Wildlife Posts

Predator Versus Prey: An Eagle's Eye View

Predator-prey relationships are strong evolutionary drivers and prime movers and shapers of our natural world. They also make for dramatic stories that seem to portray black-and-white cases of cause and effect. Ecosystems, however, function at such a high level of complexity that seldom are things as straightforward as they appear.

In Yellowstone, introduced wolves take down elk and the park’s forests grow and streams revert to meandering courses. In the Salish Sea, seals and sea lions are protected and salmon populations crash. Along the Pacific flyway, we stop poisoning and shooting bald eagles and suddenly seabirds are struggling.

Fishes of the Salish Sea

Dragons and Vipers and Opahs, Oh My!

Sailfin sculpin by Joseph R. Tomelleri
Sailfin sculpin by Joseph R. Tomelleri

The Salish Sea's famed salmon have a lot of interesting company beneath the surface. From the gumdrop-size spiny lumpsucker to the world's second-largest fish, the basking shark, we've long known our inland sea was home to an amazing range of fish species. However, it wasn't until an exhaustive new SeaDoc-funded study set out to document every species of local fish that we fully understood the diversity of these rich waters.

The study, by Ted Pietsch and Jay Orr, revealed more than three dozen fish species not previously known to inhabit the Salish Sea, adding such notables as the leopard shark, Pacific hagfish and lowcrest hatchetfish, and raising the number of local fish species to 253. Another "new" native, the opah, is a freckled orbicular oddity and one of the only known warm-blooded fish.

Beyond the wonder of knowing we share our Salish Sea with the opah and other fantastical creatures like the ribbonfish and daggertooth, and that our abyssal depths twinkle with such bioluminescent stars as the flashlight fish and viperfish, we now have a definitive list that allows us to more accurately choose which fishes best serve as indicator species — the canaries in the aquatic coal mine — to track the health of the entire ecosystem. It will also tell us when invasive species invade, and if any native fishes disappear.

This important paper proves once again that when it comes to restoring the Salish Sea, good science and SeaDoc donors really count.

Download the paper

Fishes of the Salish Sea is an open-access publication of NOAA, available for download from the SeaDoc website or from the NOAA website.

The PDF includes about a dozen incredible drawings of local fish.

More details about the study

This study is part of a long-term effort by SeaDoc to document the fish and wildlife that inhabit the Salish Sea.

In 2011, Joe Gaydos and Scott Pearson published "Birds and Mammals that Depend on the Salish Sea: A Compilation" in Northwestern Naturalist. That paper established a baseline list of species, and has been cited numerous times in both peer-reviewed and technical papers.

Now we have a complete list of fishes. At some point we hope to take on the daunting task of cataloging the 3,000+ species of macro-invertebrates.

Knowing which species use an ecosystem and how they make their living is fundamental to restoring it.

Why is this so important? With this list, scientists will be able to document the occurrence of new species and the disappearance of existing ones. The list will be a key baseline for Salish Sea recovery. At the same time it will help scientists select particular species as indicators of ecosystem health, and it will provide a basis for identifying the mechanisms responsible for marine fish declines.

Funded by private citizens

Like many SeaDoc projects, this one was funded by individuals with a commitment to the health of the Salish Sea. Thanks to our forward-thinking donors for understanding the importance of this effort and making it possible.

 Blacktail snailfish by Joseph R. Tomelleri

Blacktail snailfish by Joseph R. Tomelleri

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.

Tracking Transboundary Trouble

 Basking shark copyright Florian Graner. Used with permission.

Basking shark copyright Florian Graner. Used with permission.

How do you know if your ecosystem is in trouble? One clue is the number of species that are in decline or endangered. If that number gets bigger over time, you’re probably heading in the wrong direction.

Publications

We publish our Species of Concern analysis approximately every two years in conjunction with the biennial Salish Sea Ecosystem Conference.

In any particular year species might be added or removed from the list. For example, in 2008, 3 species were added, 2 were removed, and the listing status for 12 previously included species was changed by one or more jurisdiction.

Each jurisdiction in the Salish Sea (Canada, the United States, British Columbia, and Washington State) keeps their own list of species in trouble, but until 2002 nobody kept track of the total number of threated and endangered species in the whole ecosystem. Back then, SeaDoc scientists found a total of 60 species of Salish Sea invertebrates, fish, reptiles, birds, and mammals that we needed to worry about.

Thanks to your support we’ve been able to repeat the analysis every two years. Unfortunately, the list keeps growing. Our latest accounting showed that the total number of species at risk has now nearly doubled, to 119. Recently listed species include the Basking shark, North Pacific spiny dogfish, Pacific Ocean perch, and Baird’s beaked whale. The fact that the list has almost doubled is a bad sign, and it suggests that our entire ecosystem is at risk.

