The best of times, the worst of times: Dolphin-palooza 2011; Earth Day; and the First Anniversary of the BP Spill

This is a big week for the planet. Earth Day and the one-year anniversary of  the BP/Deepwater Horizon oil spill in the Gulf of Mexico.  It will take years to assess the damage from the Gulf spill economically, societally and ecologically. A recent paper in Conservation Letters led by Oceans Initiative’s Dr Rob Williams with the help of many co-authors, suggests that the dead dolphins washing up on the beach are really just the tip of the iceberg.   The team evaluated historic carcass recovery rates in two ways.  One indicated that there could be as many as 50 dolphins that were scavenged, drifted offshore or sank to the bottom of the ocean for every dolphin carcass recovered on the beaches. The other method yielded an even scarier ratio of 250:1.

Photo: Associated Free Press

Dead whales and dolphins on beaches represent only the damage we can see. Killer whale biologist and director of the North Gulf Oceanic Society, Craig Matkin, notes that a genetically distinct pod of killer whales, the AT1pod, exposed to oil from the Exxon Valdez oil spill, have yet to reproduce 22 years later. Since no calves have been born, the unique killer whale pod will be lost.  However grim the statistics, scientists are able to make these calculations thanks to years of careful research on whale and dolphin populations.  Closer to home, imagine how warped our perception of killer whale populations in BC and Washington would be if all the information we had available came from the occasional carcass that washes ashore, instead of conducting annual counts of the entire population, which is what our colleagues at Fisheries and Oceans Canada and the Center for Whale Research do.  There is simply no substitute for the hands-on, hard work of long-term monitoring of cetacean populations.

But many cetacean populations are still under the radar.  You may be surprised to find that for many whale and dolphin species, we still lack basic information on how many  there are and how healthy the populations are.  In 2004, we partnered with Raincoast Conservation to design and conduct systematic surveys to estimate abundance of 6 cetacean species in BC, and we’ve seen first-hand that it is possible to contribute important baseline science while working on a modest budget.

At Oceans Initiative, our aim is to identify data gaps and make it a priority to fill the ones we can afford to (and are most qualified) to fill. Earth Day prompts us to reflect on the contribution we are making to marine research and conservation, but our goal, every day, is to identify modest contributions that we can make to improve the quantity and quality of science available to make decisions that sustain the BC marine environment.

Our recent dolphin ‘spring fling’ {AKA Dolphin-Palooza 2011} is a good example.  With 10 days and a lot of help from our friends and neighbours, we collected gigabytes of photo-identification and acoustic data on Pacific white-sided dolphins in BC, at the extreme south end of the Great Bear Rainforest. Because we are building on Alexandra Morton’s 20 years’ worth of meticulous photographs and observations, we expect that soon we will have a good estimate of abundance, survival and a glimpse into Pacific white-sided dolphin population structure. These important pieces of information form the basis on which sound management decisions can be made. The kind of baseline information we are collecting is essential, whether we are dealing with day-to-day conservation and management decisions or (heaven forbid) assessing damage and supporting recovery if a catastrophe on the scale of the BP oil spill should ever occur in Pacific Northwest waters. The science we do is not the most glamourous kind of field work, but it is necessary.  And we love what we do.

Pacific white-sided dolphins leaping in Knight Inlet, British Columbia

Things that go bump in the night

A killer whale surfs the bow wave a cruise ship in Johnstone Strait.

When ships strike whales, the whale generally loses. People must wonder why scientists treat this issue like it’s some great mystery that’s difficult to quantify and even more difficult to solve.  After all, hitting a large whale must be like hitting a moose with your car.  Right?  So fixing the problem must be as easy as searching the shipping lanes for marine roadkill, and making shippers slow down.

This Pacific white-sided dolphin has a huge gouge near its tail flukes. Was it caused by fishing gear, a propeller, or something else?

In fact, assessing the extent of ship strike mortality is incredibly challenging.  Sure, vessel operators may underreport whale strikes, but in fairness, with very large, fast ships, collisions may go entirely unnoticed.  A typical cruise ship may weigh 50,000 tonnes.  A typical fin whale may weigh 50 tonnes.  Yes, that’s a lot of whale, but it could be analogous to hitting a 2kg animal with a 2,000 kg SUV.  Except that the ship strike can happen in a lurching, heaving sea, with the ship moving and whale surfacing and diving in three dimensions.  And when whales die, whether from human or natural causes, only a trivial fraction of carcasses are recovered. To us, it’s a wonder that this issue is reported as frequently as it is, given all the odds against detecting the problem in the first place.

Fortunately for the whales, this issue is receiving a lot of scientific and management attention.  Off the east coast of the US, scientists have built a convincing case that the critically endangered North Atlantic right whale population cannot withstand the death of even one individual annually from ship strikes, so tremendous bilateral efforts have been made to separate ships from whales in important habitats in both the US and Canada.  Recently, regulators have started issuing speeding tickets for mariners who violate the rules designed to protect the whales.

