Natural Marine World Tidbits

Bigeye tuna by Tom Byrnes

A bigeye tuna in Cayman waters.

Bigeye tuna, Thunnus obesus, is a fast-growing and agile predator that can reach eight feet and 400 pounds.

Due to its high-fat content, it is the preferred sashimi tuna and the most-prized among tuna fishermen in the Atlantic northeast.

These fish are found worldwide in temperate and tropical seas, although they spend most of their time in the cool depths of 1,000-1500 feet. I hooked the one in the picture in 1,200 feet off South Sound. To my knowledge, this is the first bigeye ever caught in Grand Cayman.

What started in the Azores as a Portuguese line-and-pole fishery has evolved into a multination sophisticated fishing effort, which has decimated stocks of these once-abundant fish. As usual, the management body International Commission for the Conservation of Atlantic Tunas (ICCAT), continues to do a horrible job and the future of this magnificent species looks bleak.

Tom Byrnes is the owner/operator of Cayman Marine Lab. He acquired his Coast Guard Captain’s Licence when he was a teenager and worked as a commercial fisherman in his youth. He got his first diving certificate in 1974 with the YMCA. He has worked in the local dive industry for more than 35 years and has a PhD in marine biology.

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