Preventing extinction of southern resident killer whales, one whale at a time

by Dr. Rob Williams, Chief ScientistConservation, Killer Whale Conservation, Whales, Wildlife HealthPosted on No Comments

Last month, our co-founder and Chief Scientist, Dr. Rob Williams, presented preliminary findings to Washington state’s Puget Sound Partnership Science Panel on our efforts to update what we know about the threats (lack of salmon, ocean noise, and toxic pollution) to southern resident killer whale (SRKW) recovery, to put those threats in the same mathematical currency, and to run different scenarios to see what it would take to prevent the extinction of this iconic population. Sadly, the answer was disheartening and underscored the seriousness of this issue.

When we led a similar effort in 2017, we concluded we could save SRKWs from extinction if we could all work together to get the orcas 30% more salmon. Back then, that seemed unattainable, but our scientific models showed we could recover SRKWs if we increased the number of Chinook salmon in the sea by 15% while doubling the whales’ hunting success by reducing noise from boats and ships. We knew in 2017 that our model relied on science that was already a few years out of date. Since 2017, the whales have been declining faster than our models predicted. We set out to find out why and what we could do about it.

 © Center for Whale Research

Forecasting what it will take to prevent extinction

In 2021, many of you gave generously to help us work with Drs Ben Nelson and Eric Ward to update the part of our model that tells us how SRKW birth and death rates change in good and bad salmon years. With support from Puget Sound Partnership (PSP), we integrated those relationships in a new cumulative effects model and ran management scenarios to see what it would take to reverse the decline. With PSP funding, we expanded our models to include more and better information on contaminants, disease, parasites, inbreeding, and the occasional case of direct, human-caused mortality from vessel strike, etc.

We also turned our direction from hindcasting what got the whales in this mess over the last 40 years, to forecasting what it will take to allow these whales to persist in a warming climate. We found that even our most optimistic salmon recovery targets from 2017 will not be enough to prevent the extinction of this iconic population. We need to slow the decline, buy some more time, and try to prevent sick whales from dying. And it looks as though we have one killer whale generation—28 years—to turn things around before the population tips over into an accelerating decline toward extinction. Inbreeding and climate change make this difficult task even more vexing.

Collectively, we’ve made progress on the noise front. Ship slow-downs by Ports of Vancouver, Seattle, and Tacoma are resulting in less ship noise, and our work is proving that the whales are feeding more when we make less noise in the Salish Sea. Keeping smaller boats farther from whales, and fully protecting foraging hotspots, is helping. In our own organization, we have scaled up the use of innovative, non-lethal deterrents to reduce seal predation on salmon at human-built bottlenecks, such as dams, fish ladders, and the Hood Canal Bridge. All of these efforts are helping but they are not enough to turn the population’s decline into recovery.

SRKW behavioral health metrics program

This year, inspired by our new understanding of the challenge we face saving SRKWs, we started a new SRKW behavioral health metrics program in partnership with Dr. Joe Gaydos, scientist director at the SeaDoc Society.

Dr. Rob Williams, left, with Dr. Joe Gaydos using a hydrophone to listen to underwater sound in Haro Strait. © Steve Ringman, The Seattle Times

If you were short of breath, or feeling sluggish, you’d probably decide to go see a doctor. Your doctor would measure your breathing and heart rate and compare these to normal values. Similarly, in whales, abnormal behavior can be a powerful early warning that a whale is in trouble. 

Fortunately, we have longitudinal data on breathing rates and swimming speeds of individual whales of known age and sex going back to 2003. We collect the data from land-based viewing sites using a surveyor’s theodolite as a completely noninvasive way to measure impacts of vessels on SRKW behavior, including foraging. We’ve reused the data to map foraging hotspots, and we are showing how the distribution of those foraging hotspots changes between good and bad salmon years. We’ve even used the data for noninvasive physiology studies that showed that a mother orca needs 42% more calories when she has a calf swimming beside her to keep up with the group.

Now, we are reexamining those meticulous data records and are finding hints that “whales of concern”, (meaning whales that have poor body condition and may not survive the season) tend to take shorter breaths and feed less often than healthy whales of the same age and sex. We believe the whales’ behavior can tell us when they are sick, long before they show up skinny or with that characteristic sign of fat loss behind the head (peanut-head) that indicates that a whale is near death. If we can detect warning signs sooner, then we can get wildlife veterinarians like Joe Gaydos out on the water to test whether an individual has a treatable infection, or would benefit from treatment for parasites.