In 2010, we partnered with Dr Patrick O’Hara (Environment Canada) to conduct a risk assessment to identify where ship strikes may be an issue for fin, humpback and killer whales in BC.  A risk assessment involves two main components:  (a) trying to estimate the likelihood of a thing (usually bad) occurring; and (b) predicting the consequences if it does.  Put simply, we mapped where ships and whales are likely to overlap.

This overlap analysis actually tells us three things:

1. oil spill risk:  Shipping intensity seems like a good proxy to use for oil spill risk.  The probability of an oil spill happening is low, but if it happens, it can be catastrophic to individuals and populations.

2. ship strike:  again, the probability of it happening is low, but it can be fatal.  And if it happens often enough, it can be damaging to populations.  Our work is showing that fin whales in BC cannot tolerate the removal of more than a few individuals per year.  Given the occasional, high-profile examples of ship strikes involving fin whales worldwide, we wonder how much of an underestimate these reports represent.

Predicted areas of overlap between shipping activity and humpback whales in BC (from Williams & O'Hara 2010).

3. chronic ocean noise:  high noise levels are a sure thing in a shipping lane, and we’re just beginning to quantify the effects on marine mammal habitats, individuals and populations.  Our colleagues are documenting similar effects of noise on non-mammalian wildlife like squid and fish.  So, we believe that even if a ship doesn’t strike a whale, this “overlap analysis” can still tell us where important whale habitats are likely to be degraded by chronic ocean noise.  Our work has shown that repeated disturbance by boats can disrupt the feeding behaviour of killer whales, and our new research (with Cornell University’s Bioacoustics Research Program and the Sea Mammal Research Unit at the University of St Andrews) is modelling how much acoustic space whales lose from shipping noise.

Thinking big. Establishing general principles from little truths: lessons from marine mammal research

Harbour seals in the forest

When most people think of scientists doing research on animals, we think of geeks in lab coats, experimenting on lab rats.  Guinea pigs.  Fruit flies.  Maybe a guppy.  Actually, marine mammals make fascinating study animals, but their aquatic lifestyle and large body size pose challenges to studying them in the wild — you try to train a blue whale to swim through a maze.  Journal of Zoology has been publishing research on the biology of animals in one form or another since 1832.  Rob serves on their editorial board, and was recently invited to write an editorial explaining why marine mammals pose tremendous challenges and opportunities to studying and protecting wildlife.

(See excerpt below, but the complete editorial is available to subscribers.)

Rob’s point is that we need to establish big-picture models of how systems work, because humans are altering the environment everywhere, quickly, and we will never have time or resources to test every possible combination of species, place and impact.  Nor should we always insist on case-specific evidence.  We should be careful before experimenting on critically endangered species, for example.  It is precautionary to use the best available science to predict how species are likely to respond to human activities.  After all, once a chemical has been shown to be toxic to a given species, we don’t insist on testing it on every other species in the animal kingdom.  Closer to home, this may mean that when it comes to protecting at-risk populations like southern resident killer whales, we should adopt what Dr Peter Ross calls a “weight of evidence approach” to decision-making.  We trust that contaminants may be impacting the whales, because excellent studies on harbour seals have shown that the contaminant levels we’re seeing in killer whales can impair reproductive function.

ESTABLISHING GENERAL PRINCIPLES FROM LITTLE TRUTHS

“Ken Norris, one of the pioneers of marine mammal science, once wrote that marine mammalogists were tasked with compiling ‘little truths on which future understandings . . . may be anchored’ (Pryor & Norris, 1991). This modest set of expectations reflects the fact that marine mammals are difficult to study because of their lifestyle; our studies are often based on infrequent glimpses of animals at the surface.  …  But it is often the case that decisions must be made in the absence of good, species-specific and context-specific information. Comparative approaches are one way of interpolating across species to predict vulnerabilities generally: these comparative approaches could be as ambitious as drawing parallels between the social structure of elephants and sperm whales. The better we understand the basic patterns of form and function in zoology, then more powerful and predictive this comparative approach becomes.

Fundamental information is needed about key animal species that can be gleaned from direct study or through comparative approaches to help us address conservation questions now and in the future. We need to establish general principles in zoology that can allow us to tackle issues as quickly as they arise. If we need to study every problem as if it were a new issue from first principles, then we will always be behind the curve and never be much use at giving advice to managers, sociologists, economists, planners and politicians.”

So.  What do you think?  Where should we place the burden of proof? We use contaminant studies on harbour seals as proxies for killer whales when we decide that we need to clean up Puget Sound if we want to protect killer whales.  What about noise impacts?  What about predicting the effects of declining salmon stocks on killer whales?  What about predicting the likely impacts of alternative energy projects on endangered species?  How much direct evidence do we need to inform decision-making about endangered species?  When is the “best available science” enough, and when is it not enough?  How do we decide when more science is needed, versus acting on the information we have available?

From:  Williams, R.  2011.  Establishing general principles from little truths: lessons from marine mammal research.  © Journal of Zoology 283, 1-2.

Human impacts on the ocean

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.

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.

Humpback whales rely on sound: they make coordinated feeding calls when bubble-net feeding, and their songs on the mating and calving grounds are among the most complex in the animal kingdom.