Field Journal: Pacific Nearshore Project Alaska Expedition, Day 7
Editor's note: During the Pacific Nearshore Project 2011 Alaska Expedition (see "Alaska Sea Otter Expedition Investigates Coastal Health"), researchers shared stories about their shipboard life through journal entries posted on the USGS Western Ecological Research Center Web site. This entry for Day 7 is by Tim Tinker, USGS research wildlife biologist and a co-leader of the expedition.
By the end of the first week of a research cruise, the whole crew tends to "find its groove," with the initial bugs getting worked out and group dynamics settling in to that of a comfortable extended family.
Today was another fun and productive day, and we passed an important milestone: 30 sea otters have been captured, studied and released; we have 50 feeding observation bouts collected; and all fish sampling is complete. [A "bout," or "forage bout," consists of data collected as a sea otter makes a series of dives during one feeding session; for this study, a set of data collected during five or more consecutive dives per individual sea otter was counted as a "bout."] A combination of a highly experienced and skilled crew, cooperative weather, and a dash of good luck have allowed us to finish all tasks for the northern study site a day ahead of schedule, so tomorrow we will begin travel to our southern study site, Whale Bay.
As one of the co-leaders of the expedition, my role is to be sort of a "jack of all trades," focusing on collection of sea otter diet data but also helping out with all other tasks as needed. Today for instance, I was the boat handler for a dive capture crew in the morning, "tended nets" in the afternoon—we extracted four otters that had been safely captured in these floating tangle nets—and finished the day by helping the vet crew back at the Alaska Gyre with measurements and sample collection from the anesthetized otters.
Yesterday, I was on "feeding-data duty," and so I headed over to a tiny islet that I knew had a perfect look-out spot for sea otter observations. After stern-anchoring my skiff (so that it rode the waves safely offshore) and then scrambling up the craggy cliffs that ringed the island, I was rewarded by a spectacular view: an archipelago of picturesque islands dotted the ocean nearby, while the Brady Glacier and Fairweather mountains loomed in the background. Kittiwakes and bald eagles wheeled overhead, a large male Steller sea lion thrashed a salmon in the surf below me, and a humpback whale broke the surface in the distance.
Scanning around with binoculars I saw a couple of feeding sea otters, including a mother and large pup about 500 yards away, so I quickly set up the telescope, grabbed my stopwatch and notepad, and started recording data:
Dive 1: 118 seconds submerged, 72 seconds on the surface, 1 butter clam (size 2b) and 4 soft shell clams (size 1c), 2 of which were shared with the pup.
Dive 2: 127 seconds submerged, 102 seconds on the surface, 3 soft-shell clams (size 1c) and 1 helmet crab, size 2a.
And so it continued, dive after dive, otter after otter, until I had recorded over a hundred dives from six different animals. By late afternoon most of the sea otters in the area had finished their feeding and rafted up, with about 20 nestled in a hidden cove on nearby Three Hill Island. I hailed a dive crew on the VHF radio, letting them know I had a suitable "target" for capture, and 10 minutes later one of our skiffs glided into view with Mike [Kenner, USGS] at the helm and Jim [Bodkin, USGS] and Ben [Weitzman, University of California, Santa Cruz] eager to dive.
To avoid alerting the otters to their presence, they anchored up the skiff behind a headland and quickly suited up. I was able to guide the divers into the cove by providing them with radio instructions at each of their "head checks." [Capture divers must stay underwater as much as possible to avoid spooking otters. Occasionally, divers have to surface for a "head check" to make sure they're still swimming in the target otter's direction, before diving down again.]
Within minutes, I was rewarded by the sight of two Wilson traps breaking the surface simultaneously under two of the otters: they had made a text-book double capture.
All in all a perfect day, and as I started the climb down to my skiff I startled a sleeping river otter: unknowingly we had both been sharing the same small island for the last few hours.
To read more about the expedition, see “Alaska Sea Otter Expedition Investigates Coastal Health,” this issue, and visit http://www.werc.usgs.gov/project.aspx?projectid=221.
in this issue:
Field Journal: Pacific Nearshore Project Alaska Expedition