Sunrise on the Continental Shelf
This past weekend was spent at sea with friends on a pelagic (off shore) trip out of Cape Cod, Massachusetts. We left at 1:00 a.m. and traveled out about 100 miles to Hydrographer’s Canyon which is on the edge of the Continental Shelf. This canyon (named for the research vessel that first explored it) cuts 11 miles into the edge of the shelf and is 3.5 miles wide at its mouth. The Canyon is a hotspot of biodiversity, something I experienced first hand. When we approached the edge of the shelf the sea temperature was about 54º. At the Canyon, the color of the water changed dramatically, the sea temperature rose to about 72º and I peeled off layers as the air warmed to a very comfortable temperature. The theory is that this temperature change is caused by what are called Gulf Stream Rings which break off from the Gulf Stream and are channeled into the area when the Gulf Stream passes over a line of sunken extinct volcanoes called the New England Seamount Chain. [For a better explanation of all this, check the link I provided above.]
So what did we see? Five species of Shearwaters, four species of Storm Petrels, Long-tailed Jaegers, Fin Whales, two species of dolphins and pods of porpoises. I got four life birds, according to eBird! The bird species changed from cold water specialists (like the Sooty Shearwater) to warm water or tropical specialists (like Audubon’s Shearwater) as we entered the canyon.
These Wilson’s Storm Petrels pattering over the water reminded me of puddling butterflies with their delicate movements.