Southern residents in their Salish Sea home. © Lindsey Stadler

Southern residents need our help now more than ever

There is a perception that the SRKW population has always been small, and it fluctuates between 70 and 100 individuals. What this last year of working with top experts in genetics, population dynamics, wildlife health, and ecotoxicology has taught us, is that the whales are telling us something. There is a pattern here. We are not seeing random fluctuations in a small population. We are seeing a population declining by 1% per year, on average. Due to lack of mature females and inbreeding, that decline will accelerate toward extinction if we don’t mitigate threats now. We need all hands on deck to keep whales from getting sick, and sick whales from dying. And we need your help.

Conservation is a crisis discipline. Agencies tend to react to crises after they’ve become too obvious to ignore. If we’re going to prevent the extinction of our beloved southern resident killer whales, we need to look forward, not back. Frankly, that innovation comes from the conservation science sector, not the management sector, and it is fueled by individual philanthropists like you, not government grants. 

The southern residents need your help now. As Oceans Initiative urgently scales up our work on the relationships between killer whale behavior, health, and population growth, we hope our community will turn their dedication into action. Can we count on your support today to help fund our continued research and the development of our SRKW behavioral health metrics program?

Museum collections: time capsules for parasites of the past

by oceansadminWildlife HealthPosted on No Comments

“Parasitism may play a role in the recovery of at-risk marine mammals, but without digging in and figuring out if this is a new problem or status quo, we won’t know.” 

— Natalie Mastick

Posted originally at nataliemastick.com/blog/

There are indents on my nose, my hair smells faintly of ethanol, and I am actively working on realigning my spine after several hours hunched over a microscope. I have just wrapped up a fish dissection, but not a normal fish dissection of a fresh or even thawed fish. This fish was caught in 1985. Once captured, it was fixed in formalin and then stored in ethanol, living in a jar in the Burke Museum’s fish collection at the University of Washington for the last 35 years. This dissection is a small piece of the Wood lab’s effort to reconstruct the past of Puget Sound, and the parasites that lived in it. Each fish preserved contains a snapshot of what parasites infected it when it was caught and subsequently stored in ethanol, to live on a shelf for eternity. By dissecting the species commonly caught in Puget Sound and stored over the past century (that’s right, 100 year-old fish!) we are able to see how parasite diversity has changed in the region.

This has important implications for the fish that these parasites infect. Some of the parasite species found in fish use that fish as their definitive host; they’ll live in that fish for the rest of their lives. Other species, however, use the fish as a stepping stone–or intermediate host–to get to their ideal definitive hosts. These parasites wait until their intermediate host gets eaten, hopefully by a definitive host that they can infect for the rest of their lives. The parasites found in the fish represent the transferable parasites that were inhabiting the environment at that time, available to be eaten by a definitive host.

A group of these parasites are parasitic nematodes (worms) of the family Anisakidae, or anisakids, which I discussed in my blog post “Anisakid risk to endangered marine mammals.” These nematodes have multiple life stages, in which they depend on different hosts. Their first host, or primary host, is a copepod, which then gets eaten by a small fish or squid. In this second host, the nematode encysts in the muscle and waits to get eaten by the next biggest animal, hopefully a marine mammal (a whale, dolphin, seal, sea otter, or sea lion). Unfortuantely for the worm, from there it gets eaten by another fish. But evolution prepared them for this! Anisakids can keep getting eaten by fish and encysting them until they finally reach a marine mammal. Then, once they finally reach a warm-blooded host, they inhabit the stomach or intestine and reproduce. Those eggs are then sent out into the marine environment through the host’s feces, where they can get eaten by a copepod and the whole life cycle can begin again.

Aniskaids might play a bigger role in marine mammal health than previously thought. Once in the intestinal tract of a marine mammal, anisakids absorb nutrients from the host, taking up energy that would otherwise be used by the host alone. At larger burdens, large amounts of energy can be taken from the host, effectively acting as an energy sink. The whale or seal needs to eat more to account for this energy lost to its parasitic stowaways. But for at-risk or endangered species like the southern resident killer whale, which is already nutritionally stressed, parasitism by these nematodes may represent an additional stressor inhibiting the recovery of the species by acting in concert with other stressors.

