World’s Coolest Coworkers: David Rosen partners with sea lions

By Carol Patterson

It’s hard to decide if Dr. David Rosen is more like James Bond or Dr. Doolittle. His coolest coworkers are free-swimming sea lions carrying enough gadgets for an action hero while Rosen deciphers the secrets of west coast wildlife.

Rosen grew up in Toronto and started his career with a degree in biology at University of Guelph. Perhaps an unusual location for someone fascinated by marine mammals until one realizes it is equidistant to Canada’s three oceans and has employed some of Canada’s most esteemed marine mammal experts.

Pursuing Masters and Ph.D. degrees Rosen moved to Memorial University of Newfoundland. There he got involved in the harp seal controversy, eventually switching coasts to work on another political issue, this time involving Stellar sea lions and pollock populations. 

In 1995 he settled in Vancouver, splitting his time between UBC and the Vancouver Aquarium, an Ocean Wise initiative. Now his day may start with a boat trip up Burrard Inlet with one of his sea lion coworkers.

Based at Ocean Wise‘s Open Water Research Station are four free swimming Stellar sea lions that leave their pens to help scientists. Rosen develops the research question and Sitka, a 21-year-old sea lion, and her sea lion coworkers help solve it.

Trainers look after animal husbandry and interact directly with the sea lions while scientists focus on research. “When we start a project we talk about what do we need from the science side and what can the animals do,” Rosen stressed on the need to balance animal capabilities and research objectives.

Before each experiment Sitka dons a vest carrying equipment to measure things like dive depth, speed, or water temperature. She’s then released into the ocean on site.  Studies vary but Rosen may try to determine how the depth or number of fish influences diving behaviour or energy expended.

Open water research with trained animals bridges knowledge between wild and aquarium populations. “It makes sense to most people if you want to know what’s happening to wild populations you go out to the wild and study those animals but there are two problems. One, all you can do is observe. You can’t test (your observations). And two, it’s not easy to study large marine mammals in a lot of ways,” Rosen explained on the role his research fills. “The open water testing lets you test those guesses you’re making in the wild.”

At the end of his experiments, the sea lion returns to the boat for the ride home. Not because of food rewards – Rosen said sometimes the sea lions swim through salmon runs where food is abundant – but because of the bond between pinniped and human. Trainers work with the sea lions every day to build trust and consistency.

The Open Water Research Program has run for over a decade and has never lost an animal although there have been delays when a sea lion isn’t finished exploring. “We’ve sat out there until dark. It’s not like they take off. It’s like a kid in the toy store. They don’t let you out of their sight while they look around.” 

Visitors at the aquarium can see this bond during public education programs. The eyes of each sea lion are locked on their trainer and their hand signals or whistles. “Every move has a purpose,” explained Troy Neale, Assistant Curator of Marine Mammals, “to check the animal’s physical conditions or to take blood for medical tests.”

The Vancouver Aquarium has evolved from tourism attraction to conservation leader. “We were an aquarium that led conservation initiatives (like Ocean Wise seafood or Great Canadian Shoreline Cleanup). Now we’re a conservation organization that happens to own an aquarium,” explained Derek Jang, Manager, Interpretive Delivery at the Vancouver Aquarium, An Ocean Wise Initiative. 

Research from Dr. Rosen helps meet Ocean Wise’s conservation objectives. “It allows you to test those guesses that you might have in the wild. I can take those animals in a laboratory setting and manipulate their environment in a known way, whether that’s the fish they are eating or the temperature of the water. I can also develop techniques that you can apply with wild animals. If I learn that an animal is eating too much fish or not enough of another kind of fish, how does that show up in its blood and what does that mean. Then we can take blood samples of wild animals and we know what that means.”

Rosen wants visitors to see the animals as individuals. “These are impressive animals that are living in our oceans and are under threat. It’s one thing to read about it in the newspaper or to hear about it but until you encounter those animals you don’t really think about what it means to the individual animal living in the real world.”

For people who visit the aquarium Rosen hopes they learn, “the way we manage our oceans can have huge long-term impacts on marine mammal populations. We need to be take a more proactive approach of considering the possible impacts of our actions on the health of our oceans and try to avoid it rather than keep going until it’s something negative.”

Rosen and his free-swimming sea lions are offering hints on what it takes to survive in our changing oceans and recent changes to his role means he is learning from even more species.  “I’m not just working with the fur seals and sea lions which I have done for ten or fifteen years. There’s a whole new set of animals I get to work with – penguins and walrus and arctic fish. Everything is new for me and quite fun. The more different animals (I work with), the better my day! ”

Dr. Doolittle might agree.