Southern Resident killer whale monitoring on San Juan Island

October 13, 2018

This summer, from mid-July to the end of September, we studied southern resident killer whale behavior under varying levels of boat and ship traffic. (This is an extension of our 2017 field season with OrcaSound). The Port of Vancouver has asked ships to slow down to less than 11 knots as they transit Haro Strait. Reducing ship speed can reduce shipping noise underwater, but slower speeds mean those ships take longer to transit the area. Working with Port of Vancouver and SMRU Consulting, we are exploring how whales navigate that trade-off between noise level and duration of exposure.

Do the whales find more salmon if they are exposed to a little bit of noise for long periods of time? Or is it better to get the noise over with quickly? 

Reducing noise is especially important because endangered southern resident killer whales (SRKW) feed in Haro Strait in the summer, and our work has shown that vessel noise disrupts killer whale foraging. While missing one meal might not seem like it would have long-lasting or population-level effects, Haro Strait is a noisy place, which may result cumulatively in many lost meals for the killer whales. We had our team on the western hillsides of San Juan Island all summer to track killer whales in an effort to find out if and how their behavior changes with the slower, quieter ships.

A ship transits Haro Strait by a family of southern resident killer whales. (PC Toby Hall). The theodolite crosshairs allow us to convert horizontal and vertical angles to estimates of latitude and longitude, knowing the cliff height.

To track these whales, we used an instrument called a theodolite. You may have seen them on construction sites or traffic surveys. A theodolite has a telescopic lens that we use to track killer whale movement. After setting a constant reference point, the theodolite can determine the angle between the reference point and the whale we’re looking at. It gets the vertical angle from a gravity-referenced level vector. A computer connected to the theodolite can use those two angles (along with the precise location and elevation of the theodolite) to estimate distances and fixed positions of objects on the ocean’s surface (whales, ships, etc). Your geometry teacher was right—this math does have real-world applications. And we can get all of this fine-scale information noninvasively, without another research boat confounding the effect we are trying to measure. This year, the developer of Pythagoras software generously shared code to let us integrate extremely high-resolution AIS data on the movement of ships, so we could automagically collect precise and accurate data on the ships, while having our expert observers concentrate on measuring the whales’ behavior.

In 2017, the killer whales were worryingly absent from the islands much of the summer, which left us with a small sample size. In fact, for the month of August 2017, the SRKWs were nowhere to be found. This year’s longer field season produced much more data. There were 29 days with whales present around San Juan Island. We had tracking stations set up in three locations along the west side of San Juan Island: County Park, Hannah Heights, and Cattle Point, which allowed us to get close to continuous tracks along Haro Strait. We are excited to analyze the data, which should allow us to determine more about killer whale behavior in the presence of these slower ships.

Video credit: Toby Hall

This work felt profoundly important this year, in a season riddled with heartbreaking news about the endangered southern residents. J35’s calf died shortly after being born, and the mother mourned the loss of her offspring by pushing around the carcass for 17 days. J50, the youngest individual in the southern resident population, was found to be critically malnourished. NOAA launched the first attempt to supplement a southern resident killer whale’s diet with additional fish. Unfortunately she has not been seen since September 7 and is presumed dead. It is abundantly clear than additional conservation effort is needed, and our team worked hard to make this field season count, both in the field and on the Southern Resident Killer Whale Task Force.

This work wouldn’t have been possible without a super pod of a team. The Oceans Initiative team was led by Erin and Rob, and consisted of our employees Laurel Yruretagoyena, Natalie Mastick, and Laura Bogaard, as well as Toby Hall, Sarah Colosimo, Jess and Chris Newley, and Elizabeth Robinson, who provided additional field support.

Thank you, as always, for supporting our efforts to keep orca habitat clean, quiet, and full of salmon.

Please help us keep orca habitats clean, quiet, and full of fish

September 20, 2018

 

 

The critically endangered southern resident killer whale population now numbers 74 individuals. The ability of the population to recover is hindered by a perfect storm of threatsnot enough salmon, too much noise, and toxic chemicals affecting calf survival—but lack of access to salmon is at the eye of that storm.

