Roland Seitre / Southern bluefin tuna (Thunnus maccoyii) in fish cage of fish farm, Port Lincoln, South Australia, Critically Endangered species. Wild caught fish are reared in large fish cages for maximum growth bef...

Mike Parry / Southern Bluefin Tuna (Thunnus maccoyii) school underwater, South Australia

Mike Parry / Southern Bluefin Tuna (Thunnus maccoyii) underwater, South Australia

Norbert Wu / Atlantic Bluefin Tuna (Thunnus thynnus) examinded with flashlights by buyers to determine the quality of the meat, Tsukiji Market, Tokyo, Japan

Norbert Wu / Atlantic Bluefin Tuna (Thunnus thynnus) underwater, Sardinia, Italy, Mediterranean Sea

Norbert Wu / Atlantic Bluefin Tuna (Thunnus thynnus) school in Mediterranean Sea, Sardinia, Italy

Alex Mustard / A school of mackerel (Scombridae) and a diver alongside a coral reef wall. Ras Mohammed National Park, Sinai, Egypt. Red Sea

Juan Carlos Munoz / Albacore / Longfin tuna (Thunnus alalunga) caught fish, tails on ice. Santona, Cantabria, Spain. August 2011.

Juan Carlos Munoz / Fishermen sorting Albacore / Longfin tuna (Thunnus alalunga) fish catch on dock in early morning. Santona, Cantabria, Spain. August 2011.

Juan Carlos Munoz / Fishermen sorting Albacore / Longfin tuna (Thunnus alalunga) fish catch on dock in early morning. Santona, Cantabria, Spain. August 2011.

Shane Gross / School of Skipjack tuna (Katsuwonus pelamis) are caught in a seine net off North Sulawesi, Indonesia.

Nick Hawkins / Atlantic bluefin tuna (Thunnus thynnus) jumping at surface after prey. Nova Scotia, Canada. October.