Not so black and white

Understanding the role of killer whales in the Aleutian Islands

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August 22, 2017
Kristin Campbell

Biologist

 

As I peer through the binoculars, a jet-black, triangular dorsal fin slowly arcs over the ocean’s glassy horizon. There is no mistaking it… we found killer whales!

NOAA Fisheries. Permit No. 20465

For centuries killer whales have captured the human imagination. Although arguably one of the most recognizable species, there is a lot we still do not know about them… but we are learning! NOAA Fisheries’ Cetacean Assessment and Ecology Program has been studying killer whales in the Aleutian Islands of Alaska since 2001. As researchers, our goal is to better understand the abundance (how many whales there are), distribution (where the whales are), social structure, and feeding behavior of killer whales in the Central and Western Aleutian Islands. The information we learn about these populations can help us understand the role of killer whales within this fragile ecosystem. We are particularly interested in how, or if, Bigg’s (“mammal-eating”) killer whale predation or resident (“fish-eating”) prey competition may be impacting Steller sea lion recovery in the Western Aleutian Islands.

Transient killer whale predation on marine mammals in the Aleutian Islands has rarely been observed. However, on this year’s cruise we happened upon a predation event in-progress at Hasgox Point on Ulak Island.

During this year’s Steller sea lion cruise, killer whale biologist, Dr. Paul Wade, and I conducted cetacean (whale, dolphin, and porpoise) surveys from the highest point of our research vessel, the flying bridge. We spent hours scanning the horizon with our binoculars as our ship traveled from one Steller sea lion site to the next. When we sighted whales or porpoises we noted the species, group size, and their GPS location. This year we saw many cetacean species on our voyage including sperm whales, fin whales, humpback whales, Dall’s porpoise, beaked whales, and others. Surveys give us information about whale population abundance and distribution within the Aleutian Islands.

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When we encountered killer whales, we suspended our survey in order to collect photographs of the killer whale’s dorsal fins and adjacent saddle patch pigmentation. We are able to make an initial determination of ecotype (“fish-eating” resident or “mammal-eating” Bigg’s) in the field based on physical characteristics of the dorsal fin and saddle patch, group size, and behavior. However, photographs allow us to later confirm the ecotype designation and even identify individual killer whales from their natural markings. If conditions permitted, we launched a small vessel for closer approaches to collect tissue biopsies or deploy satellite tags.

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Transient killer whale predation on marine mammals in the Aleutian Islands has rarely been observed. However, on this year’s cruise we happened upon a predation event in-progress at Hasgox Point on Ulak Island. We observed two transient killer whales methodically “working” the sea lion rookery. The killer whales closely approached sea lion groups on the shore and in the water.

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These killer whales may seem menacing, but Steller sea lions are not defenseless! Steller sea lions are large, agile in the water, and have big teeth that could harm killer whales. Even though many sea lions were in the water, the killer whales were not successful in making a kill and eventually moved on. The next morning we observed another group of four Bigg’s killer whales at Ulak Island. This group was more active, they hunted further away from the rookery, and displayed exciting behaviors like tail slaps, spy hops, and even porpoising.

Image credit: NOAA Fisheries. Permit# 20465 MML/AFSC/NMFS/NOAA

This year we successfully deployed two satellite tags on Bigg’s killer whales. Satellite tags give us information about where the whales travel and how deep they dive, unlocking the mysteries of their daily activities. Previous satellite data from Bigg’s killer whales in the Western Aleutians has revealed distinct foraging patterns. The tagged Bigg’s killer whales made shallow dives around Steller sea lion rookeries in the early mornings and repetitive deep dives (to almost 400m!) in the evenings. This data has revealed that Bigg’s killer whales in the Central and Western Aleutians forage on both marine mammals and squid!

NOAA Fisheries. Permit No. 20465

We look forward to analyzing the data we have collected this field season (including photographs, remote camera images, satellite tag data, and survey data) and discovering more about whales in the Aleutian Islands of Alaska.


I am a volunteer researcher for NOAA’s Marine Mammal Lab studying killer whales and for the Burke Museum of Natural History and Culture studying sea otter morphology and foraging behavior. I earned my B.S. from the University of Washington in Biology. I plan to attend graduate school in marine mammal science.

Getting away from it all . . .

Returning from two months away at a remote field camp

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August 15, 2017
Molly McCormley

Biologist

 

I was one of the seven researchers who lived on a remote Alaskan island to study Steller sea lions during the 2017 summer breeding season. These field camps are important for studying behavior and vital rates (like survival and birth rates) of Steller sea lions across their range – much like what you’re doing on Steller Watch! People always ask me what it’s like to spend two months on a remote island in the Aleutians. I can honestly say that it’s some of the best months of my year!