We need to recover Chinook salmon stocks throughout the whales’ range. 

We support all efforts to do so. We support dam removal, where this will get more salmon into the environment. We applaud the recent announcement to reduce salmon fishing quotas until the whales recovery, which will reduce our competition with the whales. While we wait for those measures to take effect, we need your help to give the whales a fighting chance to find as many of those salmon as possible in a noisy ocean.

We need to give the whales a quiet place to hunt for salmon

Our work has shown that killer whales spend 18-25% less time feeding on salmon when boats are around than when they are undisturbed. We have found that the southern resident killer whale population needs 662 big, fat Chinook salmon each day. We have found that mothers with calves need 43% more calories, more salmon, than adult females without calves.

A protected area can help the whales if we put it in the right place. 

We have found that killer whales are more vulnerable to disturbance when they are feeding than when they are travelling from A to B. They also need more salmon. We have identified areas that whales use preferentially for feeding. (One is called Salmon Bank. We have a feeling the whales knew this before people did.) We need to bring together all dedicated datasets we can use to identify areas where the whales are finding salmon, so we can prioritize those for protection. Protecting key feeding areas is essential to protecting the whales.

Please support our efforts to keep orca habitat clean, quiet, and full of fat, wild salmon.

PS Thanks to our team, especially Toby Hall, for the great footage, and to our friends at SeaLegacy for help editing this video.

Our Vision for Recovering Killer Whales: A Clean, Quiet Ocean Full of Salmon

August 22, 2018
Southern resident killer whales in Haro Strait. Photo by Toby Hall

Southern resident killer whales in Haro Strait. Photo by Toby Hall

Southern resident killer whales are in decline.  Our recent population viability analysis on southern resident killer whales predicted that, if threats remained constant, it should take several decades for the population to decline from 80 to 75 whales. In fact, that decline took only three years. We fear that the decline is accelerating, and we may be reaching a tipping point.

By studying killer whales from land, we can measure their responses to noise without adding the noise of a research boat to the equation. We use noninvasive techniques to measure swimming speeds, breathing rates, and other behavior. Our work on both northern and southern resident orca has shown us that the whales spend 18-25% less time feeding in the presence of boats than in their absence.

We recently joined an international, interdisciplinary study to understand the relative importance of the three main threats to recovery in the endangered killer whale population. The whales are facing a perfect storm of threats–not enough salmon, too much noise, and too many toxic chemicals in their bodies–but lack of prey is at the eye of the storm. This research shows it will take 30% more big, fatty, Chinook salmon than we’ve seen on average over the last 40 years for the population to reach our recovery goals. That will take time, but we have to start now. Meanwhile, reducing noise and disturbance can help make it a little bit easier for whales to find the salmon we have now. In the coming months, we will be revisiting our study on identifying critical foraging areas in the Salish Sea and strengthening their protection.

One fish, two fish

August 11, 2017
Our Animal Counting Toolkit offers open-access data and tools to guide low-cost, small-boat surveys for marine wildlife

Our Animal Counting Toolkit offers open-access data and tools to guide low-cost, small-boat surveys for marine wildlife

Knowing how many animals are in a population is at the cornerstone of many conservation and management decisions. For whales, dolphins & porpoises, ship time to estimate abundance can be prohibitively expensive — often running into the tens of thousands of dollars each day.

We’ve just launched our Animal Counting Toolkit to share some of the lessons we’ve learned over the years in conducting low-cost, small boat surveys for marine mammals in coastal waters. It was a lot of fun to publish this work with our colleagues at University of St Andrews, NOAA, IUCN, CyberTracker, BlueWater GIS, and other NGOs and consulting companies. This is a gentle introduction to designing and conducting a survey to estimate abundance of marine wildlife. It is not a substitute for statistical training, but it should provide a good background for data collection. For data analysis, we strongly recommend joining the Distance Sampling web community and taking the Distance workshops at University of St Andrews

