We partner with Russian scientists to study the entire western stock of Steller sea lions that extend beyond the boundaries of the United States. They monitor and maintain up to 50 remote cameras at known sea lion sites to look for marked animals.
For April, we are featuring a Russian born sea lion, M625 as our Sea Lion of the Month. She’s a popular sea lion—many of you have submitted her to our Sea Lion of the Month Nomination. She has quite the story to tell! She was born and marked on Medny Island, Russia on June 27, 2004 and weighed 64 pounds. Medny Island is a part of the Commander Islands which is located just over 200 miles northwest of the Aleutian Islands, Alaska (United States).
During her younger years, Russian scientists recorded observations of her at numerous sites on Kamchatka Peninsula. She returned to her birth place on Medny Island and gave birth to her first pup on June 13, 2010, when she was six years old. The following two years, she was observed throughout the Kamchatka Peninsula with her offspring. In 2014, she returned to Medny Island again and birthed her second pup on June 11, 2013 (when she was 9 years old). She wasn’t observed in 2014 and then only seen once in Russia in 2015 . . .
Here is where her story gets interesting. Scientists spotted her at Kozlova Cape on Kamchatka Peninsula on May 26th, 2015. The next sighting of her was captured by our remote camera on Cape Wrangell (Attu Island, US) on June 9, 2015. This same day, she gave birth to her third pup which means, in just two weeks, she traveled over 430 miles and give birth on Cape Wrangell! Aren’t these animals amazing?
We have only processed images from this site captured up to the end of June 2015 so keep an eye out for M625 and her new pup! Many of you have already been seeing her repeatedly in the images. Here’s a link to a great image reported by a fellow citizen science where you can see her with her pup (right side, middle)!
Great news: We will now share the stories of two marked sea lions (instead of just one) each month! There has been so much interest to hear the stories of marked sea lions that we need to kick it up a notch. Be sure to check-in on the 1st and 15th of every month to learn about our featured Steller sear lion. As always, you may submit the mark of your nominees to the Sea Lion of the Month forum. Thank you all for your nominations!
Searching for innovative solutions to count Steller sea lions
March 23, 2017 Katie Sweeney Biologist
The images you’re viewing on Steller Watch are from the remote cameras we placed at the westernmost reaches of the U.S., where Steller sea lions have declined dramatically. The remote cameras along with marking the animals are two research projects that are part of our mission to pinpoint why Steller sea lions in the western half of the Aleutian Islands are not rebounding like they are to the east.
In addition to Steller Watch, we just launched an effort to develop a program to automate the yearly Steller sea lion population count, our biggest and perhaps most important research project of the year. We partnered with Kaggle to accomplish this. Kaggle connects people to coders who compete to find a solution to big data challenges, saving organizations time and money. The project called NOAA Fisheries Steller Sea Lion Population Count is now live and runs through the end of June. This story was shared by the Alaska Fisheries Science Center if you’d like to read more.
Counting the Steller sea lion population is vital to monitoring the species and staying on top of abundance trends. Each summer, we head to Alaska and gear up for weeks at sea on a research vessel. Summer is best because it’s when Steller sea lions go on land, which biologists call hauling out. During the rest of the year, sea lions spend a lot of time in the open ocean.
So, how do we count? We use a handful of methods depending on the situation.
The summer months are a busy time for Steller sea lions – females give birth, begin rearing their pups and adults breed. Aggressive males stay on land and fast for months to defend their breeding territories. Even non-breeding juveniles and sub-adult males (males that are not yet sexually or socially mature) haul-out with greater consistency during the breeding season. There’s a flurry of activity at sea lion sites and scientists from the Alaska Fisheries Science Center are closely monitoring as much as possible while we count the population.
So, how do we count? We use a handful of methods depending on the situation. At smaller sites with fewer sea lions, we can count on land or by boat, either on the research vessel itself or by launching small skiffs to get a closer look. At large sites, we take aerial images from a plane or an unoccupied aircraft system, or hexacopter drone. During our 2016 survey, we collected over 20,000 aerial images that we counted 29,427 sea lions from, back at the office.
It takes two biologists up to four months to look through those aerial photos. And in those pictures, there are tens of thousands of individual sea lions, and we count and identify the age and sex of each one we count. We hope computer scientists will connect with us on Kaggle to create an innovative algorithm that can recognize sea lions in aerial photos. Automation, or partial automation, would make counting more efficient and give us biologists more time to focus on other important Steller sea lion research studies.
In our next blog, one of our biologists will share what it’s like to conduct aerial surveys in the traditional way, using a small plane.
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.
