Seals and sea lions: What’s the difference?

There are a few tricks to tell the difference between these two animal groups

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September 13, 2017
Katie Sweeney

Biologist

 

Now that we have started seeing reports of northern fur seal sightings from citizen scientists in our remote camera images on Steller Watch, I thought this would be the perfect time to discuss the differences between seals and sea lions! Northern fur seals add a bit confusion as they have “seal” in their name but, are they true seals? The short answer is, “no!”

Pinnipeds can be found in waters all over the world, even some lakes!

Here’s the long answer…

Pinnipeds (or suborder pinnipedia, which means “feather-” or “flipper-footed”) include three different groups of animals: walrus (the Odobenidae family), seals (Phocidae family), and sea lions (Otariidae family). The walrus is the only species alive in the Odobenidae family and can be found throughout the arctic (North Pacific and North Atlantic Oceans). They are one of the largest pinnipeds and actually have air sacks in their chest that they can inflate to help them float, much like a life jacket (reference: Marine Mammal Center)!

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Generally accepted classification of the carnivora order. These sorts of classifications can change over time as new fossil and DNA evidence becomes available.

Seals, or ‘phocids’ (sounds like “faux-sids”), are often referred to as true seals or earless seals. They do in fact have ears though no external ear flaps, just small holes on either side of their head. Phocids also have small front flippers and while on land, galumph, or “inchworm”, to move around. At-sea, they use their hind flippers to propel themselves.

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This is a great infographic showing different phocid species. Created by Peppermint Narwhal (via Facebook).

Sea lions, or ‘otariids’ (sounds like “oat-a-ry-ids”), are often referred to as eared seals include both sea lions and fur seals. Otariids have external ear flaps and large front flippers that they can rotate around and down in order to stand upright and “walk” on land. At-sea, they mostly use their large front flippers to propel themselves through the water. Fur seals do differ a bit from their fellow sea lion otarrids in that they have longer flippers and thicker fur. So, both northern fur seals and Steller sea lions are otariids and not phocids, or “seals”! Check out the images below of a northern fur seal pup and Steller sea lion pups showing those external ear flaps and upright posture and rotated flippers.

Pinnipeds can be found in waters all over the world, even some lakes! You may notice that there aren’t many species that inhabit warm tropical areas around the equator, though there are a few.

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National Geographic infographic of pinniped species worldwide distribution (1987).

We will be sharing more about these northern fur seals in Alaska that many of you may start to see at Cape St. Stephens (Kiska Island) in remote camera images. There is an interesting project happening right now that I will share more about in our next blog post!


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. 

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. 

Gearing up for the field season

We heading off to Alaska and we will be back in August!

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June 6, 2017
Katie Sweeney
Biologist

 

The office has been humming with energy lately. It’s that time of year, the field season is just around the corner. Spring and summer are busy times at the Alaska Fisheries Science Center. This is the time of year when the Center conducts the majority of its field work. Weather in Alaska over the winter isn’t conducive to getting work done, though summer weather offers no guarantees, either!

While we’re away, we will be putting the Steller watch project on hold starting June 20th. Since we won’t have internet while we are in Alaska we can’t respond on the Talk Forum but don’t worry! We’ll be back in August with many more images and stories to share with you all.

Some of the Center’s research trips this year include bottom trawl and hydro-acoustic groundfish surveys, marine mammal aerial surveys in the Arctic, harbor seal vessel surveys, Cook Inlet beluga aerial surveys, and vessel surveys to deploy passive acoustic recorders to record marine mammal sounds. Along with Steller sea lion surveys, our program will also conduct several studies on northern fur seals.

We have four Steller sea lion trips planned, similar to our efforts in 2016. And like all the field work at the Center, these trips require a lot of preparation. It is a coordinated effort to ensure we have everything we need since we will be isolated in very remote places and can’t just run to the store if we forgot something. Here’s a little background about each of our Steller sea lion trips:

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One of our featured bloggers, Katie Luxa, has been working with other biologists to accomplish the large task of packing and preparing gear to be shipped up to Alaska to our remote field camps. They have also been preparing the week-long training class for the seven biological observers who will be living on two uninhabited islands (Ugamak and Marmot Islands) for almost two months. The field campers will live in rudimentary shelters with limited electricity, no internet or cell phones, and no running water. They will be perching above sea lions, going unnoticed to collect data on marked animals and sea lion behavior.