In the lab today I was dissecting herring. Herring are an important forage fish in the Pacific Northwest. They form large schools and can be found in open ocean as well as bays. Herring are eaten by humans, fish, and birds, and they also make up a large part of the diet of some marine mammals, including whales, seals, sea lions, and porpoises. They form a foundation of the food web, so that the parasites that they harbor can continue on to a marine mammal, even if they are not consumed by one directly. By assessing how the abundance of anisakid nematodes has changed in herring and other fish, both small and large, that are common prey to marine mammals, I am uncovering how the risk to anisakid infection has changed locally over the past century.

While we are still in the dissection stages and not the analysis quite yet, I think we may see an increase in anisakid abundance. Marine mammals are key to the spread of anisakids in the marine environment, and surprisingly enough some marine mammals in this area have been increasing in number since protections were put in place in the 1970s (think of the skyrocketing populations of sea lions and harbor seals in the area). With more definitive hosts shedding eggs into the environment, the likelihood of infection of fish and subsequently of other mammals increases. I expect that this will be evident through the historical record we’re currently examining.

It is important to determine what parasite abundance in the ecosystem was like in the past because it provides context for what we see today. A component of my research is assessing how parasitized marine mammals in the area are now, and if parasites are likely impacting the health of marine mammals more than they were in the past. If we don’t know what the past was like, we can’t tell if marine mammals today are any worse off now than they were before, especially the at-risk ones like the endangered southern resident killer whale. If at-risk species are facing a more significant threat from parasites today than they were in the past, then those threats could be incorporated into their management. Parasitism may play a role in the recovery of at-risk marine mammals, but without digging in and figuring out if this is a new problem or status quo, we won’t know.

Anisakid risk to endangered marine mammals

by oceansadminWildlife HealthPosted on No Comments

“There are vulnerable marine mammals around the world. If these species are also facing an increase in parasitism, that may be an added stress impacting their rate of recovery.” 

— Natalie Mastick

Posted originally at nataliemastick.com/blog/

Until last year, my research revolved around whale foraging behavior. I studied the foraging behavior of humpback whales for my masters and spent several summers in the San Juan Islands studying southern resident killer whale behavior in response to shipping noise with Oceans Initiative. When I met Chelsea Wood, a parasite ecologist at the University of Washington, while scoping out PhD advisors it dawned on me that there was a whole other scale of foraging ecology to consider in whales— that of the parasites living within them.

I had worked with sick marine mammals before and assisted on a handful of necropsies at that point. Parasites were relatively commonplace, but generally not the cause of rehabilitation for the sick animals or death for those we necropsied. I had grown accustomed to ignoring parasites and assuming their effects were negligible. But after meeting Chelsea, it was clear that parasites may play a bigger role in animal health and survival than I had given them credit for. I had been studying southern resident killer whales with Oceans Initiative for several years, working on assessing the impacts of a suite of threats to the population. I thought more about the role parasites might play in an endangered species like the southern resident killer whales, whose recovery is inhibited by multiple stressors. For marine mammals that are already facing a multitude of threats, parasites could be an additional burden that might make the difference between a healthy and a sick animal.

Marine mammal parasites are nearly as widespread as their hosts. Parasitic nematodes of the family Anisakidae, or anisakids, are transmitted to marine mammals through the fish that they eat. Anisakids travel up the food web from copepods to fish or squid until they reach a marine mammal, their definitive host. They inhabit their host’s intestinal tract, reproducing and sending their eggs back into the ocean via their host’s feces to continue the cycle. These parasites can infect a wide range of fish species, leaving many marine mammals vulnerable to infection if their prey harbor anisakids.

There is evidence that anisakids are on the rise around the world. This led me to wonder, are these parasites increasing in the prey that marine mammals eat? And could the most vulnerable marine mammals be at risk to increases in parasitism? This seemed like an important question to address from a recovery and management standpoint. There are vulnerable marine mammals around the world. If these species are also facing an increase in parasitism, that may be an added stress impacting their rate of recovery.