We’d also like to know what you’d like to hear about. Head to our Talk forum to post a Question for Biologists and your question could be selected for a future blog post!
The not-so-glamorous way we investigate Steller sea lion diets
March 15, 2017 Lowell Fritz Biologist
You are what you eat. That’s the basic philosophy behind monitoring the diets of wild animals. In the case of Steller sea lions, we can’t see what they are eating since they feed at-sea, so we have to investigate their diet in other ways. The most common way to find out what Steller sea lions are eating is to — wait for it — collect and analyze their feces. That’s right, we go onshore to sea lions sites, where they have hauled out and pick up after them. Here’s a picture of a group of us ready to collect scat.
Collecting scat is just like cleaning up after your dog, if your dog weighed over 2,000 pounds! We use gallon size bags for samples. A good collection of many scat samples from one site might weigh 60 lbs.
What can we learn about their diet from analyzing their scat? Well, quite a bit. Sea lions can swallow many fish, squid and octopus whole. Fish bones and squid and octopus beaks from their mouth parts, gradually make their way through the sea lion’s digestive tract. We can isolate these hard parts in the scat to identify individual prey species from just a few bones.
In the lab, the scats are washed in sieves and the hard debris left behind is cleaned and studied further under a microscope. Each solid bit is compared to other parts kept in our reference collection of known sea lion prey species. As you can imagine, it takes a lot of skill and time to make identifications from small fragments.
Hard parts left behind in sieve
At the microscope identifying hard parts
Hard parts in the reference collection
Aside from cataloging hard parts, we can also analyze prey DNA found in the soft parts of the scat. This technique is especially good at detecting prey that don’t have very many hard parts (invertebrates like squid and octopus), fish that are very large and may not always be consumed whole (like Pacific cod), and fish that have small and fragile bones (like smooth lumpsucker) that may not make it through the digestive track undamaged. But DNA studies are expensive, so, we use this technique to supplement the traditional studies of hard parts, such as a recent description of the late winter diet of sea lions in the Aleutians.
Collecting scat is just like cleaning up after your dog, if your dog weighed over 2,000 pounds!
Steller sea lions target fish that aggregate near the bottom of the ocean or in the middle the water column. While sea lions can dive a lot deeper than humans, they aren’t considered deep divers compared to other marine mammal species. Most of the prey they target live on the continental shelf in waters less than 650 feet deep — that’s still a little deeper than the Space Needle in Seattle is tall.
Steller sea lions in the Aleutian Islands have a diverse diet. In the Aleutians, there are almost 300 species of fish alone, plus dozens of species of squid and octopus. Steller sea lions consume about 50 different species, usually whatever is the most abundant fish in the area.
Here are some of the most common prey items we see in the Aleutian Islands:
Atka mackerel is one of the most abundant yearlong resident fish in the Aleutians Islands, and it also sustains the largest commercial fishery in the region. During the summer, Steller sea lions feed on enough Atka mackerel to make up more than half of their diet. In winter, the fish make up about a quarter of their diet.
Like Atka mackerel, Pacific cod are year round residents and since they grow up to 43 inches long and weigh up to 37 pounds they are probably the biggest fish that sea lions eat in the Aleutian Islands. Pacific cod are consumed more often in winter than summer. In winter, Pacific cod make up about one quarter of the sea lion diet.
Sculpins are bottom-dwelling (demersal) fish that are widely distributed on the continental shelf. Steller sea lions eat mostly red Irish lords based on our DNA analyses. They eat sculpins mostly in winter, when they make up about 15 percent of their diet.
Salmon aren’t considered year round residents of the Aleutian Islands. Steller sea lions eat mostly pink and sockeye salmon based on our DNA analyses, and they eat salmon mostly in summer.
These funny little guys are an enigma. Not much is known about their abundance and distribution, but Steller sea lions eat them far more often in winter (10 percent of their diet), when lumpsuckers aggregate to spawn, than in summer. Lumpsuckers are named for their pelvic fins that have evolved to form an adhesive disk that enables them to latch onto rocks in areas with a lot of current, like the Aleutian Islands.
Squid and octupuses:
Cephalopods are a group of invertebrates that includes both squid and octopus. Based on DNA evidence in scat, we know Steller sea lions more commonly prey on giant Pacific octopus. Cephalopods make up about 10 percent of the sea lion diet in winter.
