Ringed seals and ICE
In the ICE Ecosystems’ ringed seal project we will take a closer look at the distribution and movement patterns of ringed seals in Svalbard. Read our "newsletter" from the researchers in the field this summer.
Ringed seals are a circumpolar species that is totally dependent on sea ice for all aspects of its life cycle. Ringed seals give birth on ice, mate in association with it, moult and rest on it, and receive considerable protection from it against predators – particularly killer whales. Ringed seals also eat a lot of ice-associated prey, including young polar cod and large ice amphipods in Svalbard.
Ringed seals are the most common seal species found in the Arctic and the world population numbers in the millions. Changes in the extent and type(s) of sea ice will certainly have negative impacts on the distribution and survivorship of ringed seals, which will in turn have large impacts both up and down the arctic food-chain. For example, ringed seals are the single most important prey species for polar bears. In several areas across the distribution of ringed seals a decline in reproduction has been documented with declining sea ice extent, seasonal duration and quality. Within the ICE Ringed seal project we will undertake detailed analyses of habitat choice, foraging areas, activity budgets and movement patterns as well as exploring ringed seal diet via fatty-acid analyses and stable isotopes with tissue samples collected from our captured seals. These investigations will improve our predictive capacity with regard to how climate change will impact this important arctic seal. Unique new satellite tags will be used in this project that provide all of the “standard” information about diving and locations, but in addition measure and transmit oceanographic data (salinity and temperature with a high level of precision) and measure primary production (via a fluorescence meter) in the areas where the seals swim and dive.
The goal of this first year of field work within the project is to capture 10 ringed seals and instrument them with these new high-tech satellite tags and collect blood and a small sample of fat for diet analyses. Much of the activity within the ICE Ecosystem project will take place in the area around Rijpfjorden in the north of Nordaustlandet in Svalbard, so we hope to capture and instrument our ringed seals in this area.
Our field work is taking place using a sailboat as a home-base. We have two zodiacs towed along behind us that serve as net-setting/capture boats; these small boats also allow us to check coastlines and potential anchorages more quickly too. Using our little flotilla of boats gives a degree of flexibility, allowing us to move around following weather, wind and ice conditions that we encounter, shifting to areas where we can work when conditions close us down in a particular area for too long. Our departure for the field took place on the 15th of July from Longyearbyen. After 4 long days of sailing in some pretty tough winds we arrived up in Beverlysundet, a bit west of Rijpfjorden. Here we were stopped by ice and held weather fast for a day (20th of July) with gale force winds from the north and heavy snow.
Yesterday we set capture nets from a small island called Søre Castrénøya, but we did not manage to attract any seals. In fact, we did not even see a seal the whole day (despite having seen several in the area very late the previous evening). But, what we have seen a lot of are polar bears.
We had 9 bears on the northwest corner of Spitsbergen when we sailed past some days ago and we had 13 out on the ice east of Søre Castrénøya. It looks as though it is a dead whale frozen-fast into the ice that is the big attraction at this latter location. In addition to these bears that we seen at good distances, we also had two bears visit at Castrénøya while we were guarding the seal nets. One visit was a little too intimate for comfort and could have easily ended badly. While we were watching the nets a young male bear suddenly appeared blasting toward us at full speed. We had not seen him at all prior to a distance of about 25 m, when he was already in full attack-mode. With considerable speed rifles were raised and other protective gear put in place (Hans pulled a long log out of the bonfire). All the disturbance in the group and 4 growling/bellowing people caused the bear to slow his speed and shift his attention among the members of the group such that a warning shot could be fired over the bear (rather than into him), which caused him to stop the charge and reconsider things. With more hollering and several boom-gun shots he turned and retreated. We measured the distance from us to his stopping position. It was 9 m. After several hours he came back and laid down about 100 m from us. Despite his sweet, and this time – innocent – looks he was not at all welcome in our zone. So boom-guns were again deployed to ensure that he knew he was not wanted in the area. He departed quickly this time and did not return again.
We are currently laying weather-fast here in Dalvågen in Beverlysund and it is a bit hard to think that it is the 20th of July and peak summer. It has snowed throughout the day and the wind has remained strong. But, the weather report has arrived on our iridium email link (thanks logistics folks!) and it looks promising. We hope to sail to the east side of Rijpfjorden as soon as the wind drops a bit, which would be an ideal area to capture our seals. Today’s ice map will come in a few hours and confirm whether we will be able to get where we hope to head next. So – no seals so far, but we have just gotten into the “zone” and have every expectation that things will pick up soon.