Like the daffodils and forsythia that brighten up our New England springtime, the North Atlantic sea raven is a garish splash of color in the cold, green waters of the Gulf of Maine – though more unexpected than spring flowers. As David Abel, the Boston Globe reporter lucky enough to go on a recent dive with Brian, describes the surprising sight: “Appearing to be taking a nap on one rock is a bright-yellow sea raven, a monstrous-looking fish about a foot long, with prickly fins, globular eyes, several rows of sharp teeth, and a fleshy mouth ringed with spiny tabs that resemble a poorly groomed beard.”
The sea raven is a member of the sculpin tribe, and, as such, is characterized by a wide mouth, slender body, and large pectoral fins. Sea ravens are not always yellow; their colors range from non-descript browns, to blood red, to the sunburst of color you see in this picture. Robert Glenn, the Chief Marine Fisheries Biologist with the Massachusetts Division of Marine Fisheries, speculates that a sea raven may change colors depending on whether it’s hunting or breeding. According to Glenn, it’s possible that the bright colors emerge in the fall and spring, and are associated with breeding behaviors. But, he says, so little research has been done on this fish that nobody really knows.
While the fish in this picture might look Jimmy Buffet tropical, it has antifreeze in its veins. The sea raven can live at the bottom of Gulf of Maine in temperatures that sometimes approach the freezing point of salt water. Many kinds of sea life make antifreeze, and researchers are looking at the potential commercial application of these compounds, such as better preserving frozen foods, treating hypothermia victims, and making freeze-tolerant crop plants. The chemical composition of the sea ravens’ de-icer is different from every other fish in the sea, and has sparked a great deal of scientific curiosity.
Survival strategies are essential at these icy depths. Formidable rows of teeth and a non-picky appetite allow the sea raven to feed on just about anything it can find, from worms to shellfish to smaller finfish. It doesn’t have to expend a lot of energy hunting, though. The sea raven has a powerful ability to blend in with its background, using coloration and frilly appendages to look like just another algae covered rock. It’s a sit-and-wait predator, and uses its fantastic camouflage to hide in the background until something really big and tasty comes along. Glenn reports that he has found whole Jonah crabs and 16-inch wolffish in sea raven stomachs. This is especially remarkable when you consider that sea ravens only grow to about a foot and a half long, themselves. I would love to be a shrimp on the wall at that dinner party.
Sea ravens are not commercially important (the reason so little research has been done about them), but they are a common bycatch species. Unfortunately, because of their large mouths their stomachs tend to fill with water when they are caught and brought to the surface. Even if they are released alive they cannot deflate rapidly, so they float on the surface where they are vulnerable to predation by seabirds.
Where can you find these fascinating fish? Sea ravens prefer rocky or hard-bottom conditions, like those found in Cashes Ledge, an underwater mountain range 80 miles east of Cape Ann. This special place is one of the biological treasure chests of the Gulf of Maine that CLF is working hard to protect.
Brian has plans to dive on Cashes Ledge several times over the next few years, and we are very excited to show you what other unexpected gems he finds. Stay tuned!