oceansadmin - Oceans Initiative

It’s the whale equivalent of Park Place and Boardwalk…

by oceansadminHabitat November 28, 2010No Comments

killer whale spyhop — Not all ocean habitat is created equal. We study killer whales at extraordinary beaches that whales use for rubbing. For most other populations, we use spatial statistical models to identify areas that whales and dolphins use more often than you'd expect from chance alone.

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.

Human impacts on the ocean

by oceansadminHuman Impacts November 28, 2010No Comments

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.

The whale bone’s connected to the fish bone…

by oceansadminEcosystems November 28, 2010No Comments

Think of all of our projects as cogs in a machine. Ecosystem-based management is the theme that integrates all of our work. Ecosystem-based management is a philosophy entrenched in the Convention on Biological Diversity that acknowledges that elements of an ecosystem are linked. From our perspective, it means that we are trying to estimate abundance of whales and dolphins in part because we want to ensure that fisheries management leaves enough fish in the sea to account for predator needs. It means that we are mapping important habitats for marine mammals because we want to see the data used in ecosystem models that allocate fisheries quotas spatially, again to ensure that fisheries management zones match ecologically relevant scales. This will require great transboundary cooperation. It means that we want fisheries to measure and mitigate marine mammal bycatch. It means that we want to see our acoustic work incorporated into our marine spatial planning work. Ideally, it means that we’d like to see salmon fishing quotas such that killer whale’s caloric needs are more than met – that there is enough salmon left over to leave killer whales resilient to disturbance from human activities.

One fish, two fish, red fish, blue fish

by oceansadminPopulations November 28, 2010No Comments

Counting dolphins — When groups are small and individuals are distinctive, you may be able to count every individual in the group. When populations are big, or individuals are not distinctive, you need to estimate abundance from samples.

Some of the most pressing questions in conservation biology concern the health of populations. “Population” refers to all the animals of a given species that live in the same geographical area and that form an interbreeding community. Should a species be listed under some environmental legislation? Should we allow hunts of healthy populations? Is a species likely to go extinct? These fundamental questions that inspire us rely on having good information about how many animals are in an area, and whether that number is going up or down. We specialise in low-cost and creative methods to provide that information.

But why should anyone care that there are 9,120 harbour porpoise in BC waters?

Well, this number is a crucial piece of information to have if you want to assess whether the population can withstand the level of porpoise bycatch in fishing nets. In some countries, this number takes on legal ramifications — if fishing practices are causing more bycatch than the population can withstand, it will lead to management actions to change fishing practices, reduce bycatch, or reduce fishing pressure altogether in extreme cases.

Still, we know that these numbers seem cold. Jane Goodall’s chimps were named for a reason. Actually, for lots of reasons. We don’t want to know about thousands of whales. People connect to individuals. Moby Dick. Flipper. Shamu. Willy (Keiko). We get it, and we like studying individual whales and dolphins. But a population is just a collection of individuals. We study individuals to understand how populations are doing; and we have done coarse studies that estimate abundance overall, to guide future studies on the health of individuals. The point is: we use a lot of math in our research, but these animals are not just numbers to us.

We have expertise in the two most widely used methods to estimate abundance of marine wildlife: mark-recapture statistics; and line transect surveys. Mark-recapture studies take samples of individually distinctive animals, revisit an area and sample again, and use these samples to make inference about how many animals there must be in the population for us to see the individuals we do. If you can track individuals through time, you can estimate other population parameters than just abundance: you can also estimate survivorship, trends in abundance, reproductive rate, social structure and movement patterns. We have conducted mark-recapture studies on humpback and killer whales, but the focus of our mark-recapture work is on Pacific white-sided dolphins. Read more about the dolphins here:

Line transect surveys don’t require us to know anything about individual identity. Instead, we estimate density of whales (or sharks: check this out). The math is a bit nerdy, but we like it a lot. We’ve contributed to the methods by testing new methods for distance estimation, survey design for geographically complex regions, abundance estimation from cheap platforms of opportunity, and have field-tested methods to estimate abundance of rare species. We’re not mathematicians, but we like working with them on our most challenging studies, like Amazon river dolphins, Antarctic minke whales in the sea ice, or marine mammals in the convoluted fjords of BC’s Great Bear Rainforest. Read more about the field on our colleagues’ page.

Ships are loud

by oceansadminAcoustics, Habitat, Human Impacts November 28, 2010No Comments

Check out what a humpback whale hears as a ship steams around Vancouver Island:

In partnership with acousticians and engineers at Cornell University’s Bioacoustics Research Program, we’ve deployed a number of hydrophones to measure underwater shipping noise in BC. Cornell’s Dimitri Ponirakis produced this amazing animation based on our data to illustrate what a humpback whale hears as a ship steams around Vancouver Island.