North Atlantic Thick-Billed Murre International Harvest Management Strategy

Thick-Billed Murres in the Northwest Atlantic

Thick billed murres (Brünnich’s guillemot, Appa, Polarlomvi, Stuttnefja, ᐊᒃᐸ, Uria lomvia) can live for as much as 40 years. At most, they produce one chick per year.

Chicks leave their nesting ledge on the cliff when less than half grown and jump into the ocean. There they meet with their fathers who feed and care for them. The fathers cannot fly at this stage because they are moulting. The fathers and chicks swim long distances, sometimes more than 1000 kilometres to reaching wintering grounds that do not ice over.

This map shows breeding colonies, migration routes and main wintering areas in the northwest Atlantic. Black dots show the colonies, and the lines and arrows show the routes they take in the fall. The green shows the wintering area mostly used by birds from colonies in Canada and northwest Greenland. The two orange areas are mostly used by birds from Svalbard and Iceland, and the blue area is mostly used by birds from southwest Greenland. Because of the mixing of birds from different breeding colonies in their winter range, both environmental conditions and human activities in winter affect breeding colonies in several countries.

Thick-billed murre breeding colonies in Svalbard, Iceland and most of Greenland have declined in size over the past ten years, whereas colonies in northwest Greenland are increasing. In Canada, the status of the murre colonies is not well known, but the Canadian government is working on establishing the current status of the Canadian population.

International management of Thick-billed murre is needed due to the species highly migratory nature, which results in birds from different breeding regions and countries, with differing population trends, mixing on the wintering grounds.

The most important cause of decline is likely a lack of food in winter. Researchers have tracked birds with electronic tags. Murres wintering in areas around Greenland have to work harder for food in winter than those wintering along the Canadian coast. The assumption is that this change in food availability may be linked to climate change.

Harvest also inevitably reduces populations, but cannot on its own explain the observed declines.

Other potential causes include:

• Extreme weather – murres may be stressed by e.g. increasingly hot Arctic summers
• Disturbance – increased human activity near colonies, including harvest and tourism may also add to stress, accidents to chicks, and other impacts
• Bycatch – this was once significant, but major reductions in gillnet fishing along with some improvements in fishing methods mean this is likely not as important a driver recently
• Contaminants – not thought to be an important driver.

Harvest levels seem to have declined over the past few years. Estimates for current annual harvest levels are:

• Canada (primarily Newfoundland and Labrador) – 40,000 - 95,000
• Greenland – 25,000
• Iceland – less than 5,000

Changing harvest regulations could be one response to the declining populations. Because breeding populations mix in winter, harvest levels should ideally be managed according to an internationally agreed management plan.