 Riikka and Henrik investigate a collapsed Saimaa ringed seal den The Saimaa ringed seal, norppa in Finnish, is a subspecies of Ringed seal endemic to Lake Saimaa, in eastern Finland. Once widespread, then on the brink of extinction, it has become a tiny bit more common thanks to years of hard work: conservation started at the turn of the 1970s and 1980s, and the population has grown especially in the last ten years thanks to wider restrictions on gillnet fishing. Now, a conservation program called Our Saimaa seal LIFE, funded by the European Union and coordinated by Metsähallitus, the Finnish government agency for conservation and forestry, is developing new methods for conservation in a warming climate. In the cold season, Saimaa ringed seals dig dens inside snowdrifts that have formed on the ice. They come from underneath and use their claws to create a perfectly round hole in the ice and then carve a cavity in the snow. It’s in such a den that they rest, and that females give birth to a single pup.  In April, I joined a field survey to look for winter dens. In the team were Riikka and Mikko, from Metsähallitus, and Henrik, a volunteer. We travelled on the ice with kick-sleds, following shorelines that seals were known to use. This late into the season, much of the snow had melted already, and dens had collapsed: that’s how we could spot them, they would be invisible otherwise. That also meant the ice was thin and treacherous, and the risk to fall through it was real. As a result, we wore drysuits that would keep us dry in case we ended up into the water, and ice knives to pull ourselves out of it… a wise precaution, as we discovered later. Other equipment included spikes under our feet, for grip, and a wider base for the sleds’ skates, to distribute the weight on the soft April ice. 
 Narrows straits were often free of ice. To cross, we had to go on land. I had never used a kick-sled before, so there was a bit of a learning curve. The skates were really flexible, they tended to wobble left to right, and the whole device leaned toward a certain direction depending on what foot I kicked with. I frequently switched the latter, because my legs started to burn not long after we started. It was quite the workout! I kinda managed to keep up with the others, but I was always at the back. Throughout our trip, which lasted about 4 hours, we found a number of breathing holes, either flush with the ice with no snow around, or inside a collapsed snowdrift. We also found several bigger cavities that could have accommodated a resting seal and maybe a mother with a baby. Riikka rubbed her hand against the polished ice to find bits of fur that the pup may have left behind, but to no avail. Even if there was no sign of a baby, each sign of seal presence was carefully recorded. Saimaa ringed seals are strictly protected and sensitive to disturbance, so it’s not allowed to disclose locations. Because of that, I have obscured the maps on the images. 
  We split in two teams of two and continued our journey around skerries and peninsulas, briefly stopping for lunch in a sheltered cove. We enjoyed the sun, but the wind was cold when we were exposed to it. Bird observation were few and far between, but included a stunning pair of Western ospreys (Pandion haliaetus). Later, we scared a pair of Canada geese (Branta canadensis), and that’s where things started to go awry. We were going around scattered rocks at the tip of a headland when I saw Riikka, ahead of me, fall through the ice. It happened very suddenly: the ice broke, and the kick-sled dropped down with Riikka and her bags. That’s when I realised I didn’t know what I should do if someone else were to go through the ice! First thing first, I made sure my photography gear was safely tucked in its dry bag, inside my backpack. I left it on the sled and carefully approached Riikka on foot. I was worried that, if I came too close, I would go to the water as well… and that’s exactly what happened! It was cold for the hands, but at least we could confirm the dry suits worked well! Riikka was trying to save her bags, but I couldn’t really help while being in the water. The ice breaking under me, I carved a channel to reach thicker ice that could bear my weight, and pulled myself out. Dragging the water-filled bags out was a struggle, but we managed without cracking more ice, and Riikka used her ice knives to climb out of the water. Back to my sled, I was happy to find an extra pair of warm, dry gloves. The worst in all that? When we were in the water, we could see the Canada geese walking on the ice towards us. I could imagine them laughing at those clumsy land-bound creatures... So we backtracked and had to travel overland to reach the other side of the pensinsula, which was a whole adventure in itself! Then we continued with only 3 sleds.  Before the plunge...  ... after the plunge! Towards the end, we reached an artificial den. In January last year, I photograph a team of volunteers ploughing artificial snowdrifts for the seals (see my newsletter from March 2023). That's for situations when there is ice but not enough snow, but what if the ice is missing altogether? In a world of rapid climate change, that's a real possibility, and a dire threat for Saimaa ringed seals. That's why researchers at the University of Eastern Finland (UEF) have been developing floating structures that can provide a safe haven for the seals. They have been useful, as monitoring has proved, but the one we visited wasn't in use this past winter: one seal popped its head into the hole, but that's all the camera trap captured. 
 A camera trap on the outside helps researchers to monitor what kind of attention the artificial den might have attracted. Foxes and other predators have been caught on tape, but they never made their way inside the den. I don't think we found any definite trace of a baby seal in the whole area, even though the seals are certainly there. Could it be that the local individuals are still too young to breed? Time will tell...   Trying to save the data after our swim in the lake!
0 Comments
Leave a Reply. |
