By Susan Hand Shetterly
A few years ago, I walked into the lobby of the Science Building at University of Maine at Machias and found, suspended within a glass box by almost invisible airplane wires, the skeleton of a bluefin tuna. Those bones, the bare architectural structure of a superb animal, touched me the same way the medieval profile of the peregrine falcon does, or the tom turkey’s fanned tail in spring, or the dappled coat of a whitetail fawn.
Perhaps we humans are programmed to respond to successful evolutionary adaptations as we might to the light and shadow of a Rembrandt canvas or to the curves of a Michelangelo sculpture. Perhaps animals gave us our first lesson in aesthetics, and that’s why we scrawled their images onto cave walls. Yes, many of them were good to eat, and we hunted them in small, armed packs, but we also may have loved to watch the way they moved through their lives.
Gayle Kraus is a professor of marine biology at Machias. She and her students assembled that bluefin skeleton in a course she calls Skeletal Articulation. But the work began on a hot afternoon one August, when she found herself in a salt marsh in the town of Milbridge, elbows deep in the rotting bluefin carcass. She retrieved as many bones as she could find from the maggot-rich flesh, packed them up, and carried them back to her lab, where she cleaned them. Then, along with seven students, she set about figuring out how the bones might have fit together in life, when this fish came barreling into the marsh on a spring tide, chasing mackerel. “We used hot glue because we were just learning,” she tells me, “and if we put some bones together incorrectly, we could simply use a hair dryer, melt the glue, take the bones apart, and try again.” They spent a full semester with this jigsaw skeleton. “It was terribly exciting,” she says.
Perhaps animals gave us our first lesson in aesthetics, and that’s why we scrawled their images onto cave walls.
The skeleton turned out to be almost 8 feet long, which means the fish must have weighed more than 500 pounds. Bluefins swim by holding their bodies rigid and whipping their tails back and forth. Those caudal fins, shaped like a crescent moon, drive the fish forward in bursts of speed up to 40 miles an hour as they travel in big schools, hunting herring, eels, squid, and mackerel. They can leap fully out of the water, suspended in the air — like the skeleton — for an instant before they drop back down, and they deep-dive to 2,000 feet because they are warm-blooded, adjusting easily to cold. Our western Atlantic schools spawn in the Gulf of Mexico, come north into the Gulf of Maine and up to the Gulf of St.Lawrence, and swim back and forth across the ocean from here to the coasts of Spain and Portugal.
Since 2012, marine biologists have been working to bolster the diminished and endangered population of western Atlantic bluefins. It’s a difficult science. They must figure out how to protect spawning areas, track the movements of adults, monitor the lives of the juveniles, and set international and enforceable policies.
All this, and then along comes climate change, with its impacts on ocean temps and the distribution of prey, to make these studies even more difficult and important.
Over months, as Gayle’s students learned about the lives of bluefins, they picked up bones, large and small, dipped them in glue, and fitted them into the places where they thought they belonged — along the spine, around the head, in the fins — and crafted something beautiful: a testament to a wild life.