We published an open access paper introducing our Animal Counting Toolkit approach. Wherever possible, the approach prioritizes free software and tools. Our audience is the community of marine naturalists and scientists who may need a bit of guidance to ensure that their observations could be turned into a useful biodiversity monitoring program. We hope the Toolkit finds an audience among NGOs, grad students, coastal communities, and researchers working in countries where funding is severely limited. The US just passed a rule requiring countries to demonstrate that their fisheries are sustainable in terms of marine mammal bycatch. This rule affects $20 billion/year in seafood trade. It is driven in part by a need to level the playing field for US fisheries that have to comply with the Marine Mammal Protection Act and are competing with fisheries that are not MMPA-compliant. Used wisely, the new trade rule will use the purchasing power of the US market to create incentives to improve fisheries sustainability and transparency. But if it is imposed too harshly, and without funding for low-income countries to comply, the US risks penalizing countries that can least afford to take an economic hit. Our Animal Counting Toolkit was motivated in part by this new rule. We want to fill in important data gaps around the world, but we also see value in using this toolkit to help build local and regional capacity for countries to begin to do the kind of surveys that will be needed to demonstrate compliance with this new seafood trade rule. Our hope is to see countries actually improve sustainability of their fisheries, so that we reduce the number of marine mammals killed in fisheries while improving economic opportunities for people who earn their living from the sea.

Telling stories about wildlife populations, one photograph at a time

July 09, 2017

Guest post from our newest team member, Natalie Mastick

“I look at pictures of dolphins all day,” is my most common answer when asked what I do for work.

 

This dolphin has a well-marked dorsal fin, which we will match against thousands of photographs in our database. This photo was taken under research permit with a telephoto lens and cropped.

This dolphin has a well-marked dorsal fin, which we will match against thousands of photographs in our database. This photo was taken under research permit with a telephoto lens and cropped.

It’s an over-simplified statement, albeit accurate, and it usually leads to many follow-up questions. The most frequent being “Why?” That’s a fair question. I then proceed to explain how by looking at photos of the dorsal fins of dolphins, I can identify individuals, which can be used in calculating population estimates and survival rates. I am usually surprised by the awe that this explanation inspires, as I am somewhat numb to the task after several months of photo analysis. “You can really tell dolphins apart like that?” They have a point; photo-identification is quite remarkable when you think about it.

Photo-identification (photo-ID for short) is a non-invasive way to study marine mammal populations. It’s been used for both cetaceans (dolphins and whales) and pinnipeds (seals and sea lions), and requires a high-resolution photo of each individual. Photo-ID is an effective way to determine individuals based on coloration, markings, scars, fin shape, nicks and notches. For humpback whales, the underside of the fluke is the most recognizable feature, which is can be photographed as the whale dives. For dolphins, one of the most recognizable features is an individual’s dorsal fin, visible as the dolphin breathes at the surface.

I have worked on several projects that use photo-ID, including a long-term study of bottlenose dolphins in Florida, humpback whale population analysis in Antarctica, and currently, a long-term study of Pacific white-sided dolphins in British Columbia with Oceans Initiative. To accomplish this work takes three major steps: photographing wild dolphins, processing the photos, and then looking for matches between the photos.

Oceans Initiative has been taking photos of these dolphins since 2007, which is not an easy feat. Pacific white-sided dolphin are fast and can often travel in large pods of hundreds of animals. Erin, Rob, and their dedicated field team have a ton of experience taking photos of these animals, which provided me with a hearty collection of over 10,000 photos to process. One by one, I went through and determined the quality of each photo. Obviously when photographing hundreds of dolphins quickly surfacing and diving, not every photo will be useable for a photo-ID catalog. I found the photos in which fins were in focus, parallel with the camera, and mostly visible (not partly submerged or covered by water or other dolphins) and then looked carefully at each fin to determine its distinctiveness.

