What You Otter Know About Sea Otters - Part 3
The last week in September is known as Sea Otter Awareness Week throughout California. To bring more attention to the issues surrounding the sea otter and its ongoing recovery from near extinction, we interviewed Tim Tinker, USGS lead sea-otter researcher. Video also provided in the Transcript/Links section.
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Paul Laustsen: Welcome to the final in the three-part USGS CoreCast series discussing the California Sea Otter with Dr. Tim Tinker.
Wow! You really done your part this week to increase sea otter awareness, Tim.
Tim Tinker: Well, thank you very much. It’s been a pleasure.
Paul Laustsen: You have a lot of cool equipment in this room. How have new technologies affected your research?
Tim Tinker: New technologies have really greatly changed the way that we study sea otters and many other marine species. Clearly, try to study a species of animal that lives most of its life beneath the water and so therefore, out of sight to human eyes poses some unique challenges. It’s quite a bit different than studying a terrestrial species that you can follow around all day long. And technologies have greatly increased our ability to do that.
One example with sea otters is radio telemetry. This is not terribly new. This began to become important about 20 years ago. By implanting sea otters with these small little radio transmitters that we can monitor from shore or from airplanes, we’re able to follow individual animals over about a two to five-year period. And look at their individual behavior, their movement patterns or habitat use and ultimately when they die, we can recover them and find out what they died from.
So, telemetry based technologies have been really important allowing us to learn detailed things about the behavior and the life history of marine animals.
Another newer piece of technology that’s helped us learn a lot more is biologging technology and in particular something called a time depth recorder. This is a small little instrument that we implant into a sea otter. We have to implant it in a sea otter because we can’t attach anything to the outside of a sea otter because their so reliant upon their fur for thermal regulation.
We implant this little instrument and it collects really detailed data on the dive behavior of that animal. It records the depths and time and also the internal temperature of the animal at two-second intervals for about a year. We then can recover that instrument and that gives us a really in depth look into sort of the life of that animal. We see every dive that it’s made over a year’s time. We can see when it’s foraging, where it’s foraging, how deep it’s foraging. When it’s resting, when it’s traveling, when it’s interacting with other animals.
When we put that together with the geospatial data, we get from the radio telemetry instruments and with the direct observational data, we get by looking through telescopes. And watching these animals in their day to day life seeing what they do and what they eat, it really gives us a more and more detailed understanding of how see otters are surviving in their environment. And how they’re being exposed to the different risk factors that lead to the increased mortality that are preventing full population recovery.
Paul Laustsen: Are you looking forward to any specific technologies?
Tim Tinker: Oh, definitely. Definitely. There’s a few different areas where we hope to see technology opening up new areas on information to us over the next couple of years. One is sort of an update to the telemetry instrumentation that we currently use. We’re hoping to get to further develop instrumentations so we can get better geospatial data on the animals. Either using satellite telemetry or potentially a cellphone type instrumentation that actually uses existing cellphone networks to broadcast geospatial data for where the animal is. Or potentially, just better VHF type technologies where we’ll be able to really get a more detailed and comprehensive picture of the animals movements in the environment.
But another whole branch of technologies that is becoming more and more important for sea otters and other species are our molecular based technologies. That tell us a lot about what sea otters or what other animals are eating and essentially how they’re making their living.
So to give you an example, stable isotope technology utilizes the specific patterns of stable isotopes of carbon and nitrogen that all of us get when we consume things from the environment. There’s particular signatures, molecular signatures, that can tell us where we’re getting the food we’re eating. So for instance, if you consume a diet of spinach that’s grown in Central California or if you could eat a diet of meat that’s been grown in the mid-west, you’ll have very different isotopic signatures.
In sea otters, all we need to do is pluck one single whisker from that and then look in great detail. We can see a really detailed picture from that of what the otter has been consuming and how that has changed over time because the whisker grows slowly over probably over a year of time. So we can have a year in the diet of that animal recorder perfectly in its whisker. So it’s very non-invasive way of collecting a lot of information.
Some other molecular techniques, including fatty acid profiling, we hope to put these together to really improve our ability to understand the diets of sea otters. And therefore, learn how they are contracting the various pollutants and pathogens that seem to be affecting their mortality.
Paul Laustsen: Is there anything else that you think people should know about sea otters and your work?
Tim Tinker: Well, if there’s one thing that I can emphasize, I guess, about our research program here, we’ve more and more come to understand that sea otters give us a unique opportunity to understand the functionality of an ecosystem. In this case, the nearshore marine ecosystem, an area that’s particularly sensitive to human impacts. In particular, somewhere like California where 20 to 25 million people live so close along the ocean.
For years and years I think there was a perception that human’s were having very little impact on the ocean because the ocean we looked out of, we saw a nice, clear blue waters. And we assumed that we weren’t affecting them in any substantial way. We’re increasingly learning that that is not the case. And that human impacts to the ocean ecosystem have been profound and in most cases unfortunately have been very negative.
The species like sea otters really are – we’ve really discovered in the last few years that they offer us a unique opportunity to better understand how these marine ecosystems work. And how we as humans are impacting the functionality of those marine ecosystems.
And they do so, in the case of sea otters, they’re really excellent sentinels of nearshore marine ecosystem health. Both because they’re relatively easy to study as compared to most other marine animals. They stay very close along the shore. We can put these instruments on them that allow us to study individual animals for years and years in great depth.
They also are highly sensitive to some of the same factors that impact humans and a lot of other species. By consuming all these different species of shellfish, they’re sort of bio accumulators. They concentrate all these different types of pollutants and types of pathogens that we’re putting in the marine ecosystem better than most other species. And they’re also sensitive as mammals. They’re sensitive to a lot of the same things that affect us.
So for these and a variety of other reasons, they really give us a unique window onto these processes. And so we’re learning to let sea otters teach us about how ecosystems work and what we can do to change the way that we interact with marine ecosystem to a more positive relationship.
Paul Laustsen: Well thank you, Tim. I really appreciate the time you’ve taken to speak to us this week. And we wish you good luck in your research.
Tim Tinker: Well thank you very much for having me on the show and it’s been a pleasure.
Paul Laustsen: CoreCast is a product of the U.S. Geological Survey, Department of the Interior.
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Resources related to this episode:
- Sea otters in action