Farming and Fishing

Commercial fishing in large quantities depletes vast amounts of wild fish, but it is an important part of the human diet and livelihood for many people. So, to minimize disruptions to the environment, people's income, and human food chains, it is imperative to make it as sustainable as possible. It's possible to help save wild Populations by introducing fishing quotas, limiting net size, and using fish farms, but these methods don't come without their downsides.

So, let's dive into farming and fishing!

Sustainable Fishing and Farming

Fish is an important source of protein for human diets. Many Populations have survived off fishing. But in recent history, massive commercial fishing ships occupying the oceans where they catch many of the wild edible fish have resulted in dramatic declines in fish stocks.

If this uncontrolled overfishing continues, it has the potential to lead to:

• Less edible fish, which would be detrimental to those who rely on fish as both a main food source or an income source

• Certain species of fish completely disappearing in specific areas or going extinct, like bluefin tuna in the Mediterranean, cod in the northwest Atlantic and sole in the Irish sea and English channel.

• Food chain disruptions are capable of affecting many other aquatic species

It is therefore essential to maintain fish stock levels so that breeding can continue and the fish can replenish their populations.

Many have spoken out about the issues surrounding overfishing. Some restrictions have been put in place to help conserve fish populations. These more sustainable approaches include controlling the size of the net and introducing strict fishing quotas.

Increasing the gaps in the nets used for fishing can help in the following ways:

• Smaller juvenile fish (of the species being caught) are able to pass through the larger gaps in the net and live on till breeding age. So they are able to reproduce before they are caught, meaning the species has the potential to replenish.

• Less unwanted species are accidentally caught. However, the issue with this is that larger unwanted species are often still caught and simply discarded.

  This is still a major problem that needs to be addressed as the populations of these larger species are reducing!

Fishing quotas were also introduced. They regulate the particular size and quantity of a fish species that can be caught in a given area at a given time, like during the breeding season. Although these quotas can substantially reduce the number of trips fishermen make and therefore limit overfishing, it has its problems.

• Once fishermen are over their quota limit, they simply throw away any excess back into the sea (by this point, the fish are already dead) - this doesn’t help to maintain fish stock.

An alternative to catching fish in the wild is creating sustainable fisheries or fish farms. Here, the overall fish stock does not deplete as the number of fish caught does not exceed the number of fish born.

Introduction to Fish Farming

Fish farming, sometimes called pisciculture, is a form of aquaculture where large numbers of fish are raised in seawater or freshwater artificial enclosures or tanks. These fish are efficiently reared to turn their food into fish protein, predominantly used for human consumption.

Types of Fish Farming

Since farmed fish are kept in tight enclosures to limit movement, the conditions of their environment and the health of the fish are closely monitored and controlled as per the methods mentioned in the table below. This helps to ensure high yields of rapid growing healthy fish.

Benefits of Fish Farming

Overfishing is detrimental to wild fish stocks. More sustainable approaches like introducing fishing quotas, controlling net sizes and use of fish farms are ways to help prevent overfishing.

• The means to maintain water quality - many of the fish in the wild are subjected to a significant amount of heavy metals (like mercury) and other pollutants. This is ultimately consumed by humans and can lead to significant health problems.

• The ability to keep out competing species and protect against predators - allows for maximum yield.

• Being able to selectively breed fish - so that the fastest growing and highest quality fish can be produced.

Disadvantages of Extensive Fish Farming

Unfortunately, fish farming poses a few drawbacks, particularly regarding the surrounding environment and the health of both farmed fish and wild stocks. These disadvantages include:

• An increased risk of disease - since they live in such tight confinement, the spread of disease is high. This also poses a risk to wild stocks, particularly for open-pen fish farms, as they can be infected too.

• In order to control the spread of infectious diseases, Antibiotics are given, the water is sterilised, and pesticides are used - this can lead to antibiotic resistance and can cause fish to be mineral deficient (since their immediate environment is void of any).

  Antibiotic Resistance will likely become a serious public health crisis in the coming years. Antibiotics have become a staple of modern medicine and Agriculture in the last century, but their overuse is becoming very problematic. Check out the article on the Uses of antibiotics to learn more!

• A threat of Genetic Disorders - as many of the fish are selectively bred, they are likely to be closely related. This reduces variation and increases the risk of Genetic Disorders and susceptibility to infectious diseases.

• Eutrophication of the surrounding water - fish waste is actually used as a fertiliser for some crops (because it’s nitrogen-rich). Since this has to be removed regularly, it is often dumped in the surrounding water, causing dead zones due to an overgrowth of Algae and other aquatic Plants. Eventually leading to a decrease in Biodiversity.

• Other potential damage to wild fish stocks - some fish are fed high-protein diets, this is usually made up of other fish, usually caught from the wild. Additionally, escaped fish from enclosures have the potential to be invasive in the wild, since they are usually bred for fast growth.