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One of the trips I will be participating in will be our annual research cruise on board the U. S. Fish and Wildlife Service (USFWS) Research Vessel (R/V) Tiĝlax̑ (pronounced TEKH-lah; Aleut for eagle). For two weeks, 13 people from the Alaska Fisheries Science Center will call this 120 foot vessel home. Every summer, six skilled USFWS crew members operate this vessel, a vital platform, for nearshore research along the Alaska Maritime National Wildlife Refuge.

During our trip, the primary goal is to study sea lions to collect population counts, service our 20 remote cameras and download images (more images to come for our citizen scientists team members!), look for marked individuals, and mark individuals for on our ongoing research project. Along with sea lion biologists, there are two fish biologists who will dropping an underwater camera near sea lion sites to get a better idea of the available prey. There will also be two killer whale biologists on board looking for killer whales and other species of whales.

hexacopterTo prepare for this trip, I’ve been working with our other remote pilots to test out our new camera mount, called a gimbal, mounted to our hexacopter (or drone). The gimbal mount ensures that the camera will always point directly down and over the sea lions no matter how much the wind causes the hexacopter to tilt. I’m excited to see these mounts in action! We also have a new person on our team who you heard form in our last post about the NOAA Corps. LTJG Blair Delean will be heading up to Alaska with us for the first time to help with hexacopter surveys.

Aerial survey

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Biologists (and featured bloggers) Lowell Fritz, Josh Cutler, and Katie Luxa will be heading out on the annual aerial survey. The team will meet up with NOAA Aircraft Operation Center flight team and Twin Otter aircraft in southeast Alaska. They will survey along the coastline, capturing images of sea lions hauled out on land at known sites.

The aerial survey team assembled and tested our camera mount that holds three cameras; it will be installed on the NOAA Twin Otter. Now we know it’s working fine, I’m packing up all the gear to ship to Alaska.

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After the aerial survey and research cruise, Katie Luxa and I will meet up in Dutch Harbor (Unalaska Island) for our final survey. We will be on board a small boat for six days, checking out nearby sea lion sites for marked animals.

While we’re away, we will be putting the Steller watch project on hold starting June 20th. Since we won’t have internet while we are in Alaska we can’t respond on the Talk Forum but don’t worry! We’ll be back in August with many more images and stories to share with you all. Thank you all for your contributions classifying so many images before we head out. It’s been a joy to share our research with such dedicated people and we are so happy to have you as apart of our team!

Wish us calm seas, clear skies, low winds, and many sea lions!


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. 

Service Meets Science

The life of a NOAA Corps officer

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May 24, 2017
LTJG Blair Delean
NOAA Corps Officer

Unmanned Aerial Systems (UAS) have recently become a major tool for studying wildlife. UAS allow scientist to capture aerial imagery of marine life in remote locations with more flight flexibility, and at lower cost than most manned aircraft missions. As a Lieutenant (Junior Grade; LTJG) in the NOAA’s Commissioned Officer Corps (called “NOAA Corps”) and recently designated UAS Pilot in Command at the Alaska Fisheries Science Center, I will be traveling to the Aleutian Islands this summer to study Steller sea lions using UAS. This is the same research cruise that members of the Steller Watch Project research team will be a part of to collect remote camera images.

The NOAA Corps today consists of a team of professionals trained in various scientific disciplines who operate NOAA’s ships, aircraft (like the annual Steller sea lion aerial survey), conduct diving operations, manage research projects, and serve in staff positions throughout NOAA offices.

The NOAA Corps is one of the Nation’s seven uniformed services comprised of 321 officers who serve throughout NOAA’s line and staff offices to support virtually all of the agency’s programs and missions. TheNOAA Corps traces its roots to the former U.S. Coast and Geodetic Survey, which originated in 1807 under President Thomas Jefferson.

