Hundreds of kilometres from land and at least eight kilometres above the sea floor, I gaze in awe at the scene around me. I know that I am nowhere near a coral reef, yet this is the picture that’s being painted by countless triggerfish, golden trevally and rainbow runners who have all gathered in the same place as if answering some undersea call to arms. But despite their numbers, they are no match for what has actually drawn them here. By day’s end, these unwitting creatures will be in a deep freeze, victims of a man-made mechanism known as Fish Aggregating Device or FAD.

Made from steel drums, ropes, chains, nets, logs, buoys or an array of other objects, FADs are hardly an unusual sight in international waters these days. I swim towards a bamboo structure and I am amazed by what looks to be the oceanic food chain in full-working order  – ironic given that the FAD’s very purpose is to facilitate the removal of the species from the seas and, thereby, from the food chain. I marvel at the schools of rainbow runners about me, while yellowfin tuna and even sharks accompanied by pilot fish pass underneath. In the distance, small fish congregate around the central line. Further away from the line, the fish increase with size, all with a common goal: dinner. Sharks now circle the FAD’s colourful line, followed by hundreds of smaller fish, as if knowing the big kid on the block will clear a path to the prize.

As I surface, reality hits in the form of a Japanese purse seiner fishing vessel not far away. It brings home the hard truth of the dream-like scenario I had witnessed beneath the ocean’s surface just moments earlier. To catch fish using FADs however, requires more than just the device itself. The FADs are part of the fishing process that began in the late 1950s when purse seine tuna fishing started replacing the pole-and-line technique that had been used for decades. Named after the purse shape that is created by encircling the FADs with a net, the technique had a much higher catch rate and a broader range of operations than pole-fishing, successfully increasing the take of valuable fish like tuna. However, the process also had an unforeseen consequence. As is now widely known, schools of tuna were being encircled by the nets along with large pods of dolphins. Many of these marine mammals were subsequently killed in the operation that targeted the tuna and discarded the dolphins.

Fish school around a fish aggregating device (FAD) in the Western Pacific Ocean

Fish Magnets

The FAD was born when the fishing industry discovered that some species of tuna collected under natural floating objects like tree trunks, branches, kelps, things discarded by humans, buoys, crates, wooden planks, barrels and the like. So effective were the devices that, for many years there were purse seine fisheries in all oceans using floating objects as fish attractors. According to Martin A. Hall, principal scientist at the Bycatch Programs Inter-American Tropical Tuna Commission, more than half of all tuna catches by purse seiners today are taken on FADs.

Although much of the tuna now sold is “dolphin-safe,” the fisheries – especially those using FADs – have sparked a real problem within the marine ecosystem and primarily for the tuna stocks themselves. According to Sari Tolvanen, Oceans Campaigner for Greenpeace International, up to 10 percent of catches on the purse seiner FADs are unwanted species such as sharks, turtles and juvenile tunas as well as other fish species. This had been especially detrimental to the bigeye and yellowfin tunas. Their stocks are now in sharp decline across all oceans, as the juveniles of these species are caught by FAD fisheries in large numbers before they have a chance to breed.

Alternatively, skipjack tuna could be caught by the pole-and-line method in areas where there are sustainable baitfish resources available. This method is well-suited for the use of coastal communities in tuna-rich coastal states and would also allow these people to participate in the fishery who cannot afford to operate expensive purse seine vessels. The boats can also set their nets on free-swimming schools of skipjack tuna that do not associate with dolphins. These schools contain less of other species and juveniles of bigeye and yellowfin and is, therefore, a much more advisable way of catching tuna than using the deadly FAD fish magnets.

Schools of oceanic trigger fish circle a fish aggregating device (FAD) in the Western Pacific Ocean

The end of the line

Seafood has always been an integral part of the human diet and people have come to regard the oceans as an inexhaustible source of food. However, the world’s oceans are now in crisis. We are now seeing a steep drop-off of valuable fish stocks and many endangered marine species. Over the past fifty years, rapid technological advances such as stronger and faster boats, on-board refrigeration, sonar and satellites to track fish have led a huge expansion of fishing. Poor fisheries management, illegal fishing and destructive fishing methods such as bottom-trawling, cyanide, dynamite and FAD fishing has harmed untargeted species. It has also produced massive unintended catches of juvenile fish and other precious marine species that are often thrown overboard dead as freezer space is reserved for high-value species. This collateral damage is known as “by-catch”.

According to WWF, the current world fishing fleet is 2.5 times bigger than that which natural fish stock can support. This situation is not only unsustainable for the fish; it’s also uneconomical as these fleets compete for the limited supply of fish left in the oceans. That makes fisheries one of the worst-performing industries with an estimated US$50 billion wasted annually – not to mention the potential for many fish species to eventually disappear entirely from our tables.

 

Endless appetite for seafood

It is the insatiable and indiscriminate market demand that is ultimately killing our oceans. Seafood is increasingly seen as a healthy choice and the popularity of Japanese-style fine dining is only serving to whet our appetites for seafood. It is of utmost importance that consumers, seafood restaurants, supermarkets and fish wholesalers urgently take our share of responsibility to ensure fish for the future. By eliminating the most-threatened species such as bluefin and bigeye tuna, tuna caught with the use of FADs, sharks and prawns from the menus and replacing them with legally, sustainably and equitably caught products such as pole and line-caught skipjack tuna, markets can take the reins in furthering ocean conservation. As consumers, we can do our part by asking about the sustainability of the seafood we consume and demanding products that have been caught with respect to the oceans. This is paramount in bringing about desperately needed change in our oceans.

Taken from Scuba Diver Issue 3/2011, text and images by Paul Hilton

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