Zombies of the sea

It looks like something out of a science fiction movie: Arms peeling off and walking away on their own. Sometimes these lone arms even get eaten by other individuals.

Ossicle pile. Credit: Neil McDaniel, via http://www.news.sciencemag.org

In the summer and early fall of 2013, sea stars began dying on the west coast of North America from an unknown cause. The syndrome was first documented at Starfish Point on the Olympic Peninsula in Washington state (Science). Affected sea stars exhibited symptoms such as lesions, curling and twisting of arms, arm loss,  and “melting”. While sea stars can usually grow back an arm if they lose it, these stars were too sick to do so. Based on the symptoms, it appears that the disease affects the soft tissue of sea stars (One Health Institute, Elise LaDouceur), leaving behind ghostly piles of ossicles, the bony parts of sea stars that make up their endoskeletons. Sea stars were and are still being affected along the west coast of North America from Alaska to Southern California (Pacific Rock Intertidal Monitoring), as well as on the east coast of North America (Science).

Recent research by Ben Miner, a biologist at Western Washington University, and his lab have identified four general locations where sea star populations were dramatically reduced from the most recent wasting syndrome event, including Vancouver, BC, the Seattle area, Monterey Bay, and Santa Barbara, with other areas along the west coast from Alaska to San Diego, CA impacted to a lesser extent (SSEC). It is currently unknown why populations in Washington and California have been heavily affected, while those in Oregon less so (Science). The first sighting of an affected sea star in Oregon was recently made  last month (April 27th 2014) and affected stars such as sunflower stars, ochre stars, and giant pink stars have since been observed in Yaquina Bay, Oregon (Statesman Journal). 

Kimber Chard, an avid diver and underwater photographer local to the Seattle area, says he has seen affected sea stars at most of the popular dive sites near Seattle, including Mukilteo, Three Tree, Redondo Beach, and Cove 2 in West Seattle, and has photographed some of the affected stars. Chard, who is a master SCUBA diver with over 630 dives logged to date, says  that from what he’s seen underwater,”it’s evident that that’s [sea star wasting disease] what’s going on”. In popular dive sites like Cove 2, the number of sea stars has dramatically reduced (see video by videographer Laura James).

Multiple sea star species have been affected by sea star wasting disease. Washington state has upwards of 20 species of sea stars (Ben Miner, KQED-NPR), and many of these species are affected, including Solaster dawsoni (morning sun star), Evasterias troschelii (mottled star), Pisaster brevispinus (giant pink star), Pisaster ochraceus (ochre/purple star), and Pycnopodia helianthoides (sunflower star) that are experiencing high mortality (seastarwasting.org). Chard says that during his dives in the Seattle area he has seen a lot of healthy juvenile sea stars, seemingly unaffected by the wasting disease, providing some hope that sea star populations will be able to rebound in the area.

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Although sea star wasting events have happened before, a mortality event of this magnitude and geographic scale has never before been seen (seastarwasting.org, Colleen Burge). Previous sea star wasting disease events have also been shorter in duration, lasting from about summer-November (Colleen Burge), while the current event is lasting well into winter and the next spring. Previous sea star wasting events include a major die off in southern California in 1983-1984 and again in 1997-1998 (seastarwasting.org). Previous events have typically been associated with warmer water temperatures during El Niño events. However, this event carried through to winter for the first time, when waters are relatively cool.

Historic Sea Star Population Declines via Science.

Both captive and wild sea stars have been affected. Mortality in parts of the
Seattle waterfront and in the captive collection at the Seattle Aquarium was 100% (SSEC). However, sea stars at some facilities in tanks where sea water is treated and filtered did not become sick, suggesting that the wasting disease may be the result of an infectious pathogen.

In the past when pathological studies have been done to determine the cause of the disease, it was typically attributed to a bacterium (vibrio), although a recent wasting event on the east coast of the United States has been attributed to a virus (seastarwasting.org).  Other proposed hypotheses include novel pathogens introduced through ship ballast water, contaminated prey items (especially filter feeding animals that bioaccumulate toxins etc.), natural die offs, toxins, a virus, bacteria, manmade chemicals, ocean acidification, wastewater discharge or global warming. “It’s a huge huge mystery”, says Chard, who supposes that sea star wasting disease may be a result of a natural die off of sea stars due to unsustainable population numbers.

Colleen Burge, a posdoctoral researcher at the University of Washington, has been conducting exposure experiments on healthy naive sea stars to determine if the disease is transmissible (infectious) or non-infectious, an important step in understanding the disease. “The leg curling can occur pretty quickly post exposure, within the first few days, the lesions and arm loss occur between 14-22 days…progression is likely faster at greater temperatures”, says Burge on the progression of the disease in the laboratory. Based on the current evidence, “we believe this is an infectious disease”, says Burge.

Although some have suggested that the symptoms were a result of radiation from the Fukushima disaster, scientist have not found any evidence consistent with this hypothesis. In fact, while radiation from the disaster has probably reached the west