Capturing ice seals is an integral part of this work, but it’s easier said than done. The Bering Sea is an extremely dynamic environment. Wind and ocean currents work together to pull and twist ice floes faster than you can imagine, changing landscapes in a matter of minutes. On top of this, ice seals are difficult to find. To avoid winds that often exceed 20 knots, they shelter themselves on ice floes with plenty of cover from both the environment and our prying eyes. However, icebergs with high ridges offered great vantage points for us to scout seals and plot our best course to an animal. To avoid alerting them, we opted to stay downwind for as long as possible and used larger ice floes to hide our boats on approach. When we were close enough to the seal (or lost our cover), we maneuvered our boats quickly and placed one to four researchers on the ice to finish the capture.
Occasionally, we were fortunate enough to capture two animals close together, which greatly reduced our time spent searching. On April 28th, while approaching an adult ribbon seal, a small ice floe to our right slowly spun around to reveal a juvenile spotted seal just 30 meters away. After we successfully restrained the ribbon seal, Skyla tossed me another net, and our boat sped over to the second animal. In less than a minute, our team had captured two different species of ice seal!
On May 21, we had one of the research trip’s worst weather days. Luckily for us, wind, snow, and swell do a great job of masking the noise of our boats. While on our way to scope out a seal that the crew of the R/V Norseman II (SVA) had discovered, we passed by a large ice floe. As we turned the corner, we came face to face with two spotted seals that were nestled up against some relief and carefully hidden. We were just as shocked to see them as they were to see us. They immediately started galumphing to the water, and without time to think we hopped onto the ice and captured two of the largest seals of the trip. One of them weighed over 250 lbs!
If a capture was unsuccessful, there was a good chance that they left behind important samples for us. Colloquially referred to as “noops” or nervous poops, fecal samples can tell us about an animal’s diet, range, and health. Because ice seals spend much of their time in the water, these samples are hard to come by and exciting to find. The scat kit was conveniently placed in my boat, so I became this trip’s “scatman” and with all of the information that we can extract from fecal samples, it was a role that I took great pride in!
Our main responsibility during a successful capture is the safety of both the seal and our team. We begin the process by transferring the animals from our long-handled capture nets to hoop nets that are designed to safely restrain them during a workup. The seals are then sedated, which helps reduce their stress and lowers the potential for them to harm themselves or us. To further calm the seal, we place a cloth over its eyes similar to a falcon’s hood, and we work as quietly as possible by turning our boat engines off and whispering if we even speak at all.
Similar to a routine doctor’s checkup or physical, we weigh the seal, measure its length, and draw blood. Data on ice seals is relatively rare, and this information will be used to create baselines of health for ribbon and spotted seals in the Bering Sea. Additionally, we use an ultrasound probe to measure a seal’s blubber thickness along several points of their body, and these values give us an indication of their fat reserves and overall body condition. Blubber is an important resource for seals, playing a large role in thermoregulation and energy storage.
Our final procedure before releasing the seal is attaching a telemetry tag. These devices communicate via satellites and are programmed to track location, dive behavior, and the amount of time spent hauled out of the water. When our workup protocol is complete, our veterinarian will reverse the sedative and give the OK for release. The blindfold is removed and we quickly back away from the animal.
On this trip we successfully caught 25 ice seals and deployed tags on 20 animals, which will give us insights into their behavior over the next year. Hundreds of samples were collected in the process, and in the coming weeks they will be sent across the country to laboratories that are studying the health and ecology of ice seals. Insights gained from this research voyage will be crucial in protecting ice seals during a period of rapid change in the Arctic. You can learn more about our findings from past surveys and this one—as the data come in—at our Ice Seal Research in Alaska webpage.
Check out some of my favorite photos from the trip below!
