Tag Archives: exploitation of fisheries

Open-Ocean Farming

image from https://www.innovasea.com/

Ocean Farm 1is 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.

Advertisements

Justice 4 Fish

 image from News VietNamNet

Hundreds of people have held a rare protest in Vietnam against the unexplained mass death of fish on the country’s central coast. Vast numbers of dead fish have appeared across some 200km (125 miles) of coastline since early April. A government investigation has so far found no links to a steel plant owned by Taiwanese firm Formosa Plastics.But many of the demonstrators in Hanoi blamed the company, and carried placards saying “Formosa Out”. Other signs read “Formosa destroying the environment is a crime” and “Who poisoned the central region’s waters?”  Environment Minister Tran Hong Ha said the die-off was “a very huge and serious environment disaster” and admitted that the government had been slow to react.He said Formosa Plastics had been ordered to dig up an illegal waste pipe at its plant.

Fishermen along the affected coastline are banned from selling their stocks, but seafood industry officials said exports, that bring in $6.6b a year, would not be affected.

Excerpt from Vietnam protest over mystery fish deaths, BBC, May 1, 2016

Regulation of Deep-Sea Fishing by Depth: the scientific facts

setting a trawl. image from wikipedia

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, inCurrent 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

Another Way to Exploit African Countries; depleting their oceans by unsustainable fishing

Two-thirds of African countries have access to the sea. Some are making good use of it through fishing and tourism. But the productivity of African waters is plummeting….The main reason is bad governance. African Union calls to fight overfishing with joint navy patrols and co-operation between fisheries have been ignored. Nigeria, among Africa’s richest countries, lacks a serviceable navy. Some governments even collude in overfishing. Angolan fisheries officers rarely report the illegal catches of boats owned by politicians.  At the same time African states are failing to invest in much-needed marine research. They say it is a “donor activity”, meaning they want foreigners to pay for it. The continent has only one large oceanography department, at the University of Cape Town, and that is underfunded.

Coastal wetlands have little protection and fishing grounds are especially vulnerable. In many countries lot of foreign boats operate in areas close to the shore supposedly reserved for locals in dugouts. Some vessels use banned methods like light-luring (attracting fish with floodlights) and pair-trawling (where nets strung between boats are dragged on the sea floor).  Industrial fishing has been encouraged by rising global demand. The European Union has a series of agreements for its boats to fish in African waters. China has moved in too. The Russian fishing fleet is resurgent. In many cases, says André Standing, a researcher into fisheries agreements in Africa, it is not clear how much money is being paid for licences, or to whom. Critics say Africa’s failure to protect its ocean is political, the definition of a continent too weak to exert full control over its resources. A recent deal between Mauritania and China makes it hard to reduce the catch even if it is unsustainable.

Meanwhile the human footprint along Africa’s vast coastline is growing. The UN says African seaside cities are spreading by more than 4% a year…. Making the sea safer and more productive may be the best way to keep landlubbers peaceful. Experts have plenty of suggestions. Community initiatives could help get rid of dynamite-fishing and its ruinous effects. Conservation no-catch schemes such as one run by Blue Ventures, a Madagascan outfit, [of a UK charity] have proven their value. But there is too little money to scale them up. The best way to find the cash would be to point out the security costs of unhappy fishing communities to rich governments. Somalia’s piracy problem began in part as an armed response to illegal fishing in Somali waters. Some banditry in Nigerian waters started as a protest against the threat to fishing from the oil industry…..

The tributaries of Africa’s oceans are mostly clean and its mangroves in good condition, especially compared with those of Asia. But abuse is growing. With the sharks almost gone, Chinese diners are demanding manta rays and mobulid rays as ingredients for their expensive banquet stews. Frank Pope, an Africa-based writer on oceans, says that the slow-breeding rays could be gone even sooner than the sharks they used to swim alongside on the glittering reefs.

Excerpts, Africa’s oceans: A sea of riches,Economist, Feb. 18, 2012, at 52

See also Coalition for Fair Fisheries Arrangements