More Amazing Diving
In our recent PolarConnect events, we've gotten a lot of questions about what we're seeing underwater. It's very clear to us that you are all interested in the sights and sounds beneath the ice. Here are a few stories and pictures from recent dives.
Seals
It's been a very active season for seeing seals in the water under the ice. It seems like almost every dive includes a seal sighting, or lots of seal sounds. Under the ice the seals make these amazing sounds. Scientists think that a lot of these sounds are used for communication. There is a loud repeating thump sound. There are also lots of higher pitched squeaks and squeals. These sounds may indicate "This is my turf", or "Hey, who are you?". There are even some sound waves which you seem to feel, rather than hear. Perhaps, they're outside the human hearing range.
This Weddell seal swam right by Diver Steve Rupp. (Photo courtesy of Steve Rupp)
Listen to the audio in the movie clip below to hear some of the seals.
On two very recent dives I saw some seals do some amazing things underwater. First, Dr. Marsh showed me two young seals sort of wrestling underwater. We think they were just playing around, but to watch them move that quickly and gracefully reminded me that I am an awkward visitor in their world.
Can you find the Weddell Seal in this photo? (Photo courtesy of Adam Marsh)
The second encounter occurred while we were collecting some Spiophanes. I was swimming the buckets back to the down-line. A seal came in out of the deep water, and right up to where I was at the base of the Jetty (large stone pile) in 80 feet. Again, real close, like 7-10 feet away. There were two rocks, that sort of made a chair (one horizontal and one vertical). The seal sort of sat vertically in them and rubbed his back against the upright one. This went on for a couple of minutes. Then he continued swimming right up the Jetty. Unfortunately, my hands were full of buckets and no camera!
This is a good look at the Weddell seal. In the water they are graceful and fast! (Photo courtesy of Steve Rupp)
Worms
We are, of course, still focused on observing and collecting our worms. Dr. Marsh has made several big collections and I got to assist with one! The worms we collected are called Spiophanes and you can actually see their tubes on the sediment surface. It looks like this.
Here's a look at the Spiophanes tubes that we see on the bottom. (Photo courtesy of Stacy Kim)
More Spiophanes tubes. The blue circular objects you see are clam siphons. The clam is buried in the sediment. All you can see is the top of their siphons. (Photo courtesy of Stacy Kim)
Iceberg Damage
One dive site that we visited looked like it had been damaged by an iceberg recently. We saw lots of shells from dead clams (Laternula). It was interesting to see how some organisms were moving into the area to begin eating and breaking down the remains of the organisms that had died as a result of the iceberg.
Drs. Marsh and Kim think an iceberg struck the bottom here and that's why we see all the clam shells and animals breaking down dead organisms. (Photo courtesy of Stacy Kim)
Lots of digesting going on as these sea stars and nemertean worms break down the dead organisms. (Photo courtesy of Stacy Kim)
We think this photo shows a brine channel, running along the ground. In areas like this, the water is super salty. Maybe that's why these Cliona didn't survive. (Photo courtesy of Stacy Kim)
Jellyfish
We have seen a few different types of jellyfish, with all of their adaptations on display. Some of the jellyfish have been quite large. It is beautiful to watch them swim through the water.
Take a look at these photos. Can you recognize any structural adaptations that the jellyfish has?
We've seen several big jellyfish. (Photo courtesy of Stacy Kim)
Look at how the jellyfish swims. So beautiful! (Photo courtesy of Stacy Kim)
Larval Fish
All the divers have commented on how many small fish we are seeing at many of the dive sites. Some of these fish can be seen down at the bottom, living in the sediment. Some fish have been see up in the brash ice, in the very shallow water. Some have even been seen out swimming a bit, just off the bottom or just underneath the sea ice. Drs. Marsh and Kim think that it might have to do with all the sunlight that penetrated the water when the sea ic broke out last year. It was the first time in a little over 10 years that many places received direct sunlight with no ice above it.
Dr. Marsh under the sea ice crack at a dive site called Cinder Cones. (Photo courtesy of Stacy Kim)
Mike, under the ice, with the sea ice crack in the background. (Photo courtesy of Stacy Kim)
Here's a great video that Steve Rupp took to show you one of our recent dives and some active small fish. Very cool!
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