Steve Gillman

30 April 2015

water Feature

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Overfishing – What’s Left In Our Oceans?
30 April 2015
Steve Gillman |

water Feature by RevolveTeam

The Global Catch

In 2011, the global volume of fish caught by fisheries was 93.7 million tons. It was the second highest catch ever landed, just under the record of 93.8 million tons in 1996. The European Commission revealed in October 2014 that a positive long-term trend of increasing fish populations is happening. With such a huge amount of fish being captured in recent years and populations supposedly on the increase, surely our oceans are not as empty as we think?

“In the UK, we have sophisticated fleets made up of powerful shipping vessels, but in the 1880s a fleet of sailing boats using wooden beam trawls landed more fish than we do today,” says Professor Callum Roberts, a marine conservation biologist at the University of York.

Levels of fishing have remained high thanks to the introduction of better technology. Long-line nets in the 19th century gave way to beam trawls that were then motorized in the 1880s. These were then replaced in the early 20th century by otter trawls which could also drag much bigger nets. Steam trawlers were soon replaced by diesel trawlers with their upgraded nets and then the boats were equipped with echo sound. New technology continues to be used today that enables fishermen to locate schools of fish that would have otherwise remained unknown.

“All of these advances have enabled the fishing industry to remain productive even if the abundance of what they’re pursuing is declining and the ecosystems are shifting from complex abundant habitats to less productive ones,” says Professor Roberts.

Blue fin tuna, Atlantic halibut, Beluga sturgeon, goliath grouper and the orange roughy – these are five fish that have become endangered in recent years. When sought after species like these become scarce, fishermen move onto other species that will sell.  This is something called “fishing down the food web”. According to Ransom A. Myers and Boris Worm from the Biology Department of Dalhousie University in Canada, over the last 50 years, the abundance of large predator fish, such as cod, swordfish and tuna, has dropped 90%. Fishing vessels now increasingly pursue the smaller forage fish, such as herrings, sardines, menhaden and anchovies whose populations have grown thanks to fewer predators.

Enter Trawling

Apart from poison, dynamite and drift nets, very few other fishing techniques have been banned completely. The reasoning behind the bans was due to the threat the techniques posed to fish stocks and to consumers.  Now, another method has come under equal scrutiny for the long-term damages it can cause to fish stocks and to marine habitats.

Trawling is a method of fishing that involves pulling a huge net through the water behind one or more boats. This method of fishing has been around since the 19th century and has developed to be a very efficient way to catch many fish at once. There are now different types of trawling, depending on the gear used, depth fished and species targeted. Trawling is a diverse fishing practice with some approaches a lot more detrimental than others.

The Margiris KL749, a Lithuanian super trawler, 30 miles off the coast of Mauritania. Source: Pierre Gleizes/Greenpeace

“On the west coast of the UK, we use two highly destructive methods. One of them is prawn trawling and the other is scallop dredging,” says Professor Roberts. “Scallop dredgers dig up the sea bed to catch scallops, they eliminate anything living in its path. Prawn trawlers use a very fine mesh net to catch prawn and eliminate any juvenile fish that would normally sustain important fisheries.”

Fishing using these two methods will not create any new fisheries because by-catch and habitat destruction effectively kills any future business. This is the end result of “fishing down the food web”.

Scallop dredging is another destructive method which kills off any hope of a productive fishery. It is a type of bottom trawling which drags its weighted nets across the sea bed, destroying habitats and aggressively illuminating a lot of species. Deep sea habitats are some of the slowest growing habitats in the world and the long-term damage caused by a bottom trawler may prevent ecosystems from every recovering.

Prawn trawling, scallop dredging and super trawlers are the most controversial methods. In Australia, the government has banned super trawlers because of the amount of bycatch they take in. The ban focuses on boats over 130 meters in length, but smaller trawlers can have the same capacity to harvest similar amounts of fish. The reality is that there are a variety of trawler ships and equipment being used because our oceans’ fishing grounds are very diverse. When a sustainable amount of fish needs to be taken from the oceans, then the trawling debate becomes more nuanced.

For example, in certain environments where the ground is sandy it is not clear that trawlers cause significant damage and it’s possible, if used modestly, they could be used in a sustainable manner to harvest bottom dwelling species. Elsewhere, in the middle of the water column there is an area called the pelagic zone: this is an area occupying 1,370 million cubic kilometers which is the habitat for 11% of known fish species. Here,the pelagic fish could be harvested within sustainable limits while there is no sea bed for trawlers to damage.

Managing The Means

In 2011, Proceedings of the National Academy of Sciences of the United States of America (PNAS) published a paper forecasting a collapse of the sardine stock in the north-east Pacific Ocean, but the sardine fishing quota continued to increase: in 2011, the fishery catch was 10.59% of the total biomass and 18.4% in 2012. Between 2012 and 2013, the sardine population dropped about 30% to 333,268 metric tons. This drop is considered the second great sardine crash and has been compared to the first notorious crash of the late 1940s and 1950s. In 2014, the Pacific Fishery Management Council took notice and reduced the quota 33% below from the previous year’s limits. The limits have since increased again.

Similarly, the International Commission for the Conservation of Atlantic Tunas’ (ICCAT) quota for 2008 was 28,500 tons, followed by 22,000 tons in 2009 and 12,900 in 2011, a year in which the fish became listed as endangered by the International Union for the Conservation of Nature (IUCN).  In November 2014, fishing nations agreed to a 20% annual increase in quotas over the next three years with countries like France and Japan pushing for higher quotas than what they received. Concerns remain that conservation efforts from previous years will quickly fade and the blue fin tuna will again be pushed to point of collapse.

