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.

Where are the Southern Resident killer whales?

by oceansadminKiller Whale Conservation, WhalesPosted on One Comment

“We hope that they are finding fish in peaceful, clean waters. And when they return to the Salish Sea, we will be waiting for them.”

— Sarah Colosimo

It’s another beautiful summer on San Juan Island for our field team, where the days are long and end with glorious sunsets. Seal pups and fawns mark the beginning of new life. And the town is bustling with tourists who have come to see the resident star attraction of the islands; but the whales are not here.

We haven’t seen the Southern Resident killer whales since their fleeting visit in early July. Their appearance spanned the course of two days as they performed their classic “westside shuffle” along the shores of the island at a hasty speed, treating those who were lucky enough to witness this brief encounter. As quickly as they appeared, they too quickly disappeared. It has now been over a month since we have seen them.

The absence of the whales we know and love from these inland waters this summer is unprecedented and impossible to ignore. It is particularly prominent for us, given the purpose of our team being on island is to observe these whales. However, the reality begs us to accept that the whales are not here because this is no longer a viable habitat for them. Perhaps the whales have finally realized this too, and are unable to energetically contend with the declining salmon runs, vessel noise, and toxins that have become the reality of the Salish Sea.

Waiting for Southern Resident killer whales on San Juan island. © Farrell McClernon

The story of the Southern Resident killer whales is undoubtedly devastating. Last summer, we watched on from the shore as a mother carried her deceased calf for days on end and as a starving juvenile wasted away until she eventually disappeared. As their numbers continue to decline, with additional missing whales this year, it is hard not to feel as though all is lost and the damage is irrevocable. But we urgently need to escalate our efforts to restore the Salish Sea in the hopes that the whales will return, before we lose them forever.

It is bittersweet to be without the Southern Residents this summer. While we are without our study species in the place that has historically been considered their critical habitat, we can only hope that it is because they have found an abundant source of salmon that is filling their bellies and supporting their survival. If there is anything that these whales have demonstrated to us, it is the ability to endure and persist. Wherever the Southern Resident killer whales are, we hope that they are finding fish, in peaceful, clean waters, and when they return to the Salish Sea, we will be waiting for them.

Show your love for the ocean

by oceansadminConservation, Killer Whale ConservationPosted on No Comments

Are you in a healthy relationship with the ocean?

You love the ocean. We love the ocean. Let’s work together to protect it. (PC GGraphics)

Valentine’s Day is all about making sure we don’t take the people we love for granted. Sometimes it feels as though we’re taking the ocean for granted, even though it’s the 71% of the planet that gives us the air we breathe, much of the food we eat, the way we transport goods around the globe, and supports the miraculous wildlife that sparks so much joy. How can we show our love for the ocean?

Right now, people are pulling together to show their love for our endangered orcas any way they can. We use science to find solutions that help us protect endangered species while supporting the people who earn a living from the sea. We are working to reduce bycatch of dolphins, whales, and other ocean creatures by making fisheries more sustainable. Our ongoing efforts to measure and reduce ocean noise can make it easier for whales and dolphins to find food, mates, and navigate an increasingly noisy ocean. Our work on dolphin health provides a glimpse into which pathogens may affect whales, dolphins, and other marine mammals in the Pacific Northwest, and aims to draw a direct link between what we dump into the sea and how the ocean ecosystem is affected.

You don’t have to be a marine biologist to have a positive impact on ocean conservation. The choices we make as consumers can have a ripple effect that encourages industry and policy-makers to embrace ocean-friendlier practices.

Here are five ways to show your love for the ocean. What did we miss? Please share your ideas in the comments!

  1. Reduce your plastic use. Pass on the plastic straw and use re-usable cups. Some of our favorite go-to thank-you gifts are these custom Oceans Initiative pint cups and coffee mugs from our friends at MiiR.
  2. Buy locally and support local artists: 90% of everything comes to us from ships, which are important sources of carbon emissions and underwater noise. Buying locally reduces our shipping footprint. This year, a lot of our gifts include sweets from Seattle-based Joe Chocolates and custom orca stickers from the talented artist, Sophia Trinh. Sophia even offers painting classes, so you can give the gift of experiences, not things.
  3. Choose and support sustainable seafood: Ask your local grocer, farmer’s market, and restaurant about the source of their seafood. It makes a difference. Aim for wild, locally caught seafood that has MSC certification. If you already do this, you can go further to help southern resident killer whales. In the wake of the tragic story of Talequah and the ongoing struggle of the orcas, Chef Renee Erickson made a bold decision last summer to pause serving Chinook salmon in her restaurants. We love giving Renee’s excellent cookbook to our friends and family. Feeling bold? Eat invasive species! Totally guilt-free eating. You’re doing the ocean a favor.
  4. Get out and enjoy the ocean! Go for a walk on the beach, organize a local beach clean-up, surf, paddle, sail, learn about a new whale, fish, or other sea creature, paint or create your favorite ocean art. Have a nap on the beach.
  5. Find a marine conservation nonprofit whose work you like, and support it. Spread the word about their work. Convince a friend to support it. Make a charitable donation in the name of someone you love. It doesn’t have to be us (but we’d be thrilled if you did support our work, of course). Honest. Find the group whose mission sings to you, and get involved.
Pacific Northwest classic gifts (clockwise from top left): Chef Renee Erickson’s cookbook is a love song to the Pacific Northwest; Sophie Trinh’s whale stickers and paintings are magical (& she even offers painting lessons); Joe Chocolate is a sweet, local company; and MiiR’s reusable cups and mugs are lovely and handy in a town that runs on coffee. What are your go-to gifts?

How do you show your love for the ocean?

Underwater noise from airplanes: An overlooked source of ocean noise

by oceansadminAcoustics, Exploration, Ocean Noise, Women in SciencePosted on No Comments

We tend to think of the air-water interface as a barrier to noise. Planes fly over the ocean all the time, but conventional wisdom tells us that most of the sound bounces off the surface of the ocean, and has little impact on the whales and dolphins that swim beneath the surface. A classic paper from 1972 tells us we only need to worry about airplane noise in a narrow cone under the flight path.

We recently worked with colleagues from Curtin University, Udayana University, and Conservation International Indonesia to measure noise levels from commercial jets taking off from coastal runways in Bali and Australia. We found that under certain conditions, those jets introduce up to 130 dB of noise into shallow waters. Those noise levels are high enough to cause disturbance to killer whales.

Planes fly pretty quickly of course, so any noise exposure is fleeting. But during the busiest periods, we recorded planes taking off every 3 minutes! Below is a map of runways, with coastal runways (<10 m above sea level) in red.

We conducted this study during Nyepi, the Balinese Day of Silence. We did not expect to be able to hear airplane noise over background conditions, but we got lucky. Did you know that fish have a chorus of song, just like the dawn chorus of songbirds? Check out the sounds of fish singing below:

And this is the sound of a small boat passing by our hydrophone. In the last few seconds, you can hear the roar of a jet aircraft taking off from the nearby runway of Denpasar airport, Bali, Indonesia.

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Runways of the world, with coastal (<10m above sea level) marked in red

 

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.

[KGVID]https://oceansinitiative.org/wp-content/uploads/2018/09/WISHART-1.3-Back-and-Side-Audio.m4v[/KGVID]

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.