Seabirds 2021

In 2017, the SAMBR synthesized data about biodiversity in Arctic marine ecosystems around the circumpolar Arctic. SAMBR highlighted observed changes and relevant monitoring gaps using data compiled through 2015. In 2021 an update was provided on the status of seabirds in circumpolar Arctic using data from 2016–2019. Most changes reflect access to improved population estimates, orimproved data for monitoring trends,independent of recognized trends in population size. Access 2017 report here

• Seabirds continue to be impacted by climate-driven shifts in their food supplies and by the retreat of sea ice.

• From 2016–2019, broad declines in Atlantic Arctic seabirds continued, with new population declines in some previously healthy populations of common eiders. In other cases, some of the previously declining small populations of ivory gulls have stabilized, although larger populations have declined in Kara-Laptev. Large data gaps still prevent a clear assessment of trends in planktivorous seabirds, and most seabirds in the Russian Arctic.

• For monitoring and the planning of conservation measures, international collaboration is essential. For example, an Arctic Report Card was produced and an international pan-Arctic ivory gull survey is being conducted within CBird. For the black-legged kittiwake, an international conservation strategy and action plan has been developed

What is happening and why does it matter?

• This 2021 assessment continues to show instances of stable or increasing population trends in the Beaufort, Pacific Arctic, Arctic Archipelago, and Davis-Baffin areas, although there are additional unknown trends in those regions. For most of these regions, monitoring is sporadic or sparse.

• As reported in 2017 there were more declining population trends in the Atlantic Arctic, particularly for kittiwakes and both species of murres.

• Ivory gull trends improved in two small populations (Canada and Greenland), but declined in others. Thus, within the Arctic Archipelago and Atlantic Arctic, population trends are different, and the trend is negative in the Kara-Laptev region, which holds the largest population.

• Common eiders, although generally doing well throughout all regions, changed from increasing to decreasing in two regions of the Atlantic Arctic.

• The declines observed are consistent with wider changes in the marine ecosystem in the North Atlantic, suggesting that seabirds have been impacted by large scale environmental change. Another factor in more specific locations is fisheries bycatch, which might pose a risk for populations of diving seabirds, although a full assessment of the population consequences is challenging.

• It must be noted that the regions extend over large areas and are not ecologically uniform. As a result, seabird population trends may not be consistent within a region, leading to a ‘split’ in trends. This applies to such large regions as the Atlantic and Pacific Arctic AMAs. For instance, in the Barents area (Atlantic Arctic) there is a decline of thick-billed murres and black-legged kittiwakes in areas influenced by Atlantic waters, whereas in the north-east, populations are stable or have increased in the short-term.

• In some areas, such as the Atlantic Arctic, FEC species, e.g. Black-legged kittiwakes, common and thick-billed murre populations are decreasing while in other areas such as the Pacific-Arctic, species are increasing. 

Why are seabirds important?

• Seabirds link marine, coastal and terrestrial ecosystems inside and outside the Arctic because they nest on land but forage and moult at sea, and, thus, they are important components of Arctic ecosystems

• Seabirds provide valuable ecosystem services to humans, notably for food, clothing, tourism and as nutrient recyclers where they help break down organic and inorganic materials to replenish minerals and nutrients in the ecosystem.

What should you know about the monitoring data?

• Seabird population trends are relatively well known, although not for all species

• Some of the most widely monitored species groups in circumpolar regions include common and thick-billed murres (diving piscivores), black-legged kittiwakes (surface piscivores), and common eider (benthivores); these species groups make it possible to conduct comparative studies across circumpolar regions.

What are the most important drivers? 

• Important drivers for seabird population changes include climate change, reduced sea-ice, changes in sea temperatures, changes in food webs and species interactions, disease outbreaks, hunting, fisheries bycatch, and pollution (contaminants and oil pollution).

Where is monitoring happening?

• Most circumpolar nations have at least one source of long-term seabird monitoring datasets, but efforts vary across regions. Colony-based monitoring occurs regularly or annually, although most sites do not have fully implemented plans, with diet and survival data often lacking. At-sea surveys are more opportunistic, and often occur in conjunction with resource exploration and extraction.

• Generally, the Atlantic Arctic is more intensively monitored than the Pacific, due to greater accessibility of colony sites and resources for monitoring, as well as gathering and documenting information.

• As in 2017 data gaps are most apparent for population information on the least auklet and little auk, and geographically for the Russian Pacific Arctic and Kara-Laptev regions.

• During 2020 the COVID-19 pandemic restricted monitoring e.g. in Canada and the US. The financial aftermath of the pandemic and its implications for future monitoring funding remain a concern.

Advice for monitoring 2017: seabirds

• Develop methods for assessing diet to increase our understanding of changes in the ecosystem and how they affect seabird populations.

• When selecting sites for new monitoring, consider proximity to hotspots for marine activities, access to the sea, and inclusion of plankton monitoring.

• Expand colony-based monitoring and strive to include a more complete array of parameters, in particular, diet and measures of survival.

• Consider a higher frequency of monitoring as current levels make it difficult to identify mechanisms or causes of change in populations.

• Conduct targeted surveys and individual tracking studies of seabird interactions at sea to improve our understanding of seabird interactions at sea, where seabirds spend most of their time.

• Continue to conduct at sea surveys on an opportunistic basis.