Why is it that fisheries always seem to receive bigger quotas than what scientists recommend? And how come fishing restrictions aren’t enforced long enough? The simple answer is that there is money to be made when demand is high. The FAO says that fishing is the livelihood for 12% of the world’s population and even though 90% of these jobs are based in small-scale fisheries, there are still millions of people depending on our oceans to pay their wage.

This raises the concern of how fishermen can keep their jobs if there are no fish left to catch. It has become apparent that if you want a diverse fishery that is productive and supports a wild variety of different sectors of the fishing industry you have to manage the sea in a much smarter way.

Europe is making some progress with the Common Fisheries Policy (CFP), essentially “a set of rules for managing European fishing fleets and for conserving fish stocks”. Designed to manage a common resource, it gives all European fishing fleets equal access to EU fishing grounds and aims to allow fishermen to compete fairly.

Europe may want to treat their Member State fishermen fairly, but what about countries outside their jurisdiction?

In October 2014, the European Commission banned fish imports from Sri Lanka for illegal fishing and issued them with a ‘red card’ – a label used to highlight the worst offending countries. The reasons behind the ban were stated as “shortcomings in the implementation of control measures, a lack of deterrent sanctions for the high seas fleet, as well as lacking compliance with international and regional fisheries rules”. It is all well and good to highlight countries that are a threat to sustainable fishing, but Europe could arguable be just as guilty.

“Europe should get a red card themselves for a lot of dodgy operations on the West African Coast. One of the problems with overfishing in our own waters is that we have exported a lot of it to other countries,” says Professor Roberts.

“We cut deals with these countries and we pay them to allow our vessels to fish their stocks. There is very little oversight or good management.There is very strong evidence that we are depleting those fisheries now.”

Illegal fishing is a worldwide problem, but fishing access agreements can be just as damaging and should be put under as much scrutiny too. If we hope to achieve a degree of sustainable fishing, a system needs to be in place that sets fair limits and does not exploit other countries. It should also be supported by systems that work with the oceans and not against them.

Protect and Farm

By fully protecting some of the sea and eliminating exploitation from marine protected areas, fish stocks can rebuild their numbers and could replenish fisheries through their movement. Combine that with a sensible quota and the makings of a sustainable fishing market begin to take shape.

At the World Parks Congress last November, the President of Gabon announced that 23% of their marine waters were to be protected; while an agreement between the United States and the island nation of Kiribati was made to protect an area of the Pacific Ocean covering 490,000 square miles.

Reforms to the European Common Fisheries Policy came into force on 1 January 2015. The progressive elimination of wasteful discarding was addressed better, but other aspects that could prove pivotal to implementing sustainable fisheries were left out.

“A requirement to establish marine protected areas was not integrated in the fisheries report, but on the other hand there was a clause that said states are encouraged to create fish stock conservation areas which are essentially marine protected areas,” says Professor Roberts.

Another approach to make our fisheries more sustainable is aquaculture or fish farming. According to the FAO, global aquaculture production attained another all-time high of 90.4 million tons in 2012 and was worth an estimated $144.4 billion.

Fish farms can secure our supply, but they may be more of a burden to our oceans than a boost. Large quantities of wild fish are being caught to feed aquaculture like salmon. It takes approximately 2.5kg of wild fish to grow one kilo of farmed salmon.

On the other end, there is good aquaculture that sustains itself like muscle farms, they filter feed in the water and they do not require supplemental feeding and contribute to good water quality. But there can be bad muscle farming too. In Ireland, for example, they use huge mesh nets to catch wild muscles for farms.

Whether it is trawling or aquaculture, the vast and complex world of fishing has both positives and negatives. The path to establishing sustainable fisheries will be one that simultaneously promotes environmental recovery and supports a productive industry. The livelihoods of 12% of the world’s population depend on this sector so it is in our interest to make it a more self-sustaining and efficient system. After all, fishing less does not have to mean catching less – it may just be that we can actually catch more.

  • Arctic trawl catch Grimsby mid 20th century. Source: Professor Callum Roberts

  • Gutting cod in Hammerfest, Denmark. Source: Professor Callum Roberts

  • A Brixham trawler, is a type of wooden, deep-sea fishing trawler first built in Brixham in Devon, England, in the 19th century and known for its high speed. Source: Professor Callum Roberts

  • Lorenzo Mitchell Henry 851 pound tuna 1933. Source: Professor Callum Roberts

  • Before the auction at Tsukijij Fish Market in Tokyo which happens most mornings (except Sundays, holidays and some Wednesdays) at 3:00 a.m. with the arrival of the products by ship, truck and plane from all over the world. Source: Glenn Forbes/Flickr

  • The tuna auction at Tsukijij Fish Market in Tokyo happens most mornings (except Sundays, holidays and some Wednesdays) at 3:00 a.m. with the arrival of the products by ship, truck and plane from all over the world. Source: Takeshi Igarashi/Flickr

  • Inspecting Tuna in the 1960s at Tsukijij Fish Market, Tokyo. Source: Jay Bergesen.Flickr

  • A New Zealand Green Lipped Mussel Farm near Havelock, South Island, New Zealand. Source: Abaconda Management/Flickr