Peer-reviewed Publicat...

Invasive isopods in the Salish Sea

Juvenile invasive isopod Ianiropsis serricaudis on alga. Scale bar 0.3mm. Photo by Eric Lazo-Wasem, from Hobbs, et al., 2015

Juvenile invasive isopod Ianiropsis serricaudis on alga. Scale bar 0.3mm. Photo by Eric Lazo-Wasem, from Hobbs, et al., 2015

A recent publication on the global introduction of the Asian isopod Ianiropsis serricaudis was a by-product of a study we funded to evaluate the impact of invasive tunicates in the Salish Sea (Cordell et al., 2012). The publication shows that this invasive isopod is well-established in communities of fouling organisms throughout the Northern Hemisphere.

While the actual ecological impact of this isopod in the Salish Sea (or in other areas where it has been introduced) is unknown, it is interesting that in multiple places, including Puget Sound, its presence is strongly associated with the introduced tunicate Didemnum vexillum or with other introduced ascidians including Botrylloides violates and Styela clava.

Sometimes, such as with this paper, science only reveals small pieces of the mosaic, but with continued work it ultimately helps us see and understand the larger picture, which hopefully will permit us to better design health coastal ecosystems!

Growing up underwater: harbor porpoise muscle development

Harbor porpoise by Florian Graner. Licensed through NaturePL.com.

Harbor porpoise by Florian Graner. Licensed through NaturePL.com.

 

Peer-reviewed publication:

Noren, S. R., D. P. Noren, and J. K. Gaydos. 2014. Living in the fast lane: rapid development of the locomotor muscle in immature harbor porpoises (Phocoena phocoena). Journal of Comparative Physiology B. December 2014, Volume 184, Issue 8, pp 1065-1076.

 

This study -- based on harbor porpoise tissue samples collected from strandings, fishery bycatch, or observed killings by killer whales -- looked at muscle development in juvenile harbor porpoises to understand how fast they mature into physically competent adults.

This is important because it shows that immature harbor porpoises can't dive as well as adults and consequently have limitations on the kinds of habitat they can use. It brings attention to the concept that what might be okay for adult harbor porpoise (such as a certain level of boat traffic), might not be something that harbor porpoise calves can deal with as well as adults can.

Growing Up Underwater

Humans aren’t born ready to hunt down game animals — or even order Chinese food. We need mothers to protect and feed us at least until we can read a take-out menu. Life is somewhat similar for baby dolphins and porpoises.Diving ability in marine mammals depends on specialized biochemistry. High concentrations of myoglobin provide oxygen to muscles so divers can remain active while holding their breath. They’re also able to buffer the flush of lactic acid from anaerobic activity after the oxygen is depleted. It takes time, though, for newborn cetaceans to develop these special abilities.

A recent study by SeaDoc and Drs. S. Noren from UC Santa Cruz and D. Noren from National Marine Fisheries Service Northwest Fisheries Science Center (Seattle) used samples collected by the San Juan County Marine Mammal Stranding Network to measure diving capabilities in harbor porpoise, the Salish Sea’s smallest and most bashful cetacean. The results show that harbor porpoise achieve adult myoglobin levels by 9-10 months of age, and increased acid buffering as 2-3 year olds. This is faster than other cetaceans, which tracks with their earlier maturity and shorter lifespan. However, the study also proves that there is a period of time when harbor porpoise calves cannot keep up with the adults. This probably limits the habitat range and foraging of mothers and calves, leaving them vulnerable to habitat degradation.

SeaDoc and collaborators have recently undertaken a study to pinpoint harbor porpoise calving times so that we can further protect them at this delicate stage.

interesting facts about the study

  • This is one of the first studies to document muscle biochemistry development in dolphins and whales. It’s been done before with Fraser’s and bottlenose dolphins, but not with species resident in the Salish Sea.
  • Specimens for this research were collected opportunistically from stranded harbor porpoises, from animals caught accidentally by commercial fishing operations, and from animals killed by killer whales. Collection was performed through the San Juan County Marine Mammal Stranding Network. This program is administered through the Whale Museum and NOAA and is composed of a huge number of very dedicated volunteers.
  • Based on length, specimens were divided into 5 age classes, from fetus to adult.
  • A prior study by Dr. Shawn Noren, et al. (2008) points out that "although cetaceans are born directly into the ocean, the behavior of cetacean calves may mitigate demands that may otherwise drive the maturation of muscle biochemistry. For example, cetacean neonates typically swim in echelon position (calf in close proximity of its mother’s mid-lateral flank), which lowers the effort required by the calf to move at a given swim speed. Cetacean calves are also nutritionally dependent on their mothers’ milk for prolonged periods (8–42 months depending on the species; for review see Evans 1987) so that the calves do not need to dive to meet their nutritional needs. The distinctly different swimming styles and diving requirements of cetacean calves, relative to adults, alleviate the demands of physical activity and exposure to hypoxia early in life.”