It never ceases to amaze me how different dolphin fins can look. A dolphin can have a single little notch at the base of its fin that makes it completely distinct from the rest of the dolphins seen that day. The combination of scarring, nicks from other dolphins, entanglements, killer whales, and normal wear and tear provide an endless permutation of unique fins. I visually assessed each high-quality photo and determined if the fin was not distinctive, somewhat distinctive by temporary marking or discoloration, moderately distinctive, or highly distinctive. Moderately and highly distinctive fins can be used to identify an individual over longer temporal scales.

Once the fins were scored for distinctiveness, it was then my job to match them to other fins within that encounter, and lastly between encounters from that season. When matching between a single encounter, it’s a lot like a game of memory. You know you’ve seen that fin before, you just need to remember where in order to match them. Once the fins are matched within an encounter, I compile a “best of” folder with all of the identifiable individuals observed in that area to match to the other encounters.

When you include the variable of time, then it becomes more like a game of 6 differences, in which you need to spot what’s changed in a fin over time. Except instead of having two fins that you know are just slightly different versions of the same fin that you’re comparing side-by-side, you need to look through the entire catalog to determine if a fin has actually changed since last identified or if it’s a new individual. Though that’s a fun challenge, it is unlikely that a fin changes much over the course of a few weeks, which means matching fins across encounters is a little easier than across years.

To match fins across encounters, I compile all of the moderately and highly distinctive fins from each encounter and look for individuals seen more than once. The 2016 field season provided over 1000 identifiable photos, which were then compared to each other to determine if there were matches. This is where your imagination comes into play. Looking at these fins enough, you start to see shapes in the nicks and notches and fin shape. There was a fin with a distinctive nick towards the top that looked like the profile of a person yelling. There was another that looked remarkably like a bicep. There was one photo in which a fin caught the light just right and looked like it was reflecting back the shape of a storm trooper.

Reading that back sounds like I’ve kind of lost it. Looking at fins enough might do that to you! But overall, being able to put a minimum number to the dolphins seen last season (think about all the dolphins we couldn’t photograph and the fins that weren’t distinctive enough to match!) is incredibly rewarding, and completing each step of the processing myself was oddly satisfying. I’m hoping we can get a comparable number of photos in 2017, and look forward to seeing some familiar fins in the field.

Natalie Mastick

Teamwork

June 05, 2017
A family of orca (killer whales) works together to find food off northern Vancouver Island. (Photo taken under research permit, zoomed and cropped.)

A family of orca (killer whales) works together to find food off northern Vancouver Island. (Photo taken under research permit, zoomed and cropped.)

 

One of the things we admire most about orca or killer whale cultures is their commitment to teamwork. They work together to find food, coordinate travel, and thrive in a cold, dark environment where prey are easier to find using sound than light. These whales serve as a great template for people working together to tackle some of the world’s most pressing environmental problems, including unsustainable fishing, climate change, and ocean noise. These are challenging times.

As we enter World Oceans Week, we are inspired by the team at Sea Legacy, including the amazing conservation photographers, Cristina Mittermeier and Paul Nicklen. In words and in deed, they show that we can accomplish more #together than we can as separate voices. Taking a cue from Paul and Cristina, we’d like to offer the Oceans Initiative team three ways to help during Oceans Week.

  1. Spread the word. We do “use-inspired science” to guide effective conservation of marine wildlife. By definition, you are a key part of the research questions we ask, and what we do with the information we produce. We can’t do this without you. We’d love to hear from you. Please comment on this blog, or share it with your friends. Sign up for our newsletter. We never share lists, and we won’t fill up your inbox. Encourage your friends to like us on Facebook, and actually click the “follow” button to see what we post. We’d love to hear from you on Facebook, because the platform lends itself to back and forth conversations. Our Twitter feed is interactive, and light, but focuses on emerging science on marine conservation and solutions. We have a large and growing audience on Instagram, and we’d love to see you there. These sound like trivial things, but they matter. Many funders use social media metrics as an indicator of a nonprofit’s reach. Please help us spread the word about our work.
  2. Donate frequent flyer miles. Aeroplan, Air Canada‘s frequent flyer program, is matching all donations of Aeroplan miles 1:1, up to 500,000 miles, this week. Your donated miles help in many ways. The flights get our team to the field, bring top scientists and aspiring young biologists to join us, let us bring our skills to other countries to help build capacity in lower-income countries, and ultimately, to take the information to the meetings where important conservation decisions are made. Aeroplan even offsets the carbon footprint for every flight we redeem through this special program.
  3. Invest in our work. As much as we try to do more with less and be good stewards of charitable dollars, it still takes money to do the conservation work we do. Every dollar made to our partner charity in Canada enters us in a draw to win $10,000 from CanadaHelps. Every dollar is directed to the dolphin conservation project in British Columbia. American taxpayers can receive a tax receipt for any donation made through our website.

