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Alaska Ecosystems Program

Remote Observations: Studying Steller Sea Lions Year Round 

Research Reports
Spring 2014
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The plane descends into Anchorage on a typical summer day, blue skies, hot, and sunlight for almost twenty hours a day. The 3 1/2-half hour flight from Seattle, Washington, is only the first leg of the journey for Dr. Tom Gelatt and his team of Steller sea lion scientists from NOAA Fisheries Alaska Fisheries Science Center (AFSC) to participate in an annual survey of the endangered Steller sea lion.

Their destination is Adak Island in the Western Aleutian Islands – a 1,000-mile stretch of volcanic islands across the North Pacific from the Alaska Peninsula to the Russian border. After another 3-hour flight the team arrives on Adak, where the U.S. Fish and Wildlife Service research vessel Tiĝlâx is waiting to take them further westward to rookeries where Steller sea lions congregate to breed and give birth. Scientists can safely visit this area only once or twice a year due to weather and resource restrictions—not often enough, they are finding, to learn why the western portion of the western stock of the endangered Steller sea lion continues to decline.

To add to the scientists’ challenge, sea lions marked in the United States were recently observed on the Commander Islands and the Kamchatka Peninsula in Russia. Conducting research in Russian waters on a foreign vessel requires permissions that may or may not be obtained for each survey. This means the Tiĝlâx won’t travel west across the Russian border to survey rookeries on the Commander Islands only a couple hundred miles away. Instead the AFSC scientists work with colleagues at the Far East Branch of the Russian Academy of Sciences (RAS) to conduct separate surveys in Russia using Russian vessels. This requires Seattle-based scientists to fly eastward, due to lack of commercial air service from the west coast of the United States to Russia, on an 11,000-mile journey to Petropavlovsk on the Kamchatka Peninsula.

“And that is before getting on a vessel to get to the islands where the animals are.” exclaims Dr. Vladamir Burkanov, a Russian scientist who has worked with the AFSC on Steller sea lions for over 25 years. 

Every day of the two week survey is a flurry of activity while scientists collect as much data as possible at each rookery site. Arriving on shore aboard a rigid inflatable boat, scientists carefully capture a sea lion to get blood samples for genetic research or to place a satellite tag to learn about their migratory behaviors. Other scientists are on the lookout for fresh sea lion scat for later analysis to learn what the sea lions are eating.

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A remote camera system is positioned on a makeshift ledge made from reclaimed lumber.  
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Camera system batteries recharge using solar energy.
 

Scientists hike to the highest point above the rookeries to search, using binoculars, for permanently marked animals to document movement patterns and survival rates. They also count the number of pups for birth rates, and juveniles and adults for abundance estimates. But these data are only a snapshot of what is happening at each rookery. What about the rest of the year?

Dangerous weather, limited resources, and international boundaries, led the AFSC and RAS scientists to develop a system of time-lapse cameras to observe sea lions year round. To withstand the harsh Arctic winter conditions, each system begins with a top loader PelicanTM case - a watertight, crushproof, hard plastic case used by professional photographers and scientists to carry sensitive equipment, which is then customized for the fieldwork. A window is cut into one side of the case securing a pane of glass salvaged from an old scanner. On the opposite side a round hole, about the size of a nickel, is cutout to feed electrical wires to an external solar panel. These areas are sealed with a waterproof epoxy resin.  

Behind the window a single-lens reflex (SLR) digital camera is secured and powered by a rechargeable 12-volt battery connected to the solar panels. Photos are taken at a set time interval (e.g. every 30 minutes) from dawn until dusk using a timer connected to the camera. The final ingredient is a can of desiccant, added to absorb any humidity.

In the last 2 years, 78 cameras have been deployed at 18 sea lion rookeries throughout the western Aleutians of the United States and the Russian Far East. The number of cameras at each site is dependent on the size and shape of the rookery. Larger sites, sites that curve or have rocky outcroppings, have more cameras. The placement of the camera is dependent on the availability of rock outcrops to shelter the equipment from the environment and provide a wide-angle perspective of the rookery. Once those locations are determined, the camera systems are secured to salvaged lumber then bolted or secured to rocks or in some cases a modified tripod to improve the camera view of the rookery. When the scientists return each summer they collect and replace the 128 gigabyte memory cards in each camera.

“A scientist can use these photos to simulate a year-long survey at monitored Steller sea lion sites without leaving the office.” remarks Burkanov.

These camera systems have remotely capture thousands of photos without maintenance or researcher presence. In the first 2 years of the study, a third of the cameras malfunctioned due to corrosion, rats, snow fall, or operator error. One camera was lost to a 30-foot monster wave.

Remote observations using time-lapse camera systems provide a new way to collect year-round information about animal abundance, behavior, and sightings of marked individuals. This vast amount of information may help solve the mystery of why Steller sea lions in the far western Aleutians continue to decline.

By Rebecca Reuter

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