Fishing for a Friendlier Future

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.