Thank you so much for your help. We are starting to see some real-world conservation successes emerging from our work on ocean noise and marine mammal bycatch in fisheries. Thank you for allowing us to do that work.

Happy Earth Day!

April 22, 2017

leapingdolphin

Today, 22 April 2017, marks the 48th time that people around the world celebrate Earth Day. Since 1970, the effects of climate change have become undeniable, but the environmental news is not all bad. The voices of 1970s environmental grassroots movement were heard, and that public pressure led the USA to pass some of the most powerful legislation anywhere to protect endangered species and their habitat. Given our focus, it’s not surprising that we see the Marine Mammal Protection Act as one of the best examples of grassroots movements leading to real-world conservation gains. Over the last few decades, consumer demand has shifted fisheries practices to the extent that “dolphin-safe tuna” is now the industry standard in North America and Europe. Similar efforts drove the Save the Whales movement, which led to a moratorium on commercial whaling in 1986. We’re not naive, but we are inspired by #OceanOptimism.

After every public lecture we give, people ask how they can help.

People often share feelings of hopelessness and powerlessness in the face of global losses of biodiversity and wilderness. The paradox is that collectively, we hold the power to influence policy, and with every purchase we make, we have the power to influence markets and industrial practices. We cast a vote every time we buy – or choose not to buy – a product. And we are struck by the energy in today’s March For Science events around the world. The people have spoken, and they want policy to be based on reliable evidence. Our tagline, Science for the Sea, tells you that we share that view.

Here are some examples of the power of consumer choice that have inspired us lately. This is not an exhaustive list, and it draws heavily from personal experience. When have you “voted” or made a sustainable choice with your dollar? We’d love to hear from you in the comments.

What are we missing? Please share your Earth Day tips with us.

Notes from the field: guest post from Laura Bogaard

September 25, 2016
Humpback whale flukes with killer whale rake marks (PC: Laura Bogaard, for Oceans Initiative)

Humpback whale flukes with killer whale rake marks (PC: Laura Bogaard, for Oceans Initiative)

It was another beautiful day in the North Island neighborhood and Team Dolphin was all aboard our trusty research vessel, Wishart. We were cruising up Tribune Channel in search of our study animal, the Pacific white-sided dolphin (Lagenorhynchus obliquidens). The water was a magnificent pale blue—a reflection of the late-summer sky, and an indicator that this channel was once the path of an enormous glacier, which carved out the intricate valleys that make up the channels and inlets of the Broughton Archipelago.

All eyes were squinted against the glare as we scanned the waves for fins or splashes—any indication that there were dolphins in our midst. Off in the distance, three tall columnar blows gave away the position of a group of three humpback whales (Megaptera novaeangliae) making their way down the channel in our direction. We decided to slow our course in order to snap a few ID shots. We waited a few minutes for another surfacing and then, as if on cue, three more blows erupted through the surface almost in unison. One right after the other, each whale turned and dove deep into the blue water, flipping their tails and exposing their flukes as they descended. Armed with rapid reflexes and two spectacular cameras, Rob and I were able to grab ID shots for each whale in the short window of time that their flukes were vertical and above the water.

This is a photo I took from that encounter. The dark parallel lines you see are killer whale (Orcinus orca) rake marks that this whale probably sustained during a run-in with a transient orca. The scars left behind will help lead to an individual identification of this particular whale. Even after seeing them almost everyday this month, the size and agility of these creatures still astounds me.

