Impact of a can of tuna

The Impact of a Can of Tuna

Tuna is a hugely popular type of fish that is eaten by hundreds of millions of people over the world. It is tasty, healthy and, in the case of canned tuna, an extremely convenient option for lunch. On the other hand, the convenience of this particular type of fish often clouds our thinking about how it actually got to our supermarkets in the first place. This article will explore the less positive sides of tuna and the impact it has on our ecosystem.

The ecological impact of tuna fishing

According to the WWF, the popularity and thus demand for tuna is rising rapidly all over the world, prompting fishermen and suppliers to meet market demand and putting ‘enormous pressure on the highly endangered and sometimes already collapsed marine ecosystems and fish populations’. The quantities of several varieties of tuna, including skipjack, yellowfin, albacore and bigeye are decreasing at a worrying pace, with some of them already labelled as vulnerable or near to extinction.

The increasing demand is not helped by the ineffective management of tuna fisheries, with fishing vessels increasing worldwide despite the tuna population remaining the same. The vulnerable status of many types of tuna could result in serious ecological disaster in the world’s tuna fisheries; tuna are predators, and overfishing them ‘upsets the ecological balance of the global centre of marine biodiversity’ (WWF). On top of this is the added threat of illegal pirate fishing, something which threatens the sustainability of global tuna stocks and the safety of regional fisheries. This results in scientists being unable to assess the health of tuna stocks, thus interfering with worldwide compliance regulations.

Finally, there is the added ecological disaster of other marine animals, as well as many birds, who are caught in the crossfire of mass tuna fishing and slaughtered as by-product in massive numbers annually.

Inhumane fishing methods

Commercial fishing obtains fish through efficient but often cruel methods. There are several methods of fishing, many of them inhumane, inefficient and harmful to the oceans. Here are the main methods used to catch tuna:

  • Longline fishing – long fishing lines with hooks attached. They catch tuna but also catch other animals, including dolphins, turtles and birds. The hooks are non-biodegradable monofilaments, and lines often get lost in sea, both of which kill marine life and create pollution.
  • Purse-seining – large nets to capture the animals. Here there is also significant bycatch of other marine life. Regulations are in place to prevent this, but thousands of other animals are still caught and slaughtered annually.
  • Fish farming – where the tuna are kept in fishing farms. Tuna are large fish, ranging on average from 1 foot to 14 feet – too large for a farm. Apart from the lack of space, the tuna are force-fed until suitably grown for slaughter.
  • Pole catching – traditional pole and line fishing, or bait-boat fishing. The fish caught using this method are sold mainly in local markets and not processed.

It is worth noting that the ruthlessness of commercial fishing, having depleted fish populations, has forced fishermen into using less sustainable methods of fishing in order to continue to support their communities.

Impact on climate

The impact of the commercialisation of fishing on the climate is often overlooked. The overfishing of the world’s fish, including tuna, has a very real effect on the biodiversity of all our oceans, threatening not only the tuna and other larger animals caught as by-product, but also smaller sea creatures and plants which rely on a cleaner ocean and climate to survive.

Elsewhere, a factor which is often overlooked are the pollution and greenhouse gases that are emitted throughout the production and transportation of the fish to different areas of the world. This is the case even with seemingly sustainable methods of fishing, such as pole-pole catching; although this is more humane to the animals, the amount of fuel used still adds up, still ultimately being detrimental to the climate.

These are all very real concerns for the world’s oceans, affecting not only tuna populations but marine biodiversity as a whole. It is true that a tin of canned tuna can be a quick, easy and cheap option for consumption, but perhaps the benefits of this don’t outweigh the risks. Help us tackle the impact of a can of tuna by supporting organisations to better manage the fishing of tuna, and not buying canned tuna while many species are near-depleted. The world can be changed for the better. But it all starts with us.