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While many of us may think that over-fishing is only really a problem for fish, fishermen and those who like eating fish, there are many environmental side-effects caused by over-fishing and it can affect us all. Read on as we reveal the delicate balance of nature and how man’s actions are destroying this fragile equilibrium.

What is Over-Fishing?
As the name suggest, over-fishing is catching too many fish for the fish population to successfully maintain its numbers. If over-fishing occurs, the fish stock of a given population will dwindle, before eventually dying out. Over-fishing has occurred in recent decades because there are too many vessels, often with improved fish harvesting functions – such as bigger nets and dredging equipment - operating within fisheries. This is leading to considerable over-fishing of many fish species. So much so in fact that the UN’s Food and Agriculture Organisation (FAO) estimate that nearly 70% of fish stocks worldwide are ‘fully fished, over-fished or depleted.'

Over-Fishing: How it Affects All of Us
While overfishing has a terrible effect on fish-stocks and the livelihoods of those dependent on the fishing industry when fish stocks run out, there are also many implications for both humans and the wider natural environment, too. Modern day fishing techniques typically yield a considerable amount of bycatch – the term used in the fishing industry to describe other species of fish and marine life that are caught as a by-product of large scale fishing. Bycatch is not what the fishermen want to catch and are of little or no commercial value, but they nonetheless get caught in the nets and killed. For example, for every tonne of prawns caught by commercial fishing boats, three tonnes of other fish are believed to be caught as well. Dolphins are particularly susceptible to tuna fishing techniques also, with thousands killed annually.
Also, over-fishing not only has an effect on the stock of a particular fish species, over-fishing can have a significant impact along the food chain, too. For example, there is some argument to be made that over-fishing of krill – the small shrimp-like creatures that form the main diet of many whales, including the Blue Whale, may have contributed to the decline in the numbers of these marine animals.

Over-Fishing: The Jellyfish Affect

The destruction of fragile marine eco-systems and food chains as a result of over-fishing may also be having an effect in more unusual ways, too. Since the 1980s the number of stinging jellyfish inhabiting the world’s oceans has increased considerably, transforming the fisheries of areas such as the Gulf of Mexico, the Sea of Japan and the Mediterranean, as well as having a detrimental effect to many tourist destinations. Scientists are baffled as to what is causing such significant increases; however, human influence is increasingly being raised as having something to do with it. Factors such as increases in the temperature of the world’s oceans due to climate change and global warming and increased pollution levels have been cited as possible causes for the ‘swarms,’ but over-fishing too – removing jellyfish predators and competitors for food – has also been pinpointed as a potential reason for the continued increase in jellyfish numbers worldwide.

What you can do? Buying the Right Fish
Fishing, like all industries, is dependent on the needs and interests of consumers: fishermen only catch fish because they know they can sell their fish to consumers, who will pay to buy them. If you want to make a difference and protect fish stocks and the environment, there are several things that you can do.
The first thing to do is get educated. Did you know that most cod stocks are dangerously low, while Sole, including Dover Sole, is well stocked and believed to be sustainably farmed? As a consumer you can deliberately have an effect on fishing methods and the type of fish fishermen catch by widening the type of fish you eat.

Buying the Right Fish, At the Right Time
While the type of fish you eat is important, so too is the time of year that you buy certain fish. A quick rule of thumb is to try to avoid eating fresh wild fish caught during the spawning season of a specific fish species. This gives fish stocks the opportunity to grow in a more sustainable way. For example, you should avoid buying Atlantic Cod in February, March or April; Plaice in January, February or March or Mackerel from March to July.
You could also change your shopping habits further and only buy fish from supermarkets that have sustainable fishing policies in place: the more pressure put on businesses by consumers, the greater the likelihood of effective, lasting change taking place. Check at your local supermarket to see what their policy on sustainable fishing is like.
Over-fishing is a serious problem and one that could as yet have hidden, unknown environmental consequences further down the line. Take action now and check out our related links section to learn more about how you can get involved in protecting our world’s oceans and fish-stocks.