Tag Archives: fisheries resources

How to Kill One Million Fish: Murray-Darling

But it took a viral video posted on 8 January 2019 to drive home the ecological catastrophe that was unfolding in the Murray-Darling river system in Australia. In the footage, Rob McBride and Dick Arnold, identified as local residents, stand knee-deep among floating fish carcasses in the Darling River, near the town of Menindee. They scoff at authorities’ claims that the fish die-off is a result of the drought. Holding up an enormous, dead Murray cod, a freshwater predator he says is 100 years old, McBride says: “This has nothing to do with drought, this is a manmade disaster.” Arnold, sputtering with rage, adds: “You have to be bloody disgusted with yourselves, you politicians and cotton growers.”

Scientists say McBride probably overestimated the age of the fish. But they agree that the massive die-off was not the result of drought. “It’s about taking too much water upstream [to irrigate farms] so there is not enough for downstream users and the fish,” says Quentin Grafton, an economist specializing in water issues at Australian National University (ANU) in Canberra. The Australia Institute, a Canberra-based think tank, blamed “policy failure and mismanagement” in a 19 January 2019 report, but called drought a catalyst.

Excessive water use has left river flows too low to flush nutrients from farm runoff through the system, leading to large algal blooms, researchers say. A cold snap then killed the blooms, and bacteria feeding on the dead algae sucked oxygen out of the water,   This wasn’t supposed to happen. In 2012, the national government adopted the Murray-Darling Basin Plan, touted as a “historic” deal to ensure that enough water remained in the rivers to keep the ecosystem healthy even after farmers and households took their share.

In 2008, the federal government created the Murray-Darling Basin Authority to wrestle with the problem. In 2010, a study commissioned by the authority concluded that farmers and consumers would have to cut their use of river water by at least 3000 but preferably by 7600 gigaliters annually to ensure the health of the ecosystem. Farmers, who saw their livelihoods threatened, tossed the report into bonfires.  The final plan, adopted as national law in 2012, called for returning just 2750 gigaliters to the rivers, in part by buying water rights back from users. “It was a political compromise that has never been scientifically reviewed,” Williams says, adding that “climate change was never considered in the plan, which was a dreadful oversight.”..

Grafton says there are also suspicions of widespread water theft; up to 75% of the water taken by irrigators in the northern part of the system is not metered. Farmers are also now recapturing the runoff from irrigated fields that used to flow back into streams, and are increasing their use of ground water, leaving even less water in the system, says Mike Young, an environmental policy specialist at the University of Adelaide in Australia.

In February 2018, such issues prompted a group of 12 academics, including scientists and policy experts, to issue the Murray-Darling Declaration. It called for independent economic and scientific audits of completed and planned water recovery schemes to determine their effects on stream flows. The group, which included Williams and Grafton, also urged the creation of an independent, expert body to provide advice on basin water management. Young, who wasn’t on the declaration, wants to go further and give that body the power to manage the basin’s water, the way central banks manage a country’s money supply, using stream levels to determine weekly irrigation allocations and to set minimum flow levels for every river.

Excerpts from Dennis Normile, Massive fish die-off sparks outcry in Australia, Science, Jan. 22, 2019.

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

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.

Survival of Bluefin Tuna

Japanese call bluefin tuna “the king of fish”. They eat about 40,000 tonnes of it a year—80% of the global catch. Demand is also growing rapidly elsewhere. Yet Pacific bluefin stocks are down by 97% from their peak in the early 1960s, according to a recent report from the International Scientific Committee, an intergovernmental panel of experts. (Japan disputes its findings.) In some places, fishing is three times the sustainable level, the committee says.

Aquaculture might seem to offer a way out of this impasse. But the bluefin is hard to breed in captivity. In the open sea, it can roam for thousands of miles and grow to over 400kg. It is highly sensitive to light, temperature and noise. Early attempts to farm it fizzled, but Kindai University persisted long after an initial research grant from the government ran out in the early 1970s. In 2002, funding itself from sales of other fish, it managed to rear adult tuna from eggs for the first time, rather than simply fattening up juveniles caught at sea. Now the chefs in Ginza can have a tuna zapped with an electric prod and yanked out of the university’s tanks on demand.

However, just 1% of the bluefin the university rears survive to adulthood. “We expect this to improve but it will take time,” predicts Shukei Masuma, the director of its Aquaculture Research Institute. Worse, the tuna gobble up lots of wild mackerel and squid. Scientists have experimented with soy-based meal and other alternatives. A company in south-western Japan said this month that it had managed to raise tuna using feed made of fishmeal, but it is costly and the fish are slow to thrive. Using wild fish for feed makes bluefin farming unsustainable, says Atsushi Ishii of Tohoku University. He sees aquaculture as a distraction from the thorny task of managing fisheries properly.

This debate is slowly seeping into the public consciousness. In 2014 the media made much of the decision of the International Union for Conservation of Nature, a conservation body, to put bluefin tuna on its “red list” of species threatened with extinction.

Excerpts from The Japanese Addiction to Tuna: Breeding Bluefin, Economist, Sept 24, 2016

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

Resuscitating Collapsed Fisheries: catch shares

For American fish, this is a good time to be alive. On May 14th, 2012 the National Oceanic and Atmospheric Administration (NOAA) reported that a record six federal fisheries returned to health last year. After a decade of similar progress, 86% of America’s roughly 250 federally monitored commercial fish stocks were not subject to overfishing; 79% were considered healthy…

In the late 1980s cod fisheries in the Gulf of Maine and Georges Bank collapsed. This led to efforts to improve the fishery act, in 1996 and 2006, which forced the eight regional bodies that manage federal fisheries to introduce science-based quotas and ten-year recovery programmes for depleted fisheries. The recent recovery of species, including New England scallops, mid-Atlantic bluefish and summer flounder and Pacific lingcod, is the result. This signals another truth: given a break, the marine environment can often replenish itself spectacularly.

America’s fisheries are probably now managed almost as well as the world’s best, in Norway, Iceland, New Zealand and Australia. Yet there is plenty of room for improvement. State-run fisheries, which tend to be close to shore and dominated by small-scale and inefficient fishermen, are less well funded and well managed and much poorer for it. New England groundfish stocks, including cod, have also not recovered: they account for 13 of the remaining depleted populations. This appears to be partly the result of environmental change, climatic or cyclical.

And the politicians are still interfering. On May 9th the House passed legislation forbidding NOAA from developing an innovative means of apportioning fishing quotas, known as catch shares. These are long-term, aiming to give fishermen a stake in the future of their fisheries; market-based, since they can be traded; and, in practice, good for fish. Sadly, the two Republican congressmen behind the ban consider they have been designed “to destroy every aspect of American freedom under the guise of conservation”.

Fish stocks: Plenty more fish in the sea, Economist, May 26, 2012, at 32