It’s approximately two o’clock in the morning, mid-April, 2007, and our crew of three is searching for the elusive Marbled Murrelet. We are in a 16 foot zodiac, near Mink Island, and trying our best to stay warm. The Marbled Murrelet is a small, threatened seabird that spends the majority of its life at sea, but nests high on mossy limbs of coastal old growth trees. They are referred to as MAMU, foglarks, Brachyramphus marmoratus, and even “kiss-me- asses”. The only reliable method of catching these birds involves using a spotlight and a long salmon landing net to dip net the birds from a zodiac at night. The work is difficult and requires exorbitant amounts of patience, as we only capture one bird for every three hours spent searching. Desolation Sound provides an ideal site to capture murrelets due to its sheltered location and high murrelet densities. For this reason, murrelet research has been based out of Lund since the mid-90’s and will continue again this summer. Unfortunately these birds are becoming more difficult to find due to widespread declines in abundance throughout their range, from California to Alaska. The most recent conservation assessment from U.S. government biologists estimates that populations have declined by 70% over the past 20 years in British Columbia and Alaska.

Logging of coastal forests has reduced the availability of nesting habitat for these birds and is considered the primary mechanism responsible for the population crashes. However, a growing body of scientific evidence suggests that changes in ocean climate may also be partly to blame. Large scale variation in ocean temperature can alter the structure and function of marine food webs and have negative consequences for marine predators, including salmon, whales, and seabirds.
Our research is a collaboration between biologists at the University of Guelph, the University of British Columbia, and the Canadian Wildlife Service. Our goal is to try and understand whether changes in ocean climate may influence the availability of prey fish and in turn, the breeding success of Marbled Murrelets. When we capture a bird we pluck a breast feather and take a small blood sample. We then use stable isotopes of carbon and nitrogen from the feather and blood samples as chemical signatures that we compare to isotope signatures from different species of forage fish. This allows us to determine what species of fish are important to murrelets during breeding. Using feathers of murrelet specimens from museum collections, we are then able to reconstruct historic diet over the past 150 years. This allows us to look for relationships between diet, prey availability and ocean climate. By understanding how changes in ocean climate influence abundance of forage fish and diet, we hope to provide information necessary for the conserv