What are the species of tuna?
- There are 8 species:
- Atlantic bluefin (also called Northern)
- Pacific bluefin
- Southern bluefin
What are the basic characteristics of the bluefin tuna?
- Located in the Mediterranean Sea; Iceland to the Canary Islands; and Newfoundland, Canada, to the Gulf of Mexico.
- Typically they swim from 1.74-4.5 mph to 9.20 mph. When chasing prey or to avoid predators, they swim up to 44-62 mph.
- They can dive to depths of 3,280 feet.
- Size for average mature adult:
- Length ranges from 6 ft 7 in – 8 ft 2 in; maximum 21 feet
- Weight 600 lbs.; maximum 1,600 lbs.
- In the 1970's the average weight was 1,200 lbs. and now the average is 600 lbs.
- They are” warm-blooded” – this keeps its core muscles warm (used for power and steady swimming).
- They can live up to 30 years, but few survive this long due to rampant overfishing.
- They eat herring, mackerel, hake, menhaden, squid and crustaceans.
- Their predators are orcas (killer whales) and sharks.
What is the state of bluefin tuna?
- Since the early 1900's when factory fishing was introduced, the bluefin numbers have been reduced by 90% and in the Mediterranean it is down to 97%.
- Between 1970 and 1998, there was 70% drop. This shows the rapid acceleration of the decline.
- In 2009, 72% decline in the Eastern Atlantic, and 82% decline in the Western Atlantic. In the same year, Monaco formally declared them as endangered.
- At a United Nations-backed conference aimed at regulating international trade in endangered species, the total ban on bluefin tuna fishing and trading was rejected on March 18,2010. The Convention on International Trade in Endangered Species (CITES) voted 68 to 20 with 30 European abstentions.
Who is fishing them?
- Australia, Cape Verde, Croatia, Cypress, Greece, Italy, Indonesia, Japan, Libya, Malta, Mexico, Oman, Panama, the Philippines, Portugal, Spain, Tunisia, and Turkey. Half are operating in the Med.
- Japan and Australia are the largest fisheries.
Who is buying the bluefin tuna?
- They are used for sushi, sashimi and steaks. They are prepared in sushi as hon maguro or toro (tuna belly).
- It is a $7.2 billion industry around the world. The largest consumers are Japan.
- The suppliers are marine fisheries, not fish farms.
Toxins in bluefin tuna?
- There are elevated levels of mercury and PCBs in bluefin tuna. It should be avoided.
Why is bluefin tuna crucial?
- Bluefin tuna matures slowly and they are less resilient to fishing pressure.
- As part of the ocean's ecosystem, they are needed for preys and predators in the oceans.
How are the bluefin tuna fisheries regulated?
- The International Commission for the Conservation of Atlantic Tunas (ICCAT) is an inter-governmental fishery organization responsible for the conservation of tunas and tuna-like species in the Atlantic Ocean and its adjacent seas.
- Unfortunately, the international organization managed the underreporting of juvenile catches and illegal fishing. The fishing takes way exceed the international quotas.
How are they caught?
- Overfishing with hi-tech commercial fishing fleets and rampant illegal fishing will make the bluefin populations vanish from Mediterranean waters. They are in great danger.
- The bluefin tuna were traditionally caught with traps. Currently, purse seines are used instead and then the fish are transferred to tuna farms in cages to be fattened up.
- They are caught with purse seines, longlines, troll lines, and trap nets. Sometimes harpoons, handlines, pole-and-line, and nets.