Among the declines the researchers are noticing: historically hardy populations of gulls and murres are only half what they were 10 years ago, and only a few chicks hatched this spring. Mussel shells are notably thinner, and recently the mussels seem to be detaching from rocks more easily and with greater frequency.

Goose barnacles are also suffering, and so are the hard, splotchy, wine-colored coralline algae, which appear like graffiti along rocky shorelines.

While not entirely understood, the declines are not entirely mysterious. Biologists suspect that the shifts are related to huge declines in the water’s pH, a shift attributed to the absorption of excess carbon dioxide being released into the atmosphere in ever-greater amounts by the burning of fossil fuels for energy.