I have just returned from my fifth summer at a Steller sea lion field camp and was stationed on Marmot Island for the first time! Picture a cabin in the middle of moss-covered woods, situated a couple hundred feet back from the beach, next to a fresh water lagoon. Can’t get more picturesque than that! Now imagine you get to wake up to birds chirping every morning and while you sip your coffee on the deck, fox kits (baby foxes) wrestle a few yards away and deer graze a little way off. Doesn’t sound too bad, huh? Those days make up for the times when the weather refuses to cooperate (heavy rain or strong wind) and fog obscures even the lagoon from view.

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I was stationed at this cabin with one other field camper. Each day, we completed a four-hour shift at a Steller sea lion rookery (breeding site). A two-mile uphill hike is required to get to this site which, depending on the day, can be amazing. However, care must be taken to avoid devils club, a spiky monstrosity, and cow parsnip (also known as pushki), which contains a photosensitive chemical – it reacts with the sun and can cause blistering or skin discoloration. Machetes are sometimes required, especially in the beginning of the season, to clear the path and we take extra precautions to avoid coming into contact with pushki “juice”.

Image credit: Koa Matsuoka, NOAA Fisheries

Once at the site, we sit about 500 feet above the sea lions, with harnesses and climbing ropes clipped into an anchor system to ensure our safety. Our location allows us to observe the sea lions without disturbing them. Using binoculars and spotting scopes, we observe and record behavior of marked sea lions, as well as any other marine mammals in the area (e.g., killer whales), disturbance events (e.g., caused by rock slides), or sightings of Steller sea lions entangled in fishing gear and other marine debris.

Most days, these shifts fly by since watching Steller sea lion behavior never gets old to me. There’s always cute pups suckling or playing together; juveniles bouncing around the rookery, sometimes sneaking milk from females who are unaware; females giving birth; and males fighting to keep their territories. Having done this project for many years, I get to see the same animals every day and sometimes across multiple years. This allows me to get to know these individuals and makes collecting data exciting. What always amazes me about these animals is their hardiness and their ability to survive in harsh sub-arctic conditions!

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One unique thing that I observed this summer was a female nursing two juveniles! It’s rare for sea lions to have two dependents, though having a juvenile and a new pup is more common on Marmot Island than Ugamak Island. However, I have never seen a female nursing two juveniles. That’s a lot of milk that she has to supply each of them. That means that this female must be very healthy, which is a great sign!

IMG_3891.jpgAt the end of the day, if it’s cold or raining, we light a fire in the wood stove to dry our field clothes and gear and get cozy inside our cabin. Our evening entertainment consists of watching the fox kits play or suckle mom, observing eagles or kingfishers perched around the lagoon, or maybe even just curling up with a good book by the fire. It’s nice to get away from the rush of normal life for a while. I count myself lucky that I get to study Steller sea lions from such an amazing location and I hope to continue this work for many years in the future!

Want to see how field camps operate in the Northwest Hawaiian Islands? Check out this blog by fellow biologists from the Pacific Island Fisheries Science Center about monk seal research in this other remote Pacific Island chain.


I am currently working towards my M.S. at the University of the Pacific studying elephant seals and their hormonal reactions to stress. I earned my B.S. from the University of California, Santa Cruz (UCSC). After undergraduate school I worked at the Ocean Institute and at UCSC’s Cognition and Sensory Systems Lab. I have worked at the Marine Mammal Laboratory’s summer field camps for the last five seasons to study Steller sea lion behavior and life history.

We’re back from the field!

And we have so much to share with you!

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August 8, 2017
Katie Sweeney

Biologist

The Steller sea lion field season is over and everyone has returned to the office, hard at work processing and analyzing data, and writing up reports. If you’d like to read all about our different trips and scientific goals for each trip, check out our previous Steller Watch blog.

I was fortunate to participate on the research cruise and the re-sight trip. Despite some challenging weather, we were very successful and productive! We also saw a lot of amazing things along the way. Though I had a great time during my four weeks away, I have to admit I’m pretty excited that I won’t have to share tight living quarters with several other people until next year!

Be sure to “Follow” our blog to see more posts over the coming weeks from biologists, field campers and volunteers who participated in this summer’s Steller sea lion field season. And, great news: you can now use the new Zooniverse app to classify images.

During the research cruise on the M/V Tiĝlâx, two big goals we had were to look for previously marked animals (like those you all are looking for on Steller Watch) and to visit a select group of sites to count sea lions. These sites were missed during last year’s Aleutian Islands abundance survey. This means, I was able to fly six sites with our new co-pilot!

We also visited three sites and marked almost 300 pups for our long-term life history study: Gillon Point (Agattu Island, “~” symbol), Hasgox Point (Ulak Island, “>” symbol), and Ugamak Island (“A” letter). Handling and working with these large sea lion pups (weighing 70-110 lbs) is a lot of work but an amazing experience. In the first image (below, left picture) you can see a pup that fell asleep while hanging in the net during weighing!

