Fieldwork on seals and whales, summer 2016
Like many summers in the past, we have had a research expedition in Svalbard's coastal waters, using the sailboat Meridian as a base to work with various seals and whales. This year our primary target was white whales, but the ringed seal was also a focal species. Sampling has been done on the large whales sighted along our path as well.
We operated in a restricted area on the west side of Spitsbergen during the whole expedition this year, with most of our time spent searching for white whales.
This tagging/sampling operation is part of our Norwegian Research Council funded project
Ice whales, in which all of the cetacean community in Svalbard is featured, with the three Arctic resident species receiving special focus.
When we find white whales, we shoot out ahead of them and set a net from land, and then attempt to guide one of them into the net. Even though this is a small whale species, they often weigh over 1000 kg, so one is enough for the net – and us – to deal with at a time.
When we have a strike, we work quickly to get the whale disentangled and secured, using a tail rope over the fluke to limit mobility and a head net to ensure that we have control over the whale's breathing.
We then set about taking the measurements and samples (blood, skin scrapes, blow expulsions, skin and blubber) and finally – we get the satellite tag attached.
Our measurements of length and girth (around the animal at the level of the front flippers) are used to estimate weight. The various samples collected will be used for dietary, ecotoxicology, health and genetics studies. The blow expulsions are new for us – these will be used for metabolonics studies (molecular level health testing).
The satellite tag is mounted on the dorsal ridge. These tags report the locations of the animals and their dive depths and durations as well as water temperature.
When the tag is secure, the whale is carefully guided off the beach, such that it cannot roll on its new
jewellery. Then it is time to repair the net for the next capture event.
Once we have an animal in a pod marked, we can use its locations to find the group again to attempt to capture additional animals. Several of the animals we captured this summer were found in this way.
This summer we also captured and instrumented ringed seals with GPS satellite tags that perform CTD measurements. These tags report their detailed geographic and oceanographic data directly to the Argos satellite system.
We hope that the animals will spend a lot of their time near tidal glacier fronts to provide detailed data on the dynamics of these important water masses, which are difficult to sample using other methods.
This research effort is part of the Norwegian Polar Institute's centre for ice, climate and ecosystems (ICE) glacier programme that is studying the physical and biological systems associated with tidal glaciers, which is linked to the TIGRIF project, financed by the Norwegian Research Council and lead by Dr Jack Kohler at the Polar Institute.
As mentioned above, we also take the opportunities presented to take biopsies from the larger whales encountered in our travels.
For this sampling we use a crossbow with special arrow heads that take a skin and blubber biopsy. Similar to the white whale tissue samples, this material will be used for dietary, ecotoxicology, and genetics studies.
We currently have little information on the stock identity of the blue (fin and humpback) whales that summer in Svalbard, and nothing is known about how their changing status in the archipelago (longer stays in new areas) is affecting the whales that live in the area year-round.
So all in all, we have had a wonderful, successful field season with lots of new and exciting data collected. Our whole team has done a great job – in high spirits throughout the trip!
Kit & Christian