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The Silver Ceiling
At first he is more the suggestion of a fish.
A few millimeters of skinless, semi-translucent hatchling, overwhelmed by the eternal blue of the Mediterranean Sea. He is like the uncertain flutter of a distant star, if the stars were moving, always moving.
He has only his own egg yolk to feed on, until his mouth opens for the first time and his eyes begin to develop. Then he can pursue the drifting plankton suspended all around him, and eventually his own siblings if they fail to grow as fast as him. Of course he is a target too, and as his eyes learn to feed him warnings about the danger on all sides, he darts away from every flicker of shadow and colour.
He is only a few days old when he breaks through his first barrier. He rises to the silver ceiling that once defined the world, his tiny tail working hard so his head can break the surface tension. If he is not careful he could become trapped here, too weak to pull himself away and back into the water he knows.
He takes in one gulp of air, and gets his first glimpse of the sky.
His swim bladder inflated and his fins growing firmer, he becomes more buoyant and more busy. He must keep escaping and keep eating. But he also must keep moving to pass water over his gills. Even at night when the water goes dark and his mind goes still, his tail, like his heart, keeps slowly pumping.
As the weeks pass, his body and his place in the world begin to solidify. He can do a little less running and a little more chasing. His siblings cease to be a source of food and become his school. As the summer rolls to an end, there is no way for him to know how unusual it is to be a warm-blooded fish. He only knows that the cooler water doesn't bother him, and he can travel as he pleases. Even thousands of feet down. The Atlantic, as they say, is his oyster.
And so he swims, and he grows. Hundreds of miles turn into thousands, and months turn into years. Surrounded by others like him, he explores coasts and cruises over open ocean trenches. His once delicate form is now defined by streamlined muscles. With power comes speed, helped along by his hydrodynamic design. When the chase is on, he can cut back on resistance by flattening his dorsal fin into a perfect slot on his back. Even at top speeds he can dart in any direction, following his next meal wherever it might lead.
Sometimes, when his belly is full and the water is clear, he likes to rush toward the silver ceiling. He doesn't notice the resistance now; the surface tension has no hold on him. Even though there's no herring or mackerel fleeing before him, he breaks through as he's seen the dolphins do. He leaps and twists then cuts back into the ocean with exactly as much splash as he wants to create. Sometimes he does it to see the sky, sometimes he does it to see the stars, and sometimes he does it simply because he can.
Soon, when he is four years old and over 100 pounds, his instincts will lead him back to the Mediterranean to help create the next generation. If he is able to avoid the hooks and the sharks and the orcas, he could keep going back for another 30 years, when he could be twelve feet long and weigh 1500 pounds.
But for now, he is satisfied to speed across the whole of the Atlantic, a streamlined predator with a desire to touch the sky. He has seen thousands of other fish from every part of this ocean and he can imagine no better life than that of a tuna.
This vignette is about an Atlantic bluefin tuna (scientific name Thunnus thynnus). These are not the type of tuna who end up canned on the shelves of grocery stores (skipjack, albacore, and yellowfin make up most tuna salad sandwiches), but Atlantic, Pacific, and southern bluefin tuna are all eaten as expensive sushi and sashimi. This is a little surprising given that Pacific bluefin are considered a vulnerable species and Atlantic bluefin are categorized as an endangered species on the IUCN Red List. That would be like going into a nice restaurant and ordering a tiger burger. But all species of tuna, like all fish, suffer from being thought of as food first and wildlife second (or not at all). Perhaps if more people could see them break through the surface of the water, they would also break into our collective conscience. That's why I wanted to write about bluefin in a way that focused on the animal, not on the role humans have assigned them. I won't promise full scientific accuracy on this one as I've just started learning about these magnificent animals, but I'm already certain that they are deserving of as much respect and protection as any endangered bird or mammal.
An Atlantic bluefin breaches off Nova Scotia
The one-hour Canada National Film Board (NFB) documentary Bluefin looks at Atlantic bluefin tuna through the lens of one fishing town in Prince Edward Island. Watch Bluefin for free (with ads) on TubiTV.com.
Read a translation of Pablo Neruda's poem "Ode to a Large Tuna in the Market"
Hakai Magazine has two excellent articles about bluefin tuna, "A Tuna's Worth" about the Canadian fishery and "Cracking Open the Tuna Code" about U.S. researchers studying the implications of the bluefin's ability to control their own body temperature.
This Encyclopedia of Life video is ten years old, but it's still an interesting overview of an Atlantic bluefin tracking project that helped scientists better understand the fish's migration
For Netflix subscribers who are particularly tuna-curious, there's a unique double bill available (at least here in Canada; I'm not sure if it's available worldwide). "Cultivating the Seas: History and Future of the Full Cycle Cultured Kindai Tuna" is not so much an actual documentary as it is a promotional film about a Japanese university that has made progress on true farming of Pacific bluefin tuna (previous "farming" efforts involved capturing young tuna from the ocean and fattening them up in cages, which of course did nothing to protect the wild population). But if you prefer you can watch the subtitled Japanese feature film "Tuna Girl" instead, which takes all of the key info from the doc and drops it in around the fictional story of a clumsy and unfocused young woman who signs up to be a student at the fish farm. Either should be watched with a grain of salt, though they do acknowledge the greatest sustainability challenge related to bluefin farming--what to feed the massive fish.
Join the Conversation
What are your feelings on bluefin tuna? Amazing animal, delicious dish, both, or neither? Are there other fish you feel are under-appreciated? Or just let us know what you thought of the issue.
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Thanks for reading,
Marilyn & Steve
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Mouse and Minnow is a free newsletter celebrating animals, sent out most Sundays. It is co-created by partners Steve Alguire (illustration) and Marilyn Anne Campbell (writing). Learn more about the newsletter or use the subscribe button below to receive original art and writing about the wonderful creatures of this world right in your inbox.
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