We all know that rapid industrialisation and technological advancement in the last few decades have caused severe environmental consequences, but one issue that many people have yet to realise the importance of is the alarming decline in the population of fishes. It’s not just the fishes that we commonly find on menus but all types […]
We all know that rapid industrialisation and technological advancement in the last few decades have caused severe environmental consequences, but one issue that many people have yet to realise the importance of is the alarming decline in the population of fishes. It’s not just the fishes that we commonly find on menus but all types of exotic species too that are facing a large decrease in numbers due to climate change, habitat destruction, pollution, acidification, and, most importantly, overfishing.
Simply put, overfishing is when wildlife is taken from the sea at a rate that is too high for the fishes to reproduce and replace themselves. In the mid-20th century, fishing capacity was increased due to international efforts to increase the availability of protein-rich foods, and people got used to getting a variety of fish species at affordable prices. Studies have shown that the amount of fish eaten now is four times that of fish eaten in 1950.In fact, in 2011, global fish consumption reached as high as 17 kg per person per year. Recent reports suggest that there are fewer than 100 cod left in the North Sea who are old enough to create offspring.
One of the most important species being victimised is sharks, whose numbers have decreased by 80%. One third of the population of shark species is at risk of extinction. Depletion of sharks can have severe repercussions of its own, like increase in population of smaller fishes further down the food chain which in turn would case a large drop in the population of algae and other small marine plants that fish feed on. Any change in the food chain can completely damage the carefully balanced aquatic ecosystem.
State subsidies are definitely one of the major reasons that overfishing continues. A point is reached where the yield of fish after the decline in their population is too low for the fisherman to profit economically, which might have stopped them from continuing to exploit marine life were it not for the state subsidising their individual operating costs. More than 10 billion USD are given to fishermen worldwide as subsidies.
Moreover, increasingly efficient fishing methods such as bottom trawling, ghost fishing, purse seines, and fish aggregating devices (FADs) have completely wiped out fish from large areas of the Mediterranean and North Sea, and these areas are now practically deserts. These fishing techniques also kill a vast number of corals, sponges and other marine organisms and devastate the ecosystem. Trawlers sometimes accidentally catch seabirds. The number of seabirds that get killed annually by being caught in fishing lines is in six digits.
It is obviously impractical and highly unfeasible for industrialised countries to go back to using traditional procedures for fishing. So what are some of the possible solutions?
One alternative is to turn from hunting-gathering to farming, i.e. to farm fish. Aquaculture is actively being practised in several countries like China and Scotland. While it could be an answer, it creates a lot of problems of its own. Farming wild fish like salmon results in overfishing of the smaller breeds that are fed to these as forage fish, since each of the large fish eats about twenty times its own weight in the small varieties. Additionally, many farms such as salmon farms are typically located in coastal ecosystems which then get polluted by the run-of. The manure also fertilises algae in the oceans which leads to a reduction in the amount of oxygen available to other species. Farmed fish also become breeding grounds for parasites and infections.
Another solution is to implement policies that allot quotas to each fisherman in the form of individual catch shares instead of everyone trying to grab as much as they can. It has been suggested that quotas be set by individual governments according to the yield available in surrounding water bodies. There should be strict quota compliance. Fish can be tagged to make sure they are from a legitimate source. The fishing vessels should be tracked to make sure no one fishes in illegal areas.
In areas where the population decrease of fish is extreme, the only answer is to create protected areas or reserved areas. Currently less than 1% of the ocean is protected although it has been agreed to be raised to 10% by 2020. Australia, the Pacific islands, Britain and New Zealand have already made efforts in this direction. Solutions to prevent the death of seabirds include using weighted lines and lines that have flapping streamers can be used to scare of birds. These methods have already proven to be effective where they are used, reducing deaths of seabirds by about 85-90%. Bottom trawling has already been banned in a number of countries.
The World Bank declared estimated that the global fishing effort needs to be reduced by 44-54% to attain maximum economic yield and it has calculated that the loss of future net benefits due to overfishing is around 50 billion USD annually. While illegal fishing and unsustainable harvesting persist, there is hope in many regions, with scientists claiming that aggressive fisheries management and better enforcement of laws regarding catches can restore stocks.