Learn more about harbor porpoise in the Salish Sea

Harbor porpoise workshop: On February 7, 2013, the Pacific Biodiversity Institute, Cascadia Research Collective and the SeaDoc Society hosted scientists from Washington and British Columbia to determine the state of knowledge on harbor porpoises and coordinate ongoing research efforts. Read the statement identifying research needs.

Marine Science Lecture on harbor porpoise

Do river otters eat endangered rockfish?

In a sea filled with charismatic mammals like killer whales and Steller sea lions, it’s easy to overlook a smaller critter whose name might make you think it’s not even found near saltwater. However, as shoreline residents know, the Salish Sea is home to thousands of river otters. And with their fearless ways and fearsome canines—as well as their webbed toes and ability to dive at least 60 feet deep - these whiskered members of the weasel family are prodigious predators of marine species. A previous study in British Columbia found that otters fueled their high metabolisms in part by consuming a lot of rockfish, with up to a third of all scat samples containing rockfish remains. Since rockfish populations are so depleted that all fishing for them has now been banned on the US side of the Salish Sea, we needed to answer an important question: As we invest in rockfish recovery, are river otters eating up our profits?

To find out, SeaDoc-funded researchers visited otter latrines around the San Juan Islands. Otter scat was examined for fish bones and otoliths (ear bones) to determine species and age of prey. Otters are indeed seafood fanatics: fish were present in 100% of the samples.

Fortunately for our endangered rockfish, though, the otters seem to specialize in the small lower intertidal and shallow subtidal fish such as the gunnels, sculpins, and pricklebacks. Rockfish occurred most frequently in samples from San Juan Island (22%), and most rarely (2.7%) Fidalgo, Island. Also encouraging was that otoliths showed that less than half the rockfish taken by otters were adults - the breeders that are critical to replenishing rockfish stocks.

Tracking scat and identifying otter diet is the kind basic science that, with your generous support, is helping us piece together the incredibly complex ecology of the Salish Sea and understand how we can best restore it.

Can't access it through that link? Request a copy by emailing the office at seadoc@seadocsociety.org

 

 

Banner photo courtesy of Phil Green/The Nature Conservancy.

Eelgrass disease study investigates vulnerability to Labyrinthula

Eelgrass (Zostera marina) plays a key role in the health of the Salish Sea ecosystem. It stabilizes sediments, reduces the impact of wave action, provides habitat, and is an important nursery and foraging area for multiple species, some of which are endangered. SeaDoc's involvement in eelgrass issues goes back to 2003, when we convened a meeting of eelgrass experts, resource managers, and land-use specialists to analyze the sudden disappearance of 35 acres of eelgrass in San Juan Island's Westcott Bay.

Eelgrass can be damaged by pollutants, by shading from docks and structures, and by physical damage from improper anchoring or badly placed moorings. It's also susceptible to disease, particularly from a slime mold-like organism called Labyrinthula zosterae. And it’s no small threat. This disease wiped out 90% of the eelgrass along the Atlantic coasts of North America and Europe in the 1930s.

We know that the organism is found in the Salish Sea, but the mere presence of a pathogen does not always mean disease. So what are the other factors? A recent publication by Maya Groner and numerous colleagues (supported in part by SeaDoc) used field surveys and experimental manipulations to find out how the age of eelgrass leaves impacts disease prevalence.

The upshot: mature beds and shallow eelgrass beds could be especially susceptible to outbreaks of wasting disease.

View the publication here.

 

 

Banner photo from NOAA Photo Library via Flickr.

Hide and Seek Seabirds

Hide and Seek Seabirds

Marine birds are important sentinel species for ecological conditions and to track them, scientists often count the birds at the breeding colonies, which tells us the number of adults trying to breed. But for seabirds that nest in burrows like Rhinoceros Auklets and Tufted Puffins, it's hard to know how big the colony is because the birds, eggs, and chicks can be 15 feet down underground.

