Cooler water, better birding. That's the message I've been getting from Debi Shearwater as she reports via email on her pelagic birding trips along the central California coast. I'll be out there later this month for two trips, one out of Monterey, the other from Half Moon Bay, north of Monterey. Debi has written with excitement about encounters with flocks of seabirds when the boat carrying her and her clients finds cooler water, water at or very near 60F degrees.
A little Internet research found a report about birding along the Mendocino Ridge, which is north of San Francisco. South of the ridge, which extends 2,500 miles offshore from Cape Mendocino, water depth plunges 5,000 to 10,000 feet. Cooler water from those depths can be pushed to the surface when driven against the face of the scarp. Cooler water, as I understand it, is appropriate habitat for animals, particularly krill, that are eaten by certain seabirds and whales. A report on scientific work done along the ridge said temperature drops of three to four degrees were found, the lowest temp at about 60 degrees. The appearance of cooler water can occur at other points along the California shore, depending on topography of the sea bottom and wind and currents. It is this 60-degree water that Shearwater seeks. Whales alone would make her trips exciting. One day last week she reported seeing 11 Blue Whales plus 20 Humpback whales, the latter feeding together, occasionally breaching near the boat.
My question is what happens to the krill and other creatures eaten by birds and whales if, because of risings sea temps, the preferred colder water cannot be found? What happens to the krill and the birds and whales? Pelagic birding along the California coast would change, I assume, and not for the better. I'm glad I can go out on those boats now.
Birding on the Shearwater trips is the most exciting, the best birding I've ever done. The photo of the Black-footed Albatross was taken on a pelagic trip out of Monterey.