Wild Tuna vs Farmed | ATUNA
- ️Wed Apr 24 2013
| Wild tuna | Farmed tuna | |
| Volumes Globally | 5.6 Million Ton (99,9%) | 5.544 Ton (represents only 0.1% of the wild catches) |
| Available species | Skipjack , Tongol, Albacore Yellowfin, Big-eye,and Bluefin (More info species guide) |
Bluefin (Southern, Northern and Atlantic Bluefin tuna) Yellowfin farming only experimental |
| Living environment | Living in the high seas – swimming freely – their entire life span | Living in circular floating cages in coastal areas – usually for no more than one year |
| Feeding behavior | Very variable, natural, depending on migration pattern, they prey available on the spot and the characteristics of the eco-system. | Based on wild fish sardine, squid and mackerels. This involves that these fleets go for fishing these wild species, and then transport them frozen to farms in order to provide feed for fattening the bluefin. |
| Sizes | Available in all sizes | Bluefin between 60 and 100 kgs |
| Weight conversion rate | Fed naturally – irregular pattern | 15.8 Kg of feed needed for the tuna to gain 1Kg of body weight |
| Fishing method | Purse seiner on FADs, Purse seiners on free schools (Unassociated), Purse seiner associated, Pole & line, Hand line and Long liners. |
Catching by purse seiners – wild bluefin is kept alive within the net and then carefully transferred into cages or pens for fatting in floating cages in the ocean. Recently there are 2 centers for breeding Bluefin tuna from fertilization to maturity in captivity (the closed cycle) for Bluefin in Japan and Spain. Experimental research in Yellowfin hatchery in Panama. |
| Status of the tuna stocks | Only the big-eye tuna species in the Pacific approaches overfishing | Overfished globally |
| Sustainability claims | Some fisheries for Albacore, Yellowfin and Skipjack have been MSC certified | Not yet possible |
| Pollution and contamination | No negative impact; fully in balance with the ecosystem | * High pollution comes from solid waste (droppings and unconsumed feed) onto the sea bottom in coastal areas and dissolved nutrients into the water column.
* Use of chemicals that include antifoulants to keep cages free from colonial algae and animals; and therapeutants to deal with disease and parasitism. |
| Energy use (carbon footprint) (2009) | *Purse seiner (Skipjack and Yellowfin) 368 liters of fuel per live weight ton of landing.
*Pole & line (Skipjack and Yellowfin) 1485 liters of fuel per live weight ton of landing Average fuel consumption varies slightly by ocean. |
*Purse seiner (Bluefin) estd. 400 liters of fuel per live weight ton + fuel spent in catching bait (sardines, mackerel and squid)
*Catching baits |
| Availability – Fishing areas | All oceans worldwide | Farming areas : Mediterranean sea especially in Spain, Malta and Croatia; South Western Pacific ocean in Japan and Australia Central Eastern Pacific ocean in Mexico |
| Markets | Fresh, frozen and processed (canned, pouches, glass jars) Consumed globally |
Fresh (sashimi and sushi) – 90% goes to Japan. Frozen (Ultra Low Temperature minus 60 Celsius) also mainly Japan. |
| Nutritional value | Very similar content of: Protein, sodium, carbohydrate and total fat. | Farmed Bluefin has an exceptional high fat content |