Plenty of Fish in the Sea?

achieving a sustainable future for fishing industries

Why do we fish?

Fisheries are needed in order to provide for a primary source of food for human populations and more specifically, coastal communities. This resource is also considered vital as it is a global commodity that provides jobs for more than 80,000 Canadians and contributes billions of dollars to the economy because of the substantial exports of fish products. However, unsustainable practice over the mid-20th century has depleted over 85% of fish stocks and left them to a point of collapsing. If actions that move towards a sustainable way of development aren't taken, there will be numerous implications.

Impacts of depleting fish stocks

Overfishing reduces biodiversity and causes an imbalance in the aquatic ecosystems as it completely eliminates almost entire populations of species. This allows other species lower in the food chain to flourish because there is no predator hunting them anymore. It can also work in the opposite way where it causes some aquatic life to die off because if the lower food chain species are overfished, the fish higher in the food chain have no source of food. An example of the alterations made to the marine life food chain can be seen with the overfishing of bluefin tuna, a top predator. As the global demand for tuna stays at high rates, the bluefin tuna is on the brink of extinction (96% reduction of the bluefin tuna population). Because they are a top predator in the food chain, wiping them out led to an overpopulation of the smaller fish they eat, meaning that the smaller fish like mackerel and herring began to consume even more. It also leads to increased algae growth and threatens the health of coral reef, both things that would have a substantial impact on the conditions of the water. Essentially, there is nothing to keep the lower food chain species in check without a top predator.


As well, many fish species are fished before they reach sexual maturity, so the population cannot repopulate at a rate that is faster or equal to the rate at which these fish are being taken out of the sea and harvested.


Another concern posed by overfishing arises from the methods used to catch the fish. Modern fishing mechanisms (trawling and longlining) are highly unselective and cover vast areas in order to be more efficient at catching the desired species. However, what this does is produce by catch as it hauls non-target species such as dolphins and turtles. Trawling leaves fragile ecosystems scathed as it removes the delicate sponge of the sea floor. To put this in perspective, it is estimated that 300,000 small whales, dolphins, and porpoises die because they become entangled in fishing nets each year. Overfishing would result in these avoidable deaths because now, even more boats would be out in the sea and employing the longlining and trawling methods to capture more fish.


The collapse of the cod and cod fishing moratorium, which has been in place since 1992 due to overfishing, have forced fishers to find an alternative to cod. While many turned to alternate fisheries (crustaceans), some have ended this way of life altogether due to virtually no healthy fish being found in the sea. The increased rates of unemployment brought on by this will threaten the economic welfare of many citizens. So while fishing is generally thought to generate a profit, over time, the exploitation of these resources lead to severe periods of depression of the fishing industry. As well, fishing is a central element in traditional diets of Africa and South Asian coastal nations. The declining fish stocks due to both illegal fishing and overfishing, makes fish less accessible for the citizens that need it the most. Without this vital food in their diet, many of these people would lose over 50% of their protein intake and suffer health problems.

Managing Fishing in a Sustainable Manner

An understanding of the aquatic environment and its resident species is required in order to make the harvesting of Canada’s aquatic resources more sustainable in the near future. Fish that have not reached maturity should not be caught because if they don't live up to reach sexual maturity, there won't be enough of them to reproduce at a rate that replenishes the population. Allowing the juvenile fish to survive will allow the species to repopulate so that their numbers will rise again. If this method is not employed, the population will dwindle and have an affect on the whole aquatic food chain. It's important to distinguish between the different species as some take longer to mature, such as the bluefin tuna, so fishing of those specific species would have to occur after longer time intervals so that the younger bluefins can age. Another simple step towards sustainability is to create/expand protected aquatic ecosystems to specifically protect threatened or endangered species.


Another way to control the exploitation of fish is to establish a quota on the total number of fish caught for all coastal fisheries. When determining this limit, it's important to ensure that this number is scientifically determined and constantly reassessed. Reassessing the limit on the catch is fundamental because for example, there might be thousands of cod swimming around in for the first 3 months of the year, but in the next 3, the population might begin to die off due to a natural force. So if the allowable catch value was constant throughout the first 3 months and the second 3 months, the population would have further decreased. Limiting the number of fish that can be caught will make fishing more sustainable because the resources aren't being over exhausted.


In combination with setting an allowable catch, providing fishers with intervals of times that they are allowed to fish would further make fishing more sustainable. This would give the fish colonies the timed needed to repopulate. An important thing to note is that short term economic gains and politics should not be considered heavily when setting the allowable catch, as that generally sways against sustainability of natural resources.


A country that implemented a few of the above measures is the U.S. In order to control the exploitation of coastal fishing, the U.S. made an amendment to the Magnuson-Stevens Fishery Conservation and Management Act (MFCMA) in 2007. This established annual catch limits (ACL) that are science based and take into consideration the ecological health and population of the different species of fish. The ACL must be at or below the acceptable biological catch (ABC) because anything exceeding the ABC jeopardizes the livelihood of the fish.


Monitoring and laws must be widely enforced to prevent the overkill of too many fish. More severe punishments for culprits that Illegally fish must be given, as illegal fishing accounts for an estimated amount of 20% of the world's catch. If the governments of coastal communities regulates the waters and removes illegal ships, there will be a greater population of fish. Apart from this, giving control to the local fisherman rather than foreign companies would solve the problem of overfishing. This is because it has been shown that the local fisherman only catch as much as they need and aren't fishing to the point where the fish are almost gone because they understand the patterns of the fish.


In order to eliminate the tremendous amount of bycatch of innocent animals that come with overfishing, alternative fishing methods must be used. The World Wildlife Fund has come up with alternative gear such as using circle hooks rather than J-shaped hooks as they are less likely to be swallowed by turtles. Trawling must be completely stopped as it destroys the sea floor and leaves too many untargeted species in harm.


Consumers must also be more aware of how and where their fish come from. By looking for labels by the Marine Stewardship council, the consumers show the fishing companies that they only eat fish that are caught in a sustainable manner. This would decrease the demand for fish that are caught using dangerous methods such as trawling, so the companies will begin to alter their methods once they realize that their demand is going low.


Overall, conservation of fish stocks should allow us to be able to keep harvesting fish in the future for other generations. At the current rate, it is apparent that fishing resources will run out unless proposed measures are taken to curb the rate at which we fish at.

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