Ahi tuna, belonging to the wider mackerel family Scombridae. They are large, deep-bodied, streamlined fish with large heads and eyes.
Bigeye tuna have a unique physiology which allows them to forage in deeper colder waters and tolerate oxygen-poor waters. Bigeye tuna are reported to tolerate ambient oxygen levels of 1. L and routinely reach depths where ambient oxygen content is below 1. L, largely due to the presence of blood with a high oxygen affinity. 105 cm in the western Pacific Ocean.
Bigeye tuna undertake a distinct diel shift in vertical behaviour, generally descending at dawn to deeper, cooler waters and returning to shallower, warmer waters at dusk. Typical vertical behaviour of bigeye tuna shifts when fish associate with seamounts, buoys and fish aggregating devices, with individuals remaining in surface waters. Results from tagging studies show that bigeye tuna are capable of traversing ocean basins, but can also show a high degree of site fidelity to some regions. Bigeye tuna primarily feed on epipelagic and mesopelagic fish, crustaceans and cephalopods. Globally, approximately 450,500 metric tonnes of bigeye tuna were caught by commercial vessels in 2012.
The bigeye tuna catch rates have also declined abruptly during the past half century, mostly due to increased industrial fisheries, with the ocean warming adding further stress to the fish species. Research indicates that increasing ocean temperatures are taking a toll on the tuna in the Indian Ocean, where rapid warming of the ocean has resulted in a reduction of marine phytoplankton. Most seafood sustainability guides encourage consumption of other types of tuna. In 2010, Greenpeace International added bigeye tuna to its seafood red list.
The IUCN Red List of Threatened Species. Pacific Ocean, ascertained from archival tag data”. Azores Islands determined with pop-up satellite archival tags”. Canadian Journal of Fisheries and Aquatic Sciences.
Feeding ecology and niche segregation in oceanic top predators off eastern Australia”. Simultaneous observations of tuna movements and their prey by sonic tracking and acoustic surveys”. Hawaiian Islands from archival tagging data”. Hawaii determined by Kalman filter analysis of archival tagging data”. Feeding partitioning among tuna taken in surface and mid–water layers: the case of yellowfin and bigeye in the western tropical indian ocean”. Statistiques des pêches et de l’aquaculture. Commission des Thons de l’Océan Indien”.
Stock assessment of bigeye tuna in the Indian Ocean for 2012″. Conservation and Management Measure for bigeye, yellowfin and skipjack tuna in the Western and Central Pacific Ocean”. Wikispecies has information related to Thunnus obesus. The End of the Line: How overfishing is changing the world and what we eat. BEHAVIOR AND PHYSIOLOGY AND THEIR RELEVANCE TO STOCK ASSESSMENTS AND FISHERY BIOLOGY’. These tuna steak recipes are the best ways to serve this meaty, buttery fish! Try it seared, grilled, in tacos and more.
Try ahi tuna seared, grilled, in tacos and more. 10 great ahi tuna steak recipes! Need a simple meal that’s restaurant quality? The flavor is melt-in-your-mouth meaty: with a salty, seasoned exterior and a buttery, raw interior. You’ll want to use sushi grade fish here.
Sear it up in a hot pan, and it’s one of the most impressive meals you can make. Tired of grilling burgers and salmon? Good, because here’s an incredible grilled dinner idea: grilled tuna steaks! Ahi tuna is rich and buttery. Seared perfectly on the outside, it tastes more like chicken or steak than fish! There’s nothing fishy about this tuna. Even better, it’s one of the quickest things you can cook.