, lessen conflict but can take decades to achieve.

Ships banned from throwing unwanted fish overboard
Erik Stokstad

Fishing in the Arctic: Banned

The Agreement to Prevent Unregulated High Seas Fisheries in the Central Arctic Ocean (CAO) in Ilulissat, Greenland was adopted on October 3, 2018.  The historic agreement represents a collaborative and precautionary approach by ten countries to the management of high seas fish stocks in the Central Arctic Ocean. The agreement covers approximately 2.8 million square kilometers, an area roughly the size of the Mediterranean Sea.

Ice has traditionally covered the high seas of the central Arctic Ocean year-round. Recently, the melting of Arctic sea ice has left large areas of the high seas uncovered for much of the year. The Agreement bars unregulated fishing in the high seas of the central Arctic Ocean for 16 years and establishes a joint program of scientific research and monitoring to gain a better understanding of Arctic Ocean ecosystems. It also authorizes vessels to conduct commercial fishing in the CAO only after international mechanisms are in place to manage any such fishing. This effort marks the first time an international agreement of this magnitude has been proactively reached before any commercial fishing has taken place in a high seas area.

Signatories include the United States, Canada, the Kingdom of Denmark, the European Union, Iceland, Japan, the Republic of Korea, the Kingdom of Norway, the People’s Republic of China, and the Russian Federation.

Excerpt from U.S. Signs Agreement to Prevent Unregulated Commercial Fishing on the High Seas of the Central Arctic Ocean, NOAA Press Release, Oct. 3, 2018

Open-Ocean Farming

Ocean Farm 1 is the first of six experimental fish farms ordered by SalMar, a Norwegian firm, at a total cost of $300 million. InnovaSea, an American firm, makes large open-ocean aquaculture nets called SeaStations, which are currently used off the coast of Panama and Hawaii, but Ocean Farm 1 is “by far the largest open-ocean fish farm in the world,” says Thor Hukkelas, who leads research and development on aquaculture at Kongsberg Maritime, a Norwegian engineering company. Mr Hukkelas’s team provided Ocean Farm 1’s sensor system: 12 echo sounders mounted on the bottom of the frame, high-definition cameras dangled into the water at different depths, oxygen sensors and movable, submerged feeding tubes.

Fish farming plays an increasingly central role in the provision of sufficient amounts of protein to Earth’s population. People eat more fish globally than beef, and farmed fish account for almost half of that amount  Many wild fisheries are already at or past their sustainable capacity, so efforts to make fish farming more productive are vital.

Ocean Farm 1 aims to automate what is an expensive and difficult business, and to solve two key problems that occur in near-shore aquaculture: that there is not enough space and that it is too polluting. The excrement from millions of salmon can easily foul up Norway’s fjords, and their shallow, relatively still water is a breeding ground for sea lice. In the open ocean the water is deeper and better oxygenated. The currents are stronger and so better able to sweep away excrement.

Near-shore farms normally spread feed on the water’s surface and allow it to sink, but Ocean Farm 1 has 16 valves at varying depths, through which feed can be pushed. By putting it farther down in the cage it is able to keep the salmon in deeper water. The salmon are fine with this. The sea lice, which like the shallows, are not.

All of this means the number of fish can be increased. The Norwegian government wants to triple its aquaculture production by 2030 and quintuple it by 2050. “Scaling up of traditional aquaculture is not going to reach these high-growth ambitions,” says Mr Hukkelas.

Kongsberg is gathering data from all the sensors on the farm to build a machine-learning model, called SimSalma, which learns the behaviour of the salmon in order to optimise their feeding. Currently, human operators on the structure decide when and where to feed the fish by examining the data. By 2019 Kongsberg plans to have automated this, pushing feed at optimum times and places and reducing human involvement. The success and expansion of such projects would represent a major step towards maintaining global fish stocks.

Net gains: Open-ocean fish farming is becoming easier, Economist,  Mar. 10, 2018.

Regulation of Deep-Sea Fishing

A study published in 2009 suggested that in all but the deepest of their waters—those with a seabed closer than 1,500 metres to the surface—yields had dropped by 70% over 25 years. Even in the abyss below that depth, the fall was 20%. To try to stem this decline the European Union, which regulates fishing in much of the area, is proposing to limit the depth at which trawling can take place. This would, in effect, create a marine reservoir below that level, a form of protection additional to the system of species-specific quotas that already exists. The question is where the line below which trawl-gear is forbidden should be drawn. And, until now, there have been few scientific data to inform that decision.
This has just changed, however, with the timely publication, in Current Biology, of a study by Jo Clarke of Glasgow University and Francis Neat of Marine Scotland Science, a government agency. Their work suggests that the appropriate cut-off would be at a depth of 600 metres—below which the ecological damage caused by trawling increases substantially.

Ms Clarke and Dr Neat derive their conclusion from data collected between 1978 and 2013 by Marine Scotland Science and the Universities of Aberdeen and St Andrews. These data record species caught, and also the depths of the trawls that caught them, which ranged from 250 to 1,500 metres.

The researchers note that biodiversity increases with depth. On average, an extra 18 fish species show up with each 100-metre increase. Many of these, though, are of little commercial value. Such so-called by-catch gets thrown back, but by then most of it is dead. And that, particularly because deep-sea species tend to grow more slowly than those which live near the surface, and have lower fecundity rates, can have profound effects on ocean ecology.  Trawls at 300 metres, Ms Clarke and Dr Neat found, have a ratio of catch to by-catch (in terms of weight) of five to one. At 600 metres the ratio is around three to one. At 800 metres, though, it is ten to nine; at 1,000 metres one to one; and at 1,200 metres, one to two.

Based on these findings, Ms Clarke and Dr Neat suggest that a trawl limit of 600 metres would be a suitable compromise between commercial reality and ecological necessity.

Excerpts from Fisheries: Drawing the line, Economist, Sept.  5, 2015, at 80