Wildlife at the Surface
Although our primary purpose out here is studying what lives in the deepwater canyons, we can’t help noticing the life on the surface of the sea. It is not unusual to spot whale blows in the distance, or to have a call from the bridge “dolphins on the starboard fantail” which draws us all out of the lab.
Birds are common. It is not unusual for us to see gulls circling (and occasionally landing on) the ship. Terns are frequent visitors too. During the Jason recovery a common tern, Sterna hirundo, first settled on the A-frame (that holds the Medea) and then on the LARS (that holds the Jason). This bird breeds from Canada to the Carolinas, as well as southern Scandinavia, and winters in the Caribbean, southern Florida and northern Africa. As its name suggests, it is quite common!
Another frequent sighting is the Wilson’s storm petrel. This small black bird has a distinctive white patch on its rump, and appears to “walk on water” as it dabbles its webbed feet on the surface. It nests in Antarctica but spends the rest of its life at sea. One got trapped in some water on the deck of the ship. After extracting it, and letting it get warm and dry, we released it, and it flew off over the waves.
During the recovery of Jason an osprey, Pandion haliaetus, flew by. This was unusual because ospreys tend to stay within 10 km of their roosting site. We wondered if perhaps the bird we saw was migratory. Ospreys breed on every continent except Antarctica so perhaps this one was returning north after spending the winter in South America. Ospreys are skilled hunters with an outer toe that is reversible, which allows them to carry fish with two toes on each side. Their species name, haliaetus, comes from the Greek “halos” which means sea, and “aetus” which means eagle; a fitting name for a bird with hunting abilities that were so amazing there was a Medieval belief that the osprey mesmerized the fish, making them turn belly up.
We have had several calls for seeing a “fin” in the water. On two occasions it was a Mola mola or ocean sunfish. These unusually shaped fish appear to be “all head” and are as tall as they are long. They have a long dorsal fin on the top and long anal fin on the bottom, and not much of a body. This unusual shape has led to a variety of names. Mola means millstone in Latin, in reference to its round shape. Most European names mean “moonfish” in reference to the shape, however its English name, “sunfish,” comes from its habit of sunbathing at the surface. It propels itself through the water by a sculling motion with its fins. It is the heaviest bony fish known — an average adult can weigh 2,200 pounds. Females produce more eggs (300 million!) than any other known vertebrate. The young fish (called fry) are spiky and resemble miniature pufferfish. They eat jellyfish, squid, salps, and crustaceans found throughout the water column. The Museum has a replica of one on display on the second floor of the Main Building if you want to check one out!
We have also seen other fins in the water, including dolphins. We saw common dolphins playing in the waves and they put on quite a show. We have seen fins that we are certain belong to whales. Early in the cruise we spotted a minke whale. We could see the blow, a fin, and a bit of its back as it dove. During our weekly safety drill we spotted a blow and a fluke in the distance as we stood outside with our lifejackets on. We decided that had to be a humpback. We have spotted other blows in the distance (last night there were 8 distinct blows in a 2 minute span!) but have not been able to see a fin. Two pairs of shark fins were spotted one afternoon, and we could catches glimpses of the fins between the swells. We could not decide what type of shark they were and could not even agree on how big they were! Our length estimates ranged from the conservative of 8 feet to the high end of 20 feet.
The majority of our day is spent indoors, working in the science labs or the ROV Control Van, but when we get outside we look for the wildlife of the surface.