Researchers from USGS, Monterey Bay Aquarium and other institutions are currently on a three-week expedition sailing Alaskan waters to study sea otters, as part of the Pacific Nearshore Project investigating coastal health. During their voyage, researchers will be sharing their shipboard life with us through journal entries that they’re sending home regularly.
Editor's Note: Photos in this post are from previous Nearshore Project expeditions or stock photos. The Alaska expedition team currently has limited data transfer capabilities and cannot send photo files.
Pacific Nearshore Project
Alaska Expedition Day 6 - May 22, 2011
Benjamin Weitzman, USGS research field technician
Well, it’s almost ten o’clock at the end of another long day. We are up to 19 sea otters total, safely captured and released. We dove at a few new sites today to try to start capturing from different groups of sea otters in the local area. So far, the diving has been exciting, interesting, and cold with the water temperature hanging around 40 degrees. Our drysuits at this point are starting to smell a little bit beyond pleasant, so you know that we are definitely working hard.
My capture partner, Mike, and I dove at a couple new locations near the Inian Islands. The Inian Islands are known for the intense currents that occur during the tidal changes where the velocity of water can exceed 10 knots at times. We aren’t working in the swift water area but spent most of the morning searching the coast line for resting otters.
Our shore spotters today were Jim and Tim and they found us a raft of about eight sea otters resting in a kelp bed on the outside of Middle Inian Island. We slowly worked our way into position about 300 meters away from the group of otters and donned our gear.
We need to be really sneaky when trying to catch sea otters as they are incredibly aware of their surroundings and have a very strong sense of smell, so planning the approach from downwind is absolutely key. Using standard SCUBA tanks creates a lot of noise and bubbles in the form of bubbles so we use special underwater breathing equipment called rebreathers that allow us to be bubble-less and totally stealth underwater.
Once we were ready to go we started our run, following a compass course towards our target otters. The visibility in this area is pretty variable, I’m used to 5-10 feet of clarity being standard and today we were lucky to have around 20 feet of visibility. As we cruised through the water, being towed by torpedo shaped scooters, rocks covered with all sorts of marine invertebrates and algae flew by. A harbor seal popped in to check us out, probably thinking, “what the heck are these guys?”
After about 15 minutes we arrived underneath the raft of otters. From beneath, we can only see the silhouette of the back of the otters at the surface, but just the sight is enough to get the adrenaline flowing.
In position, Mike and I nodded to each other and began our ascent. As we come up underneath the otters we grab the trigger on our specialized trap, called a Wilson Trap, and kick as hard as we can. When we break the surface, ideally, the sea otters fall into the trap, a suspended net, and we have ourselves a little bit of a rodeo while we wait for the skiff to come pick us and the otters up.
Today’s dive ended a little bit differently, instead of a head nod followed by a capture, the otters clued into us and spooked. There was one active animal in the group who woke all of the other animals up and when they looked underwater and saw us, they swam off.
The rest of today went in a similar fashion until the end of the day when we both captured a sea otter on a single dive, what we call a double. It’s the way this work seems to go, some days are good and you catch two otters on every dive, and some days the otters are just too aware or conditions won’t cooperate and you get skunked dive after dive.
Despite the lack of success today, we’ve had really good luck the last couple days and tomorrow is a new day. The entire crew is really great to work with, as everyone is always willing to help each other out. Sea otter captures need this kind of cooperation to be successful as the divers, shore spotters, veterinarians, and scientists all need each other to get the job done. It’s been a great start to what will likely be an excellent field season and I’m excited for all of the capture adventures to come!
Benjamin Weitzman is a sea otter research field technician at the Santa Cruz Field Station of the USGS Western Ecological Research Center; he is also a graduate student at the University of California-Santa Cruz.
What do sea otter tissue samples and physical health tell us about the health of our coastal waters? Explore those clues here.
Top Image: Capture divers ride propeller-scooters with a mounted Wilson trap during the 2010 Alaska expedition (Credit: George Esslinger/USGS). Middle: A montage of a wild sea otter capture from the 2010 Alaska expedition (Credit: George Esslinger/USGS). Bottom: Ben Weitzman (Credit: Ben Young Landis/USGS).
The Pacific Nearshore Project is a multinational, multiagency project investigating sea otters as health indicators of coastal waters and marine resources from California north through Canada and Alaska. The project is led by the U.S. Geological Survey with key research partners from the Monterey Bay Aquarium, Department of Fisheries and Oceans Canada, National Park Service, U.S. Fish and Wildlife Service, Seattle Aquarium, University of California, University of Idaho, University of Wyoming and California Department of Fish and Game. For a full list of sponsoring agencies, research blogposts, otter photos, please visit the project homepage at http://on.doi.gov/nearshore