Salish Sea Marine Bird Project

Scoters-Surf-and-White-477-363.jpg
Peer-reviewed publication:

Vilchis, L. I. C. K. Johnson, J. R. Evenson, S. F. Pearson, K. L. Barry, P. Davidson, M. G. Raphael, and J. K. Gaydos. 2014. Assessing Ecological Correlates of Marine Bird Declines to Inform Marine Conservation. Conservation Biology. doi: 10.1111/cobi.12378. (Open access publication)

Where have all the birds gone?

The last 30 years have seen precipitous declines in many of the bird species that visit the Salish Sea during the winter.

Bird Studies Canada seabird survey

Using various tools, private money and strategic collaborations, SeaDoc made a substantial investment to understand the problem of declining marine birds. We recently completed research demonstrating that diving birds that eat schooling forage fish are the species most likely to be in decline.

Salish sea map

Tackling such a big issue is not easy. Understanding how we worked through this issue gives you a good idea of how SeaDoc can address what might seem to be insurmountable obstacles to healing the Salish Sea. It also shows you how private support makes our work possible.

Step 1: Identify the information gap

In 2005, SeaDoc brought researchers and managers from the US and Canada together to talk about the state of marine bird populations in the Salish Sea. It became clear that we were facing a big problem. Birds were declining in different jurisdictions, but it wasn’t clear how steep the declines were, which species were involved or what factors were behind these declines.

Because no one took a big-picture approach, bird restoration efforts were focused on one species at a time. But was there something going on at the ecosystem level causing multiple species to be declining?

We realized we needed an ecosystem-level look at which species were in decline and why.

Step 2. Get around transboundary roadblocks

Decades worth of data had been collected in Washington and British Columbia by the Washington Department of Fish and Wildlife (WDFW), Audubon, and Bird Studies Canada. But the organizations used different survey techniques and geographic scales so people had not been able to look at the data to get a perspective for the entire ecosystem.

Surf scoters and white-winged scoters are diving ducks in decline in the Salish Sea

SeaDoc was the ideal group to take on the challenge of merging these differing data sets from two different countries. State, provincial, and federal governments rarely have the time for this kind of effort. Also they have political constraints and pressures that make it hard to see past their borders.

Step 3. Hire a scientist to do the work

Collaborating with multiple groups, merging complex data sets and analyzing decades of data is a full time job for several years. Stephanie Wagner, a woman who loved the Salish Sea and its creatures, made a legacy gift to SeaDoc before she died. This gift provided the funding that allowed us to hire Dr. Nacho Vilchis to lead this important work.

Step 4. Use an epidemiological approach

Dr. Vilchis' first task was to get the data sets to “talk to each other.” WDFW conducts aerial transects from a plane. Bird Studies Canada and Audubon use point counts. Both are good techniques, but they produce surveys that are difficult to compare.

Spotters conducting an aerial survey for the Washington Department of Fish & Wildlife. Photo: Joe Evenson/WDFW

Nacho, who has a background in the statistical manipulations of large data sets, found a way to combine and use the three surveys in one overall analysis. Then he trimmed the set down to just 39 core species, removing the occasional visitors and the birds for which he didn’t have enough data to draw robust conclusions.

He also used GIS maps of the Salish Sea to connect each data point not only to a geographical area but also to major habitat characteristics, such as water depth.

Drawing heavily on the “Doc” part of SeaDoc, we used an epidemiological approach to find a likely diagnosis. Just as the family doc quizzes you for risk factors for diabetes or heart disease, SeaDoc found that two lifestyle factors among seabirds correlated to a very high risk of population decline.

Step 5. Translate results into recovery

The work, published in the internationally-acclaimed peer-reviewed journal Conservation Biology, showed that birds that dive to find food are much more likely (11 times as likely) to be in decline compared to non-divers.

Surf smelt are an important  source of food for birds and other predators. Photo: J. Gaydos

But it’s worse if you’re a diver on a restricted fish diet. Diving birds that focus their efforts on small schooling fishes called forage fish were 16 times as likely to be in decline. Forage fish are small schooling fish that convert plankton into fat and are eaten by other fish, birds and mammals. These include herring, smelt, anchovies, eulachon, sardines, and sand lance.