The NOAA Corps today consists of a team of professionals trained in various scientific disciplines who operate NOAA’s ships, aircraft (like the annual Steller sea lion aerial survey), conduct diving operations, manage research projects, and serve in staff positions throughout NOAA offices. NOAA Corps Officers are primarily stationed in the continental United States; however, there are some positions located as remotely as Antarctica, Hawaii, and the Samoan Islands in the South Pacific.

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NOAA Aircraft Operations Center in Florida

Currently, officers operate 16 research vessels which are strategically stationed at various locations around the country. These places include Norfolk, San Diego, Gulf of Mexico, Pacific Northwest, and Honolulu which is where I was last stationed before my assignment to the Alaska Fisheries Science Center in Seattle. The ships are crewed by both NOAA Corps Officers and civilian wage mariners to serve NOAA’s fisheries, hydrographic, or oceanographic missions. The aviation component is comprised of both manned and unmanned aircraft systems operated by Corps officers stationed at the Aircraft Operations Center in Florida.

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My BOTC class on graduation day.

My path to becoming a UAS pilot for NOAA began following my graduation from the Basic Officer Training Class (BOTC) at the United States Coast Guard Academy in the spring of 2014. I was then assigned to the NOAA Ship Oscar Elton Sette in Pearl Harbor, Hawaii. While on the Sette my primary duty was to drive the ship, manage scientific operations, and to serve as the Navigation Officer. Some of my other responsibilities included being the environmental compliance, dive, and property officer. We sailed the main Hawaiian Islands and beyond through the remote Northwest Hawaiian Islands which extend 1,200 miles from Kauai.

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The NOAA Ship Oscar Elton Sette off the coast of Laysan Island in the Papahanaumokuakea Marine National Monument (Northwest Hawaiian Islands).

In the fall of 2016, following my tour on the Sette, I was assigned to the Marine Mammal Laboratory at the Alaska Fisheries Science Center in Seattle, WA. This is when I became involved in UAS operations. I completed the Federal Aviation Administration’s remote pilot exam, followed by the UAS manufacturer training, and then received my UAS Pilot in Command designation from NOAA. Since obtaining my PIC designation I have completed a few practice flights with the scientist UAS team here in Seattle in preparation for the upcoming Steller sea lion field research cruise in the Aleutian Islands this summer. I’m looking forward to my first trip to Alaska—it will be a big change from Hawaii.


I graduated from the University of Maryland, College Park with a degree in Environmental Science and Policy, Marine and Coastal Management (2010). While in college I also played baseball for the Terps, and completed an internship at the Cooperative Oxford Laboratory in Oxford, Maryland. Following graduation (prior to the NOAA Corps) I worked as a contracted Special Investigator for the Office of Personnel Management, and as in intern at the White House Council for Environmental Quality in Washington, D.C.

Discovering the secret lives of Steller sea lions

Where do sea lions go when they’re not onshore?

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May 9, 2017
Brian Fadely
Biologist

 

Our remote camera images give us insights about sea lion behavior onshore, but where do they go when they’re at sea? To better understand why their numbers are declining in parts of the Aleutian Islands, we need to know where Steller sea lions forage (or hunt) for their prey that consists of fish and squid. Due to our concern with declining pup births, we are focusing on monitoring adult females’ hunting patterns while they are pregnant, and may also be nursing a pup.

The best way to track an individual sea lion’s movements and dive behavior is by using satellite-linked transmitters, also known as satellite tags. The tags are slightly larger than a deck of cards and allow us to see where sea lions go, how deep they dive, and when they come to shore. This information is saved to the tag, then up-linked to satellites (via the Argos satellite location and data collection system) so we can download the data later when we’re back at the office.

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Looking out the back (aft) window of the ship towards Attu Island on a day we wish wasn’t so typical. Photo credit: Aaron Christ

The best time to attach tags on females is complicated by their biology and the weather in the Aleutians. Sea lions shed their fur from August through November. That means if we attach a tag before she has molted, the tag will fall off with her shed fur. Unfortunately, large storms and typhoons tend to kick up after September, and the high seas and strong winds can keep us from being able to work. By November the storms intensify through winter. So, we schedule our trips during October when many of the females have already molted and storm activity is just beginning.