I have been studying Steller sea lions since 1990 with NOAA Fisheries Alaska Fisheries Science Center in Seattle. My primary research interests are sea lion population dynamics, demographics, and interactions with commercial fisheries. I’ve also worked on fish during my career with NOAA, particularly species eaten by sea lions, like Atka mackerel, walleye pollock (you may know them as fish sticks and imitation “krab”), and Pacific cod. I graduated from Bucknell University (B.A. Biology, 1976) and College of William and Mary (M.S. Marine Science, 1982), and started my science career in 1982 at Rutgers University as a Research Associate. At Rutgers, I worked at the Haskin Shellfish Research Laboratory in Bivalve, NJ (down the road from Shellpile… you can’t make this up) studying the shells of mollusks living in habitats ranging from freshwater lakes and streams to deep-sea hydrothermal vents. I even had the opportunity to go down in the Alvin submersible!
*Images of Aleutian Island sea lion prey were borrowed from other NOAA Fisheries programs.
Our very first Sea Lion of the Month is ~26! She’s the ‘cover girl’ featured on the About project page. This sea lion was one of the first to be marked in 2011, when this project began. She weighed 67 pounds and was a little over 3.5 feet long—a very healthy pup!
We have seen her quite often in our remote camera images and in person during our research cruises in 2012, 2013, and in 2015—when we took the picture above.
She seems to be staying local, near her birth place at Gillon Point (star, map left) on Agattu Island. We have also seen her at Cape Sabak (on the same Agattu Island) and nearby on Alaid Island (circled stars).
We didn’t see her during our summer 2016 research cruise but don’t worry, it seems she can be elusive since we didn’t see her in 2014 either. She would be just over 5 years old which means the next time we see her, she could have a pup. Keep an eye out for her in the images!
If there is a sea lion you keep seeing and would like to know more, head to the Sea Lion of the Month Nomination forum to submit the full marking and we will try to feature that sea lion and share what we know of their story on the first of the month.
A typical day on our research cruise looking for sea lions.
February 23, 2017 Katie Sweeney Biologist
I am so excited for the launch of our Steller Watch project on Zooniverse! It’s a privilege to share our research with you all.
I’m leading the Steller Watch project but work with a team of colleagues at NOAA Fisheries’ Alaska Fisheries Science Center. I primarily work on Steller sea lion population abundance and monitoring. I did my undergraduate work at the University of Washington and earned my Master’s from Duke University.
In the About section of the Steller Watch project site, we explain that the images you’re viewing and classifying were captured from our automated remote cameras. The pictures are helping us get a clearer picture of Steller sea lion presence and behavior year-round. These remote cameras supplement our field work visits.
What’s it like to be out to sea in the far western reaches of the U.S. to survey sea lions?
Every year, we conduct a ship survey in the Aleutian Islands in Alaska to survey Steller sea lions and check up on the remote cameras. We spend weeks at sea visiting known sea lion sites to count the animals and look for the few marked individuals.
What’s it like to be out to sea in the far western reaches of the U.S. to survey sea lions? Well, when we approach a known Steller sea lion site, the captain of the research vessel navigates offshore from the location to ensure the sea lions don’t smell the ship’s exhaust. Steller sea lions have poor vision, but they have an excellent sense of smell.
From that vantage point, the team of biologists grab binoculars and look for Steller sea lions from the ship’s wheelhouse. Depending on what we see, our program leader, Tom Gelatt, makes the call to pack into the 16-foot inflatable skiff to get a closer look.
When we get the go ahead, I make my way down to the gear room, grabbing my rubber boots and flotation suit — a big orange onesie — which could save my life if I fell into the frigid waters of the North Pacific Ocean. The other biologist also suit up and one-by-one we carefully climb down the ladder into the skiff.
Once settled, we make our way towards the site. The skiff driver stops a bit offshore to make sure the sea lions haven’t detected us. That gives me time to pull out my data book, binoculars, and camera with a telephoto lens. I’m ready to capture a picture of any marked animals.
Next comes the fun part. We sit and watch. And then we watch some more. Sometimes we may have to stay out for three hours to ensure we’ve had a good look at all the sea lions. Even in rain or high winds we scan each animal, focusing our attention to their left sides (the side that has the markings) looking for the few marked individuals.
When I scan and spot a marked sea lion I grab my camera and snap pictures. Then I record the observation in my data book including details like age, sex, and behavior of the marked animal. For example, if it’s an adult female, does it have a pup nearby or suckling?
Watching these massive animals is a wonder. When we are certain we have seen all we can, we head back to the research vessel. After taking off all my gear, I’ll grab a cup of hot cocoa and take a seat while we transit to the next site, in the back of my mind, always hoping the seas will stay calm.
If you’re interested in reading about our 2016 research cruise, check out my blog from last summer. For more information about all of our Steller sea lion field work, we have an interactive story map describing our efforts in 2016.