Large-scale seabird movements throughout the year - SEATRACK 2014-2018


Research notes:

The large-scale seabird tracking programme SEATRACK has finished its first five-year phase. The project has improved and expanded what we know of the behaviour and distribution of Northeast Atlantic seabirds. One key finding is that the Barents Sea is far more important in winter than previously known.

Seabirds migrate and gather in colonies with no regard to national borders or jurisdictions. Consequently, the responsibility for the conservation and management of seabirds is shared among several nations. An estimated 26 million pairs of seabirds breed in colonies along the coast of the Northeast Atlantic and the European Arctic, and many species are in severe long-term population declines. Photo: Håvard Eggen.

Halfdan H Helgason, Hallvard Strøm, Sébastien Descamps and Benjamin Merkel // Norwegian Polar Institute. Børge Moe, Vegard Bråthen, Arnaud Tarroux and Per Fauchald // Norwegian Institute for Nature Research. Morten Ekker // Norwegian Environment Agency

1.

SEATRACK was formally initiated in spring 2014. The aim of the project was to map where seabirds that breed in colonies encircling the Barents, Norwegian and North Seas are during the non-breeding season. This would allow us to predict how changes in environmental conditions in wintering areas might affect seabird demography and population trends. As long as we were unable to determine the movements of individuals from different breeding populations, our understanding of seabird distribution and the potential causes and consequences of different migration strategies was severely limited.

The advent of global location sensing technology, at last, gave us the tools we needed to link breeding populations to their non-breeding habitats, a knowledge that is essential for marine spatial planning and seabird conservation. SEATRACK has also given us a range of invaluable tools for population management and seabird research.

Seabirds migrate and gather in colonies with no regard to national borders or jurisdictions. Consequently, the responsibility for the conservation and management of seabirds is shared among several nations.

An estimated 26 million pairs of seabirds breed in colonies along the coast of the Northeast Atlantic and the European Arctic, and many species are in severe long-term population declines. In order to predict potential threats and assess a species’ resilience, we need a good understanding of wintering and staging areas and how the birds use them, which migratory routes they follow, and how populations spread and mix.

This was the thinking behind SEATRACK, a coordinated multi-year, multi-site and multi-species seabird tracking effort. The project spanned 38 colonies in five countries. Individuals of 11 seabird species were tagged with small, lightweight archival tags, called geolocators. Each individual’s position can be calculated twice daily using the ambient light levels recorded by the tag, in relation to the time of day. Since the tags are archival, they must be physically recovered to obtain data, and recapturing each tagged individual is an interesting challenge. However, the novelty of the project lies not in the technology used, but on the large scale and synchronicity of the deployment efforts, and the standardised methodology.

2.

Over the last five years, more than 10 500 geolocators have been deployed and so far over 4 400 have been retrieved, shedding light on individuals’ locations throughout the year. In early 2018, the project database held around 1.6 million raw positions comprising 3 363 annual tracks from 2 130 individuals. Data gleaned from 1 214 loggers retrieved in 2018 have yet to be processed into the database and will likely yield about 2 000 additional tracks. All data currently available in SEATRACK’s database can be viewed online in a web application http://seatrack.seapop.no/map/ which was launched in March 2017 along with the project’s webpage http://www.seapop.no/en/seatrack. In this freely accessible web application, users can plot and compare the distribution kernels of various species and/or populations in different seasons and years. SEATRACK data can also be combined with environmental data and population sizes and used to predict an abundance of seabirds in time and space.

For example, new map products are being developed to show habitat and abundance. The first version of the abundance maps for six of the study species was introduced in October 2018. These maps constitute a new and extremely useful tool for population management and marine spatial planning and will likely prove invaluable both in conservation efforts and in responses to acute threats such as oil spills. The SEATRACK web application will soon also include abundance maps.

Seabird colonies where loggers have been deployed on behalf of SEATRACK 2014-2018.
Predicted absolute densities (abundance) of Atlantic puffins breeding in colonies around the northeast Atlantic in January. The model is based on a range of environmental variables, population sizes and SEATRACK data, extrapolated to cover over 90% of the northeast Atlantic population.

3.

To date, SEATRACK has provided unique insight into details in the life history of different seabird populations, such as timing of migration, migration routes and selection of overwintering areas. New information has come to light while more detailed analyses of the data are still under way. It has become clear that certain geographical areas are crucial to seabird species throughout the winter or for shorter periods in autumn. One of the most important findings so far is that the Barents Sea is much more important as a wintering ground – and important for more seabird populations – than previously thought. It turns out that huge numbers of seabirds spend the winter in the Barents Sea, for example, the large Brünnich’s guillemot populations from the east coast of Spitsbergen and Novaya Zemlya – populations that have never been tracked before.

 

To date, SEATRACK has provided unique insight into details in the life history of different seabird populations, such as the timing of migration, migration routes and selection of overwintering areas. New information has come to light while more detailed analyses of the data are still underway. It has become clear that certain geographical areas are crucial to seabird species throughout the winter or for shorter periods in autumn. One of the most important findings so far is that the Barents Sea is much more important as a wintering ground – and important for more seabird populations – than previously thought. It turns out that huge numbers of seabirds spend the winter in the Barents Sea, for example, the large Brünnich’s guillemot populations from the east coast of Spitsbergen and Novaya Zemlya – populations that have never been tracked before.

 

Much work remains, but at the end of 2018, the project had run its course as originally scheduled. To complete that work, address new questions that have arisen, and establish new technological know-how, we have drawn up plans for a second phase of the project and funding is being sought. The first phase was financed jointly by the Ministry of Climate and Environment, the Ministry of Foreign Affairs and the Norwegian Oil and Gas Association, along with nine corporations in the energy sector (Equinor, Neptune Energy, DEA Norway, Eni Norway, ConocoPhillips, Total, Wintershall, Aker BP and Lundin).

The programme is led by the Norwegian Polar Institute in collaboration with the Norwegian Institute for Nature Research and the Norwegian Environment Agency. SEATRACK involves close cooperation with specialists in each partner country, with more than 20 participating institutions contributing to the effort.

 

Authors

Halfdan H Helgason, Hallvard Strøm, Sébastien Descamps and Benjamin Merkel // Norwegian Polar Institute

Børge Moe, Vegard Bråthen, Arnaud Tarroux and Per Fauchald // Norwegian Institute for Nature Research

Morten Ekker // Norwegian Environment Agency