Since the start of commercial exploitation Atlantic Bluefin Tuna (Thunnus thynnus) population has dropped 85%. Eight species of tuna exist worldwide but they are not all the same, the Atlantic Bluefin Tuna is one of the largest and fastest and weighing up to 1500lbs. They continue to grow all of their lives and if humans had not become so efficient at catching them they would grow to weigh up to a tonne. Vital to the balance of the oceans food chain Thunnus thynnus is a top marine predator. Their daily diet contains a mixture of small fish such as anchovies and mackerel.
Once a year thousands of Atlantic Bluefin Tuna migrate to the Mediterranean Sea to breed forming spawning aggregations, with females laying 10 million eggs each spawning period. The lifespan of wild Bluefin Tuna is estimated between 20 and 30 years, tuna that is caught and placed into captivity are kept for a short time before fattened for harvesting only living a short life span. Fish farms are wasteful using 25kg of fish to fatten the Tuna by only 1kg, because we have created such a distorted ecosystem other fish stocks are also crashing.
The law states that a Bluefin has to weigh 30 kg and at least spawned once before slaughter. There are strict quotas and size limits and the fisheries are rod and reel and harpoon. Tuna are sexually active at the age of 5 but in reality the fish are illegally caught and fattened in farms. In the Eastern Atlantic it is a massacre and the governments are too weak to stop it.
This fish gold used to be considered trash fish and was called by fisherman the ‘Horse Mackerel’ and had no value until the lust for sushi from Japan began and this is something the human race can now not sustain, the Atlantic Bluefin Tuna is now the most valuable fish on the planet.
Blue fin tuna has been fished sustainably for thousands of years yet the sustainability of Atlantic Bluefin Tuna is now potentially at risk due to overfishing in the Mediterranean Sea, bringing fortunes to fisherman on popular docks around the world, with a single fish auctioned off for over $1 million.
Commercial fishing was introduced in the 1950’s and an increase of interest in Bluefin from Japanese high end sushi markets began. Due to lack of control of its fisheries this has led to increasing numbers of illegal fishing, causing the decline in the population of Atlantic Bluefin Tuna. There is no enforcement of the international fishing laws and most of these catches are illegal. If bf becomes extinct it will have a major impact on the marine ecosystem, as this absorbs most of global warming and give us 80% of our oxygen. Insuring a full recovery of this species is needed and laws should be placed urgently, no more overfishing or illegal fishing.