The humpback’s smaller and speedier cetacean cousins, the Pacific white-sided dolphins, had the spotlight this season for Erin and Rob’s research project. They were quite a bit trickier to photograph than the humpback whales because of their speed and unpredictable behavior. After a month of working with them almost every day and shooting thousands of photos, I feel like I am finally getting the hang of it. Photographing wildlife can be a challenging experience, but with the right amount of patience, persistence, and positivity, the results are incredibly rewarding.

My favorite job on the boat was operating the hydrophone. Like photography, there was a bit of a learning curve. It took quite a few tries to get the hang of wrangling the long wire and recording in time to catch some vocalizations. Sometimes the dolphins would suddenly change their behavior and squall away at high speeds out of the detection range. Sometimes they were just silent. However sometimes, once the engine was off, the hydrophone was in the water, and the recorder and amplifier were switched on (given the batteries were charged and the SD card was in its slot), the voices that came through my headphones were simply breathtaking. This piece of equipment allowed me to access an underwater world that few people are lucky enough to experience. Listening to their whistles and calls as they communicated with each other and to their buzzes and clicks as they echolocated in search of food, added a whole new dimension to observing their behavior at the surface. It gave me a new appreciation for their complex sociality as well as the impact that ocean noise must have on their daily lives.

This is just a taste of a few of the wonderful experiences I have had this month during my Experiential Learning internship working with Oceans Initiative. I’m sad to leave the dolphins behind as this season comes to a close, but I am looking forward to working with Rob and Erin more this winter to help analyze the acoustic data we have been collecting over the last month for my Keystone thesis project at Quest University.

I have learned so much about the many different aspects that are involved in researching cetaceans. I can’t thank Erin, Rob, and Doug enough for being patient mentors and for making my dream come true by bringing me along to Malcolm Island for their field season. Thank you to Clara for the giggles, the sing-along-life-lessons, and for being such a trooper. Thank you MaryAnn for your generosity, warmth, and fabulous suppers. And finally, thank you to the unsinkable Molly Brown Dog for the slobbery kisses, being the best team mascot, and for always being there to keep my hands warm on the boat.

 

Laura Bogaard

September 24, 2016

 

 

Laura deploying a CPOD -- a high-frequency recorder that detects the echolocation clicks of killer whales, dolphins and porpoise.

Laura deploying a CPOD — a high-frequency recorder that detects the echolocation clicks of killer whales, dolphins and porpoise.

Molly Brown

Molly Brown Dog being helpful

Doug searching for dolphins

Doug searching for dolphins

The dolphin days of summer

August 27, 2016

Our team has arrived in the Broughton Archipelago and we are poised to carry out our dolphin photo-ID, health assessment, and disturbance studies. This year, we are thrilled to have an amazing team Laura Bogaard and Doug Sandilands. Laura, a student from Quest University, is our newest research assistant. Doug Sandilands has been working with the incredible team at The Center for Coastal Studies in Cape Cod as part of their large whale disentanglement program. As you all know, Doug is one of a kind and we are so happy to have his help.

Our dolphin health and conservation status project monitors health of individual Pacific white-sided dolphins and their population(s) in the Pacific Northwest. Thanks to Alexandra Morton’s pioneering work on this species, we now have a combined >25 years of data. This project is yielding new insights into the biology of the dolphins themselves, and ultimately about the health of the Salish and Great Bear Seas. In 2015, we launched a health study in partnership with Dr. Stephen Raverty to collect dolphin breath samples on petri dishes to screen for pathogens. This year, we plan to look for drug-resistant bacteria (e.g., linked to agricultural and sewage runoff) and how pathogen exposure changes in urban versus wild marine environments.

A second aim of our work this year is to assess the impact of human disturbance on dolphin behavio(u)r and populations. This non-invasive study will merge our past work on the impacts of vessels, noise, and other sources of disturbance (e.g., on resident killer whales) and the long-term demographic study to understand the population consequences of disturbance. We are not playing noise to the dolphins, but we will use their responses to our own boat and to large ships to explore how much harder dolphins may have to work to find food in a quiet versus noisy habitat.

