Sharks no longer are the kings of the seas. What were once fearsome and mighty ‘monsters’ that ruled the aquatic depths are now reduced to mere prey by fishermen, caught in large nets and having their fins lopped off, before being hauled overboard to sink to the ocean floor and drown. This is a problem not only exclusive to sharks but also to other forms of marine life such as turtles and seabirds. Evidently, there is a problem with our fishing methods, and their impacts are deleterious on the marine ecosystem. We are overfishing, and our destructive methods wreck marine flora and fauna unfortunate enough to be caught in its path.
Fishermen are fishing in oceans on a large scale, such that fish are being caught at a faster rate than they can reproduce. As a result, there are insufficient fishes in the ocean to breed to replenish the population in time, leading to many fish species being considered threatened or endangered.
Bottom trawling leads to the devastation of the sea floor, destroying coral habitats and uprooting sea plants. It may also disturb sedimentation, which suffocates bottom dwellers. Credits: Marine Stewardship Council (Source:https://www.msc.org/what-we-are-doing/our-approach/fishing-methods-and-gear-types/demersal-or-bottom-trawls )
No longer do we see fishermen in their tiny boats using fishing rods to catch fish, instead we see huge mechanical ships armed with advanced fishing gear such as sonar to pinpoint large schools of fish quickly, and gigantic nets that can abduct large amounts of fish at any time. In particular, one devastating fishing method used is known as bottom trawling, where a large weighted net that stretches to the seafloor is dragged by large commercial trawlers, catching any and every unfortunate creature in its path.
Credits: Monterey Fish Market (Source: https://www.montereyfish.com/finfish-techniques )
Gillnetting is also another insidious method used by commercial fishing boats. They can be anchored to the seafloor or drift afloat on the ocean surface. Large nets that are kilometres in length and up to 200 metres in height may appear to be environmentally friendly, as small fishes can swim through the gaps in the net, while larger fish are caught by their gill covers when they try to swim out of the net. However, such an indiscriminate fishing method also catches sea birds, sharks and seals, as the wings, fins and flippers of such creatures may get entangled in the net.
The problem of overfishing, therefore, has impacts not only on the ocean ecosystem, but on humanity as well.
This is the amount of bycatch in a shrimp trawler. There seems to be fewer shrimps compared to other animals! Credits: Eliott Norse/Marine Conservation Biology Institute (Source:https://ocean.si.edu/conservation/fishing/bycatch-shrimp-net )
Firstly, traditional fishing methods lead to a gargantuan amount of bycatch each time. Birds may accidentally get trapped by fishing nets when they dive for food while seals that forage on the seafloor drown due to the lack of air as they get entangled in nets. Shrimp trawlers are the biggest culprits of bycatch, responsible for over 25% of total estimated discards, which is equivalent to 11 million tonnes of fish yearly. However, they only produce 2% of all sea food. For every 1 kilogram of shrimp caught, up to 15 kilograms of bycatch is caught and thrown away.
Nomura jellyfishes have invaded the coast of Japan, impeding fishers while providing no commercial value to them. Credits:Niu Fisheries Cooperative (source:https://www.eurekalert.org/multimedia/pub/42784.php?from=210204)
This disrupts the natural food web and leads to a loss in marine biodiversity. For instance, overfishing of turtles, tuna and swordfishes in the coast of Japan has caused the jellyfish population to thrive due to a lack of natural predators. This worsened the already limited supply of fishes, as jellyfishes feed on fish eggs. Local fishermen are also affected, the lack of fish diversity near to the coastline would mean that they have to venture further out to sea to fish in more productive waters, where the weather is more volatile and render them more vulnerable to rough seas. This threatens the livelihoods of local fishermen as they are unable to compete with large commercial fishing companies as well.
Eventually, these problems will trickle down to us consumers. Fish is a good source of protein and remains integral to many diets and cuisines worldwide.The dwindling supply of fish may mean that we have fewer food choices in future. In fact, if we don’t stop overfishing, we may potentially not have any fish left for sushi by the year 2048!
Enter sustainable fishing. Sustainable fishing is the practice of harvesting fish at a sustainable rate, leaving enough fish in the ocean to replenish its supply. It involves no damage to ocean habitats and ensures that those who depend on fishing can maintain their livelihood. As presented, allowing fishes to breed and replenish their populations prevents overfishing to the point of extinction!