But publishing a paper is not the end. It actually is just the beginning. This paper is now being used by scientists, managers and policy makers as evidence for the need to recover marine birds. Recovering forage fish will not just benefit birds, however. Because forage fish turn plankton into fat that’s available for other animals, they are a key part of the ecosystem and their recovery will benefit salmon, lingcod, rockfish, harbor porpoise and many other species within the Salish Sea.

Four key factors made this project successful.

1. Good data

Dr. Vilchis could not have conducted this analysis without scientists and citizens having already spent decades collecting rigorous data. The collection of these data took money, persistence, and forethought.

2. Collaboration

Photo: J. Gaydos

From the beginning, this project has been a story of collaboration. From the individuals collecting data over two decades to the senior scientists who worked out a way to share their data, it’s taken the work of many people working in different jurisdictions to make this happen. Our collaborators shared three huge datasets collected on two sides of an international border. They only did so because they were confident that SeaDoc would be able to use the data to produce robust scientific results.

3. Working on the level of the ecosystem, not the politics

This was the first study to look at bird declines across the entire Salish Sea marine ecosystem.

Most Canadian or US maps stop at the border, but the Salish Sea does not. Too often, the mandates and responsibilities of the people who work at the various state, provincial, and federal agencies tasked with keeping wildlife populations healthy also stop at the border.

View from the WDFW seabird spotting plane. Joe Evenson/WDFW

SeaDoc, being privately supported by people like you who understand how important it is to treat the ecosystem as a whole, works across the entire ecosystem.

4. An extraordinary legacy gift

In the end, one person's financial gift made this project possible.

Without Stephanie Wagner’s legacy gift, this project would have been just a good idea that never got done. Instead, we made it someone’s job to find the truth that was hidden in the data.

Stephanie Wagner’s thoughtful gift enabled us to point clearly to a hidden problem affecting the productivity of the entire Salish Sea ecosystem. With her gift we were able to do good science that will make a difference in how scientists and managers work on healing the Salish Sea.

Put plainly, money can change the world for the better.

Please contact SeaDoc or your financial advisor if you’re interested in including SeaDoc in your will so you can leave a legacy for the health of the Salish Sea.

Photo: Karen Barry/Bird Studies Canada

Alien Invaders: Invasive tunicates and shellfish aquaculture

Alien Invaders: Invasive tunicates and shellfish aquaculture

While headlines about invasive tunicates have at times reached the breathless pitch of ads for campy horror films, there was legitimate concern because invasive tunicates in other regions of North America have severely impacted the aquaculture industry. Our Pacific Northwest shellfish industry annually pumps millions of dollars into the local economy. Introduced tunicates could potentially cause ecological and financial disaster.

Bears and Barnacles: The Land - Sea Connection

bear cub eating barnacles-Jim Braswell

 

Videos

Why make a list of all the birds and mammals that depend on the Salish Sea? Joe Gaydos explains. (1:18)

 

Part 2: Why has this never been done before?

 

In Part 3, Joe talks about:

  • the challenges in assembling the list,
  • how it can help scientists (including SeaDoc's own Dr. Nacho Vilchis),
  • how the list indicates when and how heavily different species use the ecosystem,
  • how they tracked down citations for each and every species, and how fox and beaver have been shown to use the intertidal zones.

At about minute 4:30 Joe talks about how the tidal marsh beavers not only use the marine resources, but also contribute to the health of salmon populations. Pretty interesting stuff.

Click to see a picture of a beaver dam in the Skagit River delta.

Get the Checklist

We've created a printable checklist of all the bird and mammal species that depend on the Salish Sea.

Download a copy

You can print the checklist on two sides of a single sheet of paper and take it with you on your travels.

Read the scientific paper

Click here to go to the citation page where you can find a link to the scientific paper.

The Photographer

Big thanks to Jim Braswell for sharing his extraordinary images. Please visit Jim's nature photography site at http://www.showmenaturephotography.com where you can see more of his photographs and learn about his photography & photo editing workshops. 

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River Otters, Sea Otters, and Toxoplasma gondii

For several years we’ve been working to better understand what impacts the health of river otters in the Salish Sea. While the Pacific Northwest is fortunate to have a robust river otter population, more than 20 states are spending millions of dollars to bring back wild river otters.