Attaching the tags onto the animals is a coordinated effort to minimize any impacts on the sea lions and any risks to the researchers who must get close to adult females that weighs more than 800 pounds.

Attaching the tags onto the animals is a coordinated effort to minimize any impacts on the sea lions and any risks to the researchers who must get close to adult females that weigh more than 800 pounds. We work with colleagues from Alaska Department of Fish and Game, University of Alaska Fairbanks, and the Vancouver Aquarium to safely capture and handle the adult female sea lions. It can take up to 12 scientists to have the expertise necessary to safely capture, sample, and attach a satellite tag.

Similar to our summer research cruises to look for marked animals, we visit known sea lion sites and take the inflatable skiff to shore to drop off the team and heavy gear. The problem with finding animals during October is that they are a lot harder to locate than they are during the summer breeding season when they gather on land in larger numbers. But your work classifying remote camera images on Steller Watch, helps us pinpoint the most popular sites.

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Gear schlepping processional across Amchitka Island. Photo credit: Kimberlee Beckmen

Once we arrive near a site with a good number of females, we find a safe place to land, which can sometimes be up to a mile away. The whole team hikes and climbs to a staging location and the scouting begins. A few people, including a skilled darter, will sneak up to get a closer look, searching to maximize our chances for a successful capture. When all the conditions are just right, sedatives are loaded into a dart that will be delivered from C02-powered rifle.

It takes a lot of stealth and patience to slowly sneak in for the perfect line-up. Steller sea lions have great sensory capabilities. That means if they smell, see, or hear you, they will head into the ocean. Once in position and a female is in a good location, the skilled darter will take the shot and the dart—essentially a flying syringe—launches and hits, the sedative is delivered immediately and the dart falls out.

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A puff of C02 launches a dart filled with sedatives on Kiska Island. Photo credit: Martin Haulena

The rest of the team hears the good news on the radio call and waits about 10-minutes for the sedative to kick in. The veterinarian and a few others are the first to approach the adult female. The veterinarian administers gas anesthesia and as soon as she is assured that the animal is doing well, she gives the OK. Suddenly the team erupts into hurried and quiet movements and a lot happens very quickly and efficiently to ensure safety of the sea lion and keep the handling time as short as possible.

I immediately get to work on attaching the satellite tag on top of her head—the best body location to maximize satellite up-links. First, I clean and brush the fur to remove dirt and loose fur, then I align the tag for good fit, and finally I use quick-setting epoxy to glue the tag to the fur. In the meantime other biologists are taking measurements and samples for laboratory analysis that will allow us to assess her physical condition, health, and whether she has any diseases or contaminants. She is marked for future identification, just the like the animals you see in the remote camera images. When everyone is done, we clear away and the veterinarian administers the reversal agents to counteract the sedatives, and removes the gas anesthesia device. The female starts to wake and rather quickly is up and on her way, usually to the water, as we all watch, hidden from her view.

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Here I am positioning a satellite tag amidst a flurry of measuring and sampling activity. Photo credit: Michael Rehberg

Between 2011 and 2015, 13 adult females have been captured and tracked in the Aleutian Islands; you’ll see them in the remote camera images marked with an equal sign (“=”) and numbers, from 25 to 36. We’ve had great success with the satellite tag data—we even tracked one female up to 254 days! This information offers insights into their behavior leading up to when they give birth in the following summer breeding season. Adult female Steller sea lions in the Aleutian Islands have shown a diversity of foraging behaviors, from remaining exclusively nearshore on short trips, to trips of over 260 miles (420 km) offshore and lasting six days.


I am a research wildlife biologist with NOAA Fisheries Alaska Fisheries Science Center in Seattle, in the Alaska Ecosystems Program where I’ve studied Steller sea lions and northern fur seals since 2000. My primary research interest is vertebrate physiological ecology, which at NOAA Fisheries translates into studying sea lion foraging behavior, health status, and body condition to help address conservation questions and wildlife management issues.