Our first day on the water was a huge success. We encountered a few hundred Pacific white-sided dolphins foraging in a beautifully coordinated group. Many of the dolphins were well-marked, about 10% of the group were moms with babies, and the dolphins were vocalizing to one another in addition to echolocating. Please check out our Instagram account for more photos.

We look forward to sharing our notes and observations. Thank you to everyone for your support with launching these projects! Please sign up for our newsletter (see sidebar) if you’d like updates when we start generating results from our hard-won field data.

This dolphin has a well-marked dorsal fin, which we will match against thousands of photographs in our database. This photo was taken under research permit with a telephoto lens and cropped.

This dolphin has a well-marked dorsal fin, which we will match against thousands of photographs in our database. This photo was taken under research permit with a telephoto lens and cropped.

Which raindrop caused the flood?

April 30, 2016

KW_seiner RWA lot of the research our charity, Oceans Initiative, conducts is to see how human activities — all of them — affect marine wildlife, both in the Pacific Northwest and around the world. The iconic orca we study illustrate this problem well. According to the latest census by Center for Whale Research, the population is hovering at 84 individuals. The original problem was a live capture fishery for display in aquaria, with all the direct and collateral damage that entailed. But why aren’t they recovering, nearly 40 years after the captures stopped? Regulatory agencies in Canada and the US agree:  it’s a combination of lack of prey (Chinook salmon), too much noise, and chemical pollution.  Some of these threats are much easier to manage in the real world than others. But are we focusing on the right threats?

In our field, this thorny problem is described as “cumulative impacts of multiple anthropogenic stressors.” Clumsy, right? Our colleague, Dr David Bain, described it better:  Which raindrop caused the flood? 

It’s really, really hard to predict how wildlife populations will respond to a minefield of too much ocean noise, not enough food and a body full of chemicals. Think about that for a moment. The blubber that whales put on to survive — used by mothers to make milk for their young — is full of toxic chemicals, and the best way for a whale to detox is to transfer those pollutants to their offspring. Not great for the calf. Adult males don’t even have that option. And if you’re honest about the uncertainty in all the steps and how they fit together, your predictions span the entire range from no effect to catastrophic effects.

Our newest research proposes a way around it.  Start at the end.  Start by asking how much impact on endangered whale populations that our laws allow, and work backwards to calculate how much perturbation (noise, competition with fisheries) it would take to get there.

This approach doesn’t solve the problem, but it helps identify the problem, and the math is easier. For some critically endangered species, policy-makers may not want to allow ANY impact on a population. For healthy, growing populations, our laws allow some impact on marine mammal populations, because humans use the ocean too: for fishing, shipping, recreation, tourism and extracting energy. Our approach gives us a rough, ballpark estimate of what a healthy population can withstand.  Then, you can convene a group of scientists, managers and stakeholders to ask how likely it is that the sum total of all current and proposed activities could cause us to be exceeding that threshold.

There are a number of places around the world where this sort of exercise is needed.  As we try to ensure whale and dolphin populations recover from the Deepwater Horizon incident, it would be good to look at the cumulative effects of all activities, including seismic surveys, in the Gulf of Mexico. As we discuss opening new parts of the Arctic to oil and gas activities and shipping, we can use this method to test whether all of those activities, together, could affect food security of communities living in the Arctic. As we consider the number of industrial developments for the British Columbia coast — ports, liquefied natural gas terminals, pipelines and tanker traffic proposals — it may be time to consider how all of these factor may affect whale and dolphin populations. Some are doing fine. Others are barely hanging on. Our new tool can give us a starting point for discussion how much is too much.

We loved writing this paper with Dr Christopher Clark (an acoustician at Cornell University), Dr Len Thomas (a statistician at the University of St Andrews), and Prof Philip Hammond (a marine mammal population ecologist at the University of St Andrews).  Please check out the #openaccess paper on the website of the journal, Marine Policy:

Gauging allowable harm limits to cumulative, sub-lethal effects of human activities on wildlife: A case-study approach using two whale populations