Scientists are researching the possible causes of mass die offs of sea birds along the Pacific Coast, but remain puzzled.

Deaths of sea birds have been on the rise since October 2014, with the most affected species named as the Cassin’s aucklet, a small gray species with a white stomach area. Locals first noticed the mass die offs in British Columbia, but reports have come in from as far south as San Luis Obispo, California.

Scientists Puzzled By Mass Deaths Of Sea Birds On Pacific Coast

Scientists put to work

Researchers from the University of Washington’s Coastal Observation have been working in conjunction with the Seabird Survey Team, counting over 1,200 dead birds since the last quarter of 2014.

According to researchers, sea bird deaths are common during the cold winter months, but the alarm has been raised by the large number of deaths, which Philip Johnson, executive director of the Oregon Shores Conservation Coalition, claimed was “kind of unprecedented. It’s an interesting and somewhat mysterious event.”

Scientists postulated that pollution could be responsible for the deaths, but have since discovered that most are dying of starvation. The next piece of the puzzle is to work out why the birds are unable to hunt for food.

Possible explanations for the deaths of sea birds

Some researchers have claimed that one possible explanation stems from a prolific breeding season for the sea birds. The huge number of new hatchlings would increase competition for food, and lead to the deaths of weaker members of the species.

Other explanations include strong storms which force the birds into unfamiliar areas or prevent them searching for food, as well as a decrease in the zooplankton population because of a warmer, more acidic ocean. Zooplankton are an important source of food for the sea birds, and increased competition coupled with decreased food supply could explain the dramatic number of deaths.

Researchers are receiving assistance from the U.S. Geological Survey’s National Wildlife Health Center in Wisconsin, which is carrying out necropsies on the dead birds.