Brandon Southall and Chris Clark were just profiled in National Geographic for their work on whale communication and shipping noise. Click on the drawing to check out the full story in National Geographic.
(Personally, we’re excited to see the growing profile of this issue, and consider ourselves lucky to be working with Chris and his team at Cornell on studies to assess the effects of chronic ocean noise on whales and dolphins in British Columbia.)
I’m so excited to launch our new website today. It happens to be my birthday, and this (and the chocolate cake) was the perfect gift. We love our research on whales and dolphins, and are happy to finally have a beautiful space for our work to live and grow. We hope you like it here, and visit all the time. Our goal is to have a place where we can discuss ideas with you — we publish in scientific journals, but not every story is publishable; not everyone reads scientific journals; publishing is slow; and we want to hear what you think.
What we do around here is fairly straightforward — marine conservation. Each icon links to a page on one of our research themes.
I know what you’re thinking. How did a couple of field biologists create such a beautiful website? We didn’t. The fantastic S. Joy Studios completely “got us” and what we are trying to do and designed a great place to hang out. Sarah Bray and her amazing team, Julianne Carson (@juliannecherie) and Leah Shaver (@leahcreates) are THE BEST and now know more about whale pooh than they ever cared to know.
The incredibly talented Sandy Buckley (@sandybuckley) created our “bespoke” graphics and logos. We love them (and her) so much, we’ve named a dolphin after her.
And, we were so lucky to get expert advice from Sarah’s uber-inspiring colleagues, the fabulous Gwen Bell and Kelly Parkinson.
Well, here goes.
This study, led by Erin Ashe as part of her PhD project at the University of St Andrews, assesses the health of the population of Pacific white-sided dolphins found in the Broughton Archipelago, BC and nearby waters. This is a demographic study, which means that it uses statistical methods to study a population. The statistics are important, because only the most catastrophic problems are apparent to casual observation, and the goal of conservation biology is to identify whether there are human-caused problems, and if so, mitigate them well before they reach catastrophic levels.
Come to BC and spend some time here. If you’re lucky, you will see groups of hundreds of dolphins. When people see large groups of dolphins, the obvious, superficial interpretation is that the population(s) must be thriving. But that’s not always the case. Remember when we first started hearing about “dolphin-safe tuna”? Those measures were implemented because managers were concerned about levels of bycatch of other dolphin species in tuna fisheries. Spinner dolphins are designated as depleted under the US Marine Mammal Protection Act, even though there are about 613,000 spinner dolphins. That’s a lot of dolphins, but it is less than half of what there were before huge bycatch rates in tuna fisheries. For BC’s dolphins, yes, we see hundreds of dolphins in a group. And don’t get me wrong. Abundance is a hugely important parameter to measure, and a lot of our time is spent producing good estimates of wildlife abundance: it is an essential number to have if you want to know how much fish the dolphins need to thrive, or to estimate the probability that the population will go extinct. But it is tough to detect anything but the most catastrophic population crash from the rough abundance estimates we are likely to produce for these dolphins. The population could still be declining, and no one could “eyeball” a decline from 900 to 850 to 800 dolphins, or even measure it will all the uncertainty and variability in our estimates. Fortunately, there are other reliable ways to measure population health.
The method we’re using is to estimate survivorship, which is the probability of an individual surviving from one year to the next. If this number proves to be lower than what we expect from other, healthy dolphin populations, then we need to look at factors affecting survivorship. If the number comes out to be typical of dolphin survivorship, then management actions are not necessary.
We’re off to a tremendous start. Our good friend and neighbour, Alexandra Morton, has been collecting photographs of the dolphins’ unique markings and dorsal fin shapes since the dolphins returned to the area in the late 1980’s. Alexandra’s exhaustive field efforts and meticulous work has produced records that include thousands of dolphins. With this extensive catalogue and my photographic effort over the last 5 years, we now have the opportunity to learn essential information about Pacific white-sided dolphins and their populations.
Using photographs of unique natural markings on the dorsal fin and sometimes body, we create a record of encounters, an ‘encounter history’ that provides information about each time you saw that dolphin. Using mark-recapture statistics, you can estimate how many there are, the likelihood that an adult dolphin will survive from year to year and lots of other neat things. This helps make decisions about whether we need to take action to confer additional protections from human threats.
Imagine it as a trip to the doctor’s office. The doctor weighs you, takes your blood pressure, and maybe takes some samples. Then she compares your “status” to what she’d like to see in a healthy patient. In much the same way, we’re identifying whether dolphins in BC are surviving as long as we’d like to see. If not, then we’ll do some follow-up work to identify why, and whether we can do anything about it. Sure, dolphins are cool. We like them a lot. But we also like the scientific challenge of studying this species. We are only seeing a small fraction of individuals for brief periods at the surface. It’s forcing us to develop new mathematical tools, and spend lots of time in the field, and everything we learn feels new and exciting.
A lot of our time is spent looking for whales and dolphins. When we find them, we assume that the animals are in a particular place for a good reason. The area that the animals occupy is their habitat, and much of our scientific research aims to identify why animals are found in some areas and not others. The aim is to identify the kind of habitat that species prefer, and to conduct science that lends support for legal protection of important habitats for whales, dolphins and porpoise. Sometimes this is as coarse as simply animal mapping distribution from surveys. In really well-studied species like killer whales, our work can get quite narrowly focused.
LOCATION, LOCATION, LOCATION
Imagine a killer whale’s behaviour as providing a Yelp review of restaurants. If a whale is always feeding whenever you see it in a particular spot, then that spot can be thought of as a “restaurant” that gets 5 stars. If a whale is never seen feeding in a particular area, it gets 0 stars. Our study mapped feeding preferences of endangered southern resident killer whales in the waters around the San Juan Islands. [For the locals, it turns out the southside received the 5 star review. Not very surprising, I guess. The area’s called Salmon Bank for a reason.] But the take-home message is that preferred feeding habitats can be targeted to receive priority for habitat protection and considered in marine spatial planning initiatives. Our work has convinced us that despite their wide-ranging and migratory lifestyles, whales, dolphins and porpoises can benefit from marine protected areas.
We’ve found that critical habitat for whales can be a mixed blessing of sorts. Whales may aggregate in certain areas because they are reliable places to find food and mates, but this tendency to aggregate may lend whales surprisingly vulnerable to catastrophic events like oil spill.
If we had our choice, we’d just study marine wildlife on its own terms. Realistically, the animals we study live in an increasingly human-dominated landscape. Human activities influence how loud the ocean is, how much fish is available to support marine mammal populations, and how many whales are killed by ship strikes or how many dolphins and porpoise are entangled in fishing nets.
A lot of the work we do measures behavioural responses of killer whales to boat traffic. You can read about those papers here, here, here and here. If boats disturb whales over and over again, this can affect the whales’ activity budgets, which can carry energetic costs. Ultimately, all the ship traffic – whalewatching boats, container ships, ferries and oil tankers – increse ambient noise levels in important whale habitats. Read more about the issue of chronic ocean noise on our Acoustics page.
