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
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
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.
Dolphin Twitter
We don’t know what they’re saying, yet, but it must be important. Click here to hear clicks, calls and dolphin chatter!
Shipping noise and project CONCEAL (Chronic Ocean Noise: Cetacean Ecology and Acoustic habitat Loss)
Sound is as important to whales as vision is to us. Sound travels farther in the ocean than light does — so whales grunt, call or sing, or listen intently, and their lives depend on sending and receiving these acoustic cues reliably. They’re quite good at it. Whales and their prey have evolved these acoustic systems over millennia. The problem is that in the last hundred years or so, we have started competing with whales for acoustic space by using ships and conducting other activities that create a lot of underwater noise (mostly unintentionally). So trying to communicate through underwater noise is a little like having a great cell phone that relies on a terrible network provider. Unfortunately for whales and other marine life, the consequences of a “dropped call” are more serious than they are for us. If human activities jam whale acoustic signals, the information lost is not trivial. We suspect that the acoustic information being transmitted is of the kind: “There is a predator just around the corner.” Or, “Eat this fish. It may be the last one you see for days.”
The cornerstone of our acoustics project uses pop-ups, developed by Cornell University’s Bioacoustics Research Program. These autonomous machines sit on the seabed, recording anything that swims or sails by until they are told to come to the surface. We have been using these machines since 2008 along the continental shelf waters of British Columbia, Canada. With a lot of help from mariners throughout BC, we’ve successfully deployed and retrieved 12 of these fancy rigs in sometimes terrible weather. We now have thousands of hours of recordings of ambient sounds that include whale and dolphin calls. Our future plans include a study to extract these calls to help us identify important habitats within BC for different marine mammal species. But for now, our primary interest is in the shipping noise data on the recordings. Working with Chris Clark at Cornell, we are modelling how much acoustic space the whales lose from different levels of shipping noise.
In conjunction with this study, Rob has recently won a Marie Curie Research Fellowship and is now Principal Investigator on the EU FP7-funded project CONCEAL (Chronic Ocean Noise: Cetacean Ecology and Acoustic habitat Loss) to investigate the effects of acoustic masking on whales. This study builds on Rob’s 2009-10 Canada-US Fulbright Visiting Research Chair position at the University of Washington to compare Canadian and US policies to protect whales from human-caused noise. Project CONCEAL builds linkages between biologists and statisticians at University of St Andrews to model population-level consequences of the acoustic masking work that Rob and his colleagues at Cornell are demonstrating.
