It was not long ago that we blogged that one in eight bird species could be in trouble over climate change.

The numbers of the iconic puffin have fallen by nearly a third in a key colony off Scotland in the North Sea. Researchers fear this could indicate a national trend caused by warming seas brought on by climate change.

Researchers on the Isle of May, home to the largest puffin colony in the North Sea, have found that after 40 years of steady increase the resident population has plummeted by almost a third in the past five years.

The Scottish island has been at the centre of the UK’s research into puffins for more than three decades, and findings are often seen as an indication of the state of the birds nationally.

Mike Harris, emeritus professor for the Centre for Ecology and Hydrology, who conducted the research, said the news was alarming. “This is a warning”, he said. “We’ve been working on puffins on the island since 1972, and this is the first time I’ve been concerned that something has gone wrong in their environment”.

“We think there’s been some change in their native environment in the last couple of years. One possibility is that there’s been a big change in the sea, from intense fishing and marine climate change. This has affected the development of plankton, which in turn has an impact on the numbers of fish for the puffins to eat.”