The common guillemot (known as the common murre in North America) breeds in both the Pacific and the Atlantic and is among the most abundant seabirds in the northern hemisphere. But like many other seabirds, its numbers have declined over the last few decades. Part of that decline is due to the marine environment – a seabird’s home and hunting ground – becoming increasingly unpredictable and difficult to survive in.
Between the summer of 2015 and the spring of 2016, a marine heatwave swept the northern Pacific Ocean that was hotter and lasted longer than any since records began in 1870. Known as “the blob”, the heatwave caused sea surface temperatures along the Pacific coast of North America to rise by 1-2°C. That may sound trivial, but it was enough to cause massive disruption in the marine ecosystem. The fish that common guillemots normally eat, such as herring, sardine and anchovy, either died or moved into cooler waters elsewhere, leaving the guillemots with little to eat. As a result, many birds starved.