Researchers are keeping a close eye on puffin populations on the east coast this summer after a couple of rough years for the seabirds.

In Maine, Atlantic puffins have been dying of starvation and breeding rates have been low.

Researchers won't know the extent of damage to the puffin population until the end of the year. (Bobbi-Jean MacKinnon/CBC) The situation in New Brunswick hasn't been much better, said Tony Diamond, a research professor at the University of New Brunswick and director of the Atlantic Lab for Avian Research.

Machias Seal Island, which is on the Maine-Canada border and home to about 10,000 puffins, reported a terrible breeding season last year after many of the adult birds were killed off by the winter, he said.

Diamond, who has a team spending the summer on Machias, located about 18 kilometres southwest of Grand Manan on the Bay of Fundy, is cautiously optimistic conditions are improving.

"Slightly over two-thirds of the burrows that we have marked and monitor regularly every year, about two-thirds of those already have eggs in, whereas at this time last year, it was about a quarter of them or less," he said.

"The only indication we have at this stage of the season about how things are going to be is the weight of the adults, which seems more or less normal and the timing of breeding and the proportion of burrows that are occupied."

Researchers won't know the full extent of the damage to the puffin population until the end of the year, said Diamond.

"We will know how it affected adult survival at the end of this year because we measure survival by watching systematically birds that are visible and recording their band numbers. And that, with fairly complicated statistical programs, can tell you what their survival is. But you don't know what it is in a given year until a year after that," he said.

Diamond says changes to the oceanic system are likely to blame for last year's difficult season. Fish populations have been shifting as ocean temperatures rise.

Machias Seal Island is a designated migratory bird sanctuary, maintained by the Canadian Wildlife Service.