When people tell you not to eat Tuna because it will be fished out of existence, please refer them to the writings of the Greek philosopher Aristotle, who mentioned bluefin tuna in 350BC in 'History of Animals.' Tuna has been with us for a long time!
Pliny the Elder (A.D. 23/24–79), an ancient Roman author, naturalist, and philosopher, wrote about tuna and even recommended eating tuna to treat ulcers.
Historians also claim that the bones of tuna fish have been excavated from prehistoric sites that date back to the Stone Age.
Fishing for tuna is an ancient practice. Cave paintings near Sicily provide the best evidence that humans have been fishing for tuna for a long time. The paintings feature bluefin tuna and date from around 9200 years BCE. Archaeologists believe tuna was actively fished in the Mediterranean and have found evidence in Greece, Croatia, France, and Spain. Tuna has been a staple in Japan and the Pacific Islands since the 18th and 19th centuries, and historians say that tuna fishing is at least 2,000 years old in the Mediterranean.
Tunas come in many sizes. Western Atlantic bluefin tuna are the largest of the Atlantic tuna species. They can grow up to 13 feet long and weigh up to 2,000 pounds! They live 20 years or more and generally don't only spawn once they are eight.
Atlantic skipjack tuna are among the smallest, weighing 40 pounds and measuring around 3 feet long. They grow up fast, spawn when they are one year old, and have a relatively short lifespan of 7 years.
Tunas are speedy swimmers. Tunas are fast swimmers thanks to their unique torpedo-shaped bodies, smooth skin, and streamlined fins. Albacore tuna can swim faster than 50 miles per hour. This helps them catch prey, avoid predators, and quickly cover a lot of ground during annual migrations.
Tuna maintains a body temperature higher than the water surrounding them. Some tunas—like bluefin tunas—are warm-blooded, like mammals. They can keep their body temperature warmer than the water around them thanks to a specialized blood vessel structure called a counter-current exchanger. This gives them several advantages over cold-blooded fish. Regulating their temperature means tuna can live in various conditions and be found in arctic and tropical waters. The extra heat in their muscles gives them a boost in power and speed. It also helps them dive deep, reaching depths of 500 to 1,000 meters to search for food and to avoid predators.
Albacore tunas, like all tunas, never stop swimming. If you could follow an albacore tuna around the ocean, you would notice something strange: it never stops moving. Like all fish, they need oxygen to fuel their bodies, pulling it from the water through particular organs called gills. Unlike other fish, they lack the structures to pump water over their gills. Instead, albacore tuna swim with their mouths open, allowing water to flow in and wash over their gills. They have adapted to life on the go, with their very long pectoral fins allowing them to save energy by "gliding" through the water.
Tunas travel the oceans in schools that can number in the thousands. They migrate great distances between hunting grounds and spawning grounds. These schools can include hundreds or thousands of fish. For example, albacore tunas travel together in schools up to 19 miles wide!