Action 265: Think about the source of your tuna fish

TunaDate: 22 September
Action: 265
Cost of taking action: £/$/€ NIL


From our guest author Halima Curran in Libya

Tuna fishing has done serious damage in the past; you can help us to avoid it in the future

Halima has seen some of the damage first hand, and writes for us with that experience

Quite a lot of people like tuna.

I million tons of Tuna are consumed annually in the US and Japan alone, the world’s two largest tuna markets.

TunaThe Japanese use it in sushi.

This consumption is despite the fact that, like many ocean fish, tuna contains traces of mercury. The US Food and Drug Administration even recommend that consumption of tuna should be limited, especially in the case of pregnant women.

Is tuna plentiful?

The days of plenty have ended.

The Bluefin tuna has been red listed as critically endangered, but it is still being caught (a lot of it illegally). Overfishing and the methods of catching tuna are two serious problems posing danger to fish stocks, the environment and the livelihoods of local fishermen.

Techniques and their adverse impacts

The two most common fishing methods used by large commercial vessels are long line fishing and purse seining, which also produce large amounts of wasteful bycatch (other varieties of fish which are hauled in with the tuna catch).

Long line fishing, as its name suggests, involves the use of extremely long fishing lines with shorter lines branching from them, all loaded with baited hooks. It is an effective method for catching tuna but it also catches other fish and seabirds. The poor birds usually drown.

Purse seining is used to catch yellowfin tuna in particular. A massive net is laid out in a wide circle which is then gradually drawn inwards, catching all the marine life inside. This is known to particularly impact on dolphins, of which thousands are killed annually in this way.

The nets and lines themselves are made of non-biodegradable monofilaments. Unfortunately they are often lost and can drift in the sea for years like deep sea monsters, entangling marine life and killing as they go.  Battery powered plastic beacons to help fishermen locate their lines and nets frequently come adrift, adding to the toxic waste already in the sea.

Bycatch can be 60% of the total catch!

These two fishing methods, with their extremely wasteful bycatch (which can total as much as 60% of the catch) also contribute to species loss.  Billions of fish are destroyed due to these methods, along with hundreds of thousands of sea turtles and cetaceans!

Already, one third of all sharks, rays and chimaeras are at risk of extinction.

The number of endangered and critically endangered species has more than tripled. Of course, climate change has also contributed to this loss, along with human destruction of marine life habitat, but overfishing exacerbates it considerably.


Overfishing by large vessels (many from France and Spain) has brought the Bluefin tuna to the verge of extinction and also depleted stocks of Albacore, Skipjack and Yellowfin to the point of being classed as ‘overfished.’

Living in Libya, which once boasted a flourishing tuna trade with boats and canneries, it’s very sad to see the decline.  The once plentiful tuna is now expensive, smaller tuna fish are being sold, and the spawning season – when tuna fishing is supposed to be prohibited – is ignored (this is obvious when one finds roe (eggs) when cleaning the fish).

Attempts are made to sell the bycatch to lessen waste, but people prefer the tastier tuna and, at the end of the day, the dead, unwanted fish are tossed back into the sea.

I have seen the resulting thick blanket of decomposing fish in the water myself.

Local fishermen in poorer countries use the ancient, more eco-friendly method of pole and line fishing.  However as stocks dwindle they often resort to the dangerous practice of blast fishing, also known as dynamite fishing or fish bombing. This is illegal but still common, even here in Libya; it destroys EVERYTHING – corals, larvae, the lot – and leaves sterile seabirds. This practice produces profits but only in the short term and in the end poverty results because the smaller family businesses simply cannot compete with the foreign giants.

What needs to be done?

Although the obvious thing would be to ban tuna fishing until stocks increased, we have to acknowledge that this is highly improbable. The following solutions could be adopted or enforced however:

  • no fishing during the spawning months
  • heavy fines for illegal fishing, including the confiscation of ships
  • very heavy fines/imprisonment/ confiscation of boats for the use of spotter planes to track tuna shoals, and blast fishing, both are illegal
  • the creation of a Blue fin tuna sanctuary in suitable waters
  • the creationof tuna fish farms
  • encourage people to eat less tuna
  • promote other sources of protein and omega-3 instead, e.g. certain seed/nut oils, purslane, etc

Take action

Hopefully just by reading this article you will think carefully about the source of the tuna you eat. Try to

  • ensure that you choose fish that is responsibly sourced, and that such claims are certified
  • reduce the amount of tuna you eat
  • avoid consuming the threatened bluefin tuna in particular


As well as her own personal experience in Libya, Halima cites the following online sources for this article:

You can read more from Halima or follow her on Twitter at @HRafferty1