Sustainable fishing methods include trolling and the creation of more marine reserves. In trolling, multiple rods are used to catch fish on a moving boat, giving the impression that the bait on the fishing rod is moving and hence resembles the prey of the fish. Such a method has a very low bycatch level as fish are caught individually and can immediately be released if it is not the targeted fish desired by fishermen.
The trolling method allows for rapid catching of fish, with the added advantage of allowing catch-and-release, reducing the amount of bycatch. Credits: Les Hala (Source:https://www.hawaii-seafood.org/hawaii-fishing-industry/trolling/)
Furthermore, the creation of marine reserves where fishing is strictly banned can significantly help to restore the fish population by providing creatures with a safe habitat to breed. Yet, not even 10% of the world’s oceans are protected. Merely 2.6% of the ocean is considered fully protected, where little to no human activities are allowed. 3.2% of the ocean is considered slightly protected, although mining, drilling and fishing can still occur. Clearly, more protection needs to be enforced to help with conservation efforts.
However, that does not mean that no progress is being made on the development of marine reserves. Recognising the gravitas of a dying marine ecosystem, world leaders, scientists, and many non-profit organisations have called for greater awareness and actions to develop marine protected areas so as to improve the health of the ocean.
Malpelo Island is home to more than 400 species of fish and a rich biodiversity of sharks, often topping the list of the best diving sites.
Credits: Sarah Morlock (Source:https://blog.padi.com/dive-malpelo-island/)
Since 2008, National Geographic’s Pristine Seas Project has led to the creation of more than 20 marine reserves. It is estimated that they protected more than 6 million square kilometres of the ocean, where strictly no fishing, mining or other intrusive activities can take place. One such protected region is Malpelo island, Columbia, where the Pristine Seas team cooperated with the government to double the size of Malpelo’s Flora and Fauna Sanctuary out to 300 miles from the mainland’s coast. Today, Malepo is one of the largest no-fishing zones in the region, totalling 20,000 square miles.
Community Fish Refugee ponds in Cambodia aim to support the livelihoods of local fishers and farmers, as well as promote fish as a nutritious source of protein in the diet of the locals. Credits: Worldfish (Source:https://www.worldfishcenter.org/pages/community-fish-refuges/ )
Similarly, WorldFish is an international nonprofit organisation that seeks to promote sustainable aquaculture. One of their projects involves scaling up the creation of community fish refugee(CFR) ponds in Cambodia to provide a safe haven for fishes during dry spells. In wet seasons, the floodplains and the CFR ponds are connected and farmers catch as much fish in the floodplains as they like. During drier seasons, the fish migrate back towards the CFR ponds as the water level recedes, and the pathway between the floodplains and the CFR pond is disconnected. This helps prevent the overfishing of the local fish population by providing time for them to grow and replenish themselves as no fishing in the CFR ponds is allowed, making it similar to a mini marine reserve.
Closer to home, Fishery Networks is a local organisation in Singapore that advocates for greener fishing practices. They help seafood companies to track food safety and legal compliances and assist in the development of sustainable fisheries in Southeast Asia. For instance, they advocated for crab traps with escape hatches rather than gillnetting as a fishing method in Indonesia to allow undersized crabs to escape and grow, rather than merely catching all crabs regardless of size, which may not be productive when selling them.
The downloadable WWF sustainable seafood guide helps consumers make responsible seafood choices when shopping. Credits: WWF Singapore (Source: https://www.wwf.sg/get_involved/sustainable_seafood/ )
Individual consumers can also do their part to help support sustainable fishing. By voting with our wallets and supporting fisheries that obtain their catch via environmentally-friendly methods, we may encourage more fisheries to adopt more friendly methods to fish! For instance, WWF Singapore developed a simple guide available on their website that advises consumers to pick fish that are green or yellow-rated, which indicate that such fish are more sustainable and at less risk of endangerment due to overfishing. This would help consumers make more informed decisions when purchasing seafood, influencing the seafood market by supporting sustainable catches! Reducing our seafood consumption and supplementing it with plant-based seafood or seaweed would also greatly benefit fish populations.
For a better future for fish, and for ourselves, it is crucial that we act now to save our fish!