Our oceans have been getting steadily warmer for over a century, and they are expected to continue getting warmer-both in the top layer and in deeper waters. While there is some debate over the various causes and mankind's contribution to this trend, the data is clear; even if people stop adding extra greenhouse gases to the atmosphere now, oceans will continue to get warmer for many years as they slowly absorb extra heat from the atmosphere.

If you have been following this newsletter, you are well aware of some of the ways some scientists think that climate change and ocean warming are effecting marine life, from the bleaching of coral reefs, to increasing frequency of large algae blooms in what used to be cool clear coastal waters. But it's not just our reefs and swimming holes that are impacted by climate change.

This Atlantic puffin (Fratercula arctica) has a mouthful of herring fry - now a rare sight in today's warmer marine environment. Photo:  Thomas Aarvak

For instance, some research suggests that herring, alewife and other groundfish are now  migrating further north into Canada to escape the warmth of the Gulf of Maine in search of cooler water for spawning and feeding.  This change may be impacting sea birds like Atlantic puffins, which are struggling, with only 31% survival rate of fledgelings on Maine's two largest colonies, dozens of emaciated birds found washed ashore in Massachusetts and Bermuda, and declining health and lower body weight in previously thriving colonies this past winter. These charismatic "clowns of the sea" or "penguins of the north" count on the formerly ubiquitous schools of tiny herring to feed their fledgelings.  Researchers have discovered that, with herring populations reduced in many areas last season, puffins may be turning toward butterfish as a food source for their young.  However, the baby birds' throats are too small to swallow these bigger, rounder fish, and many puffins have ended up choking to death or dying of starvation.