The first chapter of my PhD has focused on answering these questions in some of the most at-risk species— those listed as threatened or endangered in the Endangered Species Act and the IUCN Red List. My lab-mate Evan Fiorenza recently completed a major meta-analysis of the publications on anisakid prevalence over the last 60 years. I compared the ranges and diet species of all IUCN listed species and ESA listed populations, resulting in 14 populations that overlapped with this meta-analysis dataset, ranging 30 years. I also subset the data to look at the species with the most data to see if there was a trend in any of the most well-represented diet species, grouped by the mammal that eats them.

As I am still actively analyzing the data, it is too soon to say whether there has been a change in anisakid abundance in the prey that endangered marine mammals are eating. That being said, I am excited to be presenting my preliminary data and analyses at the World Marine Mammal Conference in Barcelona this week. With any luck, I will be able to talk to some of the experts on these endangered marine mammals to gather more information about their diets to improve the resolution of my study. When I return, I plan to work on increasing the scope of my study to include species listed under Canada’s Species At Risk Act (SARA), and working with the experts at Oceans Initiative to improve range estimates of these species. But for now, I am excited to soak in new information more from the world’s marine mammalogists over the next week.

Pacific white-sided dolphin dorsal fin photos and breath samples

by oceansadminDolphins, Populations, Wildlife Health, Women in SciencePosted on No Comments

In August, part of our team traveled to the Broughton Archipelago off the coast of northern Vancouver Island to continue our long-term study on Pacific white-sided dolphins.  This study is multi-faceted. We are studying the health of the population by taking dorsal fin photos for statistical analysis, but we are also studying the health of individuals by looking for pathogens in exhaled breath. We’ve just celebrated the 10th anniversary of this study, but we made a few changes along the way. This year, with the help of Alimosphere, we were able to look at dolphin pods we encountered from a new perspective through the use of Unmanned Aerial Systems (UAS), also known as drones.

Drone footage collected under permit, by Alicia Amerson.

This year, we are sponsoring our research associate, Natalie Mastick, to start an exciting PhD project in marine parasite ecology. As she explains in a recent blog post, taking photos of dorsal fins is a non-invasive way to study the population that allows us to identify individuals that we can use as statistical samples in models to estimate survival rates, and population size and trends. High-resolution dorsal fin photographs show us distinguishable details such as nicks, scars, and markings that help us to recognize individuals from year to year. The Pacific white-sided dolphin study launched by our co-founder, Dr Erin Ashe, has involved taking, processing and matching dorsal fin photos to previous catalogues since 2007. Some individuals have been seen in the study area since the 1990s, and we have seen one pair of dolphins together on two occasions 17 years apart.

Laurel Yruretagoyena, Oceans Initiative research assistant, aiding Dr Erin Ashe in taking dorsal fin photos for her long-term photo ID study. Look closely, like deckhand Molly Brown is doing, and you’ll see some dorsal fins in the distance!                               Photo credit: Laura Bogaard, 2018.

As a continuation of a study started by Erin in 2015, we also spent much of our time collecting exhaled breath samples from these dolphins. We collect breath samples by positioning a long pole with a petri dish attached to one end over a dolphin as it surfaces and exhales. This is a tricky activity that involves a knowledge of dolphin surfacing patterns, careful boat handling, precise timing, and skillful maneuvering on the bow of the boat. Despite the difficulty, our team was able to collect many breath samples that we will use to assess the pathogens (e.g., viruses, bacteria and fungi) this population has been exposed to. Ultimately, we aim to let the health of the dolphins tell us something about the health of their environment. Understanding how pollutants impact marine mammals and their habitat is essential to informing recovery efforts and monitoring ecosystem health.

A beautiful crisp morning spent with energetic Pacific white-sided dolphins off Vancouver Island.                                                 Photo credit: Dr Erin Ashe, 2018.

Next year, we are hoping to invite Alicia Amerson from Alimosphere to the Pacific Northwest to join us in the field again for a workshop on using UAS for noninvasive marine mammal research. We aim to offer this opportunity to other women in marine mammal science, and to our entire staff. We hope this will provide us with a new tool for collecting breath samples in the future, in a continuation of our efforts to use minimally invasive field research techniques. As we close out our field season, we  are so thankful for the support we have received to do this important work.

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

by oceansadminAcoustics, Conservation, Exploration, Habitat, Human Impacts, Killer Whale Conservation, Ocean Noise, Protecting Species, Sustainable Fisheries, Wildlife Health, Women in SciencePosted on No Comments

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.