Your support enables us to take on these long-term, ecosystem-level initiatives that allow us to diagnose, and eventually reverse, problems like transboundary species declines. Thanks to your investments we’re able to publish scientifically rigorous metrics that help citizens and policy makers understand the big picture.

Type Percentage Listed Ratio
Macro invertebrates 1% 2/3000 (estimated, from unpublished data)
Reptiles 100% 2/2
Fish 17% 42/253 (Pietsch and Orr, in press)
Birds 32% 55/172 (Gaydos and Pearson, 2011)
Mammals 35% 13/37 (Gaydos and Pearson, 2011)

The high proportion of species of concern is suggestive of ecosystem decay (Bierregard et al., 2001) and we suggest that it is time to consider the entire Salish Sea an ecosystem of concern. Increased funding and improved efforts to recover declining populations of species and recover this ecosystem are urgently needed to stop the insidious loss of species and ecosystem decay.

 Spiny dogfish by NOAA’s National Ocean Service  CC

Spiny dogfish by NOAA’s National Ocean Service CC

Award-winning presentation

At the 2014 conference, the 2013 paper was presented by co-author Jacq Zier, who won first prize in the undergraduate division for an oral presentation.

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.

Seals on the Run

seal with transmitter

Every summer, dozens of stranded baby harbor seals are brought to centers where they’re rehabilitated and released back into the wild. People expect these animals will behave like wild seals. But do they?

To find out, SeaDoc and colleagues satellite-tagged and tracked 20 harbor seal pups – half rehabilitated, half naturally weaned. The differences were big. Rehabilitated seal pups took off like torpedoes after release, traveling three times farther daily and dispersing three times as widely as the wild ones. And the rehabbed pups only transmitted signals for half as long as their wild cohorts, which could relate to how long they survived.

What’s extra fascinating here is that we’re talking about a mammal that spends just a single month nursing before it’s left on its own to survive. But if human-reared pups are traveling so much further, it could mean that wild pups actually learn quite a bit about foraging in the short time they spend flippering alongside their mothers, even if they’re only nursing and not catching fish. It could also mean that wild pups “imprint” on a local area during their first month. Or it might mean that rehabbed pups are naive to navigating the strong currents that sweep through the San Juans. It is time to learn how best to enhance rehabilitation techniques to get pups behaving more like wild seal pups after release. 

More Information:

tracking mapSeaDoc's paper was written by Joe Gaydos and Ignacio Vilchis of the SeaDoc Society (UC Davis), Monique Lance and Steven Jeffries of the Washington Dept. of Fish and Wildlife, Austen Thomas of the University of British Columbia, Vanessa Greenwood and Penny Harner of Wolf Hollow Rehabilitation Center, and Michael Ziccardi of the Wildlife Health Center at UC Davis.

The abstract is here. If you would like a copy of the full manuscript please email your request to seadoc@seadocsociety.org.

This study was funded by NOAA's John H. Prescott Marine Mammal Rescue Assistance Grant Program and private donations from SeaDoc supporters, including a significant donation from Bill and Lannie Hoglund. For this particular study, the private donations were a critical part of the mix because the Prescott funds could not be used to study wild-weaned seals.

Overview of post-rehabilitation research:

At the 2012 North American Veterinary Conference, Joe Gaydos gave an overview of the need for post-rehabilitation studies and reviewed the studies performed to date. He also discussed the role of veterinarians in marine mammal rehabilitation. Read the PDF.

Stranded seal recovery:

Stranded seals are generally found in the summer months. There are a number of reasons why pups become separated from their mothers, including illness, interference from dogs and humans, and maternal death. SeaDoc's summer interns assist with the Marine Mammal Stranding Network in the San Juan Islands. They often provide first-line veterinary response when pups are picked up and transported to the rehab center. 

Wild seal capture:

The wild-weaned seals were captured by the investigation team from a haulout location in the San Juan Islands. 

Keep your distance from marine mammals:

We always like to remind people that Federal law requires everyone to stay at least 100 meters away from marine mammals like Harbor Seals. Do not approach pups you think are stranded or abandoned. They may be just waiting for their mother to return, but if you approach you may scare off the mother and cause the pup to be abandoned. 

Harbor Seal facts:

Did you know the milk of harbor seals is 40% fat? Or that they can dive up to 600 feet? View more harbor seal facts.

Harbor Seal skeleton available for display:

SeaDoc has a mounted skeleton of a large male harbor seal found dead on a beach in San Juan County. The skeleton travels to schools, banks, and other public display locations to help people learn about Salish Sea marine mammals. If you're interested in displaying the skeleton at your place of business, get in touch. See pictures.

Surprise your friends with a Harbor Seal ringtone:

Just for fun, we took a recording of a squawking young seal and turned it into a ringtone for the iPhone. It sounds a little bit like a badly out-of-sorts child, and definitely gets some strange looks in the grocery store. Details.

 

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.