After weighing, the two pup handlers (middle picture) carefully move the pup to the veterinarian’s station where she applied gas anesthesia until the pup fell asleep. During this time, we collect samples and apply the mark (you can read more about this process here). These pups were then released to the recovery area where we kept a watchful eye to insure they were fully awake and mobile. In the right picture, you can see small square patch of fur has been shaved off. This fur sample is used to measure contaminants, such as mercury.

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Maintenance of and downloading images from our remote cameras were other important goals during the cruise: we collected 245,972 images from 17 of the 20 sea lion remote cameras. For the last two years we haven’t been able to access two of the cameras at Cape Wrangell (Attu Island) due to large waves at the landing site. If the cameras are still working well, they should still be snapping away and capturing images. The third camera was on Cape Sabak (Agattu Island). We were able to get to it but there were no images captured due to some technical difficulties. We did end up putting a new camera on Cape St. Stephens (Kiska Island) for a total of 21 cameras!

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During one of our visits to Hasgox Point we had some unexpected visitors that delayed our work for a day. Two killer whales showed up at the rookery and were swimming around for hours! While we didn’t see any direct sea lion kills, we knew these were transient, or Bigg’s killer whales (“mammal eaters”). It seemed as though they were almost practicing hunting maneuvers. The most interesting thing to see was how the sub-adult and adult males reacted; these males would jump right in the water and swim around, very close to the killer whales! If you’d like to learn more about killer whales in the Aleutian Islands, we have a post coming up from one of our volunteers from the cruise in a couple weeks—be sure to “Follow” our blog so you don’t miss a thing!

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On our way east, we were fortunate that Bogoslof Island, a volcanic island which has been erupting since December 2016, calmed down enough for us to check out (at a safe distance). The island has changed a lot since the last time we visited in 2015. It is much larger and even higher in elevation than before. Interestingly, despite the volcano continuing to erupt, there were thousands of sea birds and hundreds of northern fur seals and Steller sea lions on shore! Looks pretty warm and steamy.

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Be sure to “Follow” our blog to see more posts over the coming weeks from biologists, field campers and volunteers who participated in this summer’s Steller sea lion field season. And, great news: you can now use the new Zooniverse app to classify images (Download for Apple or Android)! We have added more images to our Steller Watch project. Please join us and help figure out why the Steller sea lion continues to decline in the Aleutian Islands.


I have been a biologist in NOAA Fisheries Alaska Fisheries Science Center studying Steller sea lion population abundance and life history for over 10 years. I am an FAA certified remote pilot and have been flying marine mammal surveys with our hexacopter since 2014. I earned my B.S. in Aquatic and Fishery Sciences at the University of Washington and my Master in Coastal Environmental Management at Duke University. 

August 1st: =30

Sea Lion of the Month

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Although you haven’t had the opportunity to see this month’s Sea Lion of the Month, you can expect to start seeing her since we just added new images to Steller Watch from the cameras stationed at Cape St. Stephens on Kiska Island. We observed this month’s featured sea lion, =30, at this site during all of our research cruises to the Aleutian Islands, including this year in 2016! We even spotted her from our hexacopter (or drone) images (right)!

During the fall female capture trip in 2014, =30 was captured at Cape St. Stephens on October 3rd. She was picked among many females because she was positioned in an ideal location to be safely darted, and was observed with a pup. She weighed an amazing 776 Ibs (352 kg), was 8.5 ft (259 cm) long, and over 5.5 ft (170 cm) in diameter, measured just under her front flippers. That is a big adult female sea lion!

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Biologists are collecting samples from and gluing on a satellite tag on =30 on October 3, 2014.

 

She was marked with an “=” (equal) sign because she was not captured and marked as a pup so we do not know her birth place. Other than the superficial wound on her lower back, she was in great shape. You can still see the scar on her side, even three years later!

 

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We captured this image of =30 on June 20, 2015 with her new pup. She still had the satellite tag glued onto her head, almost nine months after her capture in October 2014. The tag fell off shortly after.

Each time we have seen her has been at Cape St. Stephens (below, left image) and she was with a newborn pup in 2015, 2016, and 2017! Be sure to keep an eye out for =30 and her pup! According to the satellite data from her tag, she is quite the home body and will likely stick around Kiska Island.

Interested in other featured pinnipeds (seals and sea lions)? Check out our neighbors in the Pacific and their species in the spotlight, the Hawaiian monk seal! You can see their August Monk Seal of the Month here!


We will share the story of one marked sea lion each month. Be sure to check our Sea Lion of the Month page on the 1st of every month to learn about our featured Steller sear lion. You may nominate a sea lion by submitting their full mark on the Sea Lion of the Month nomination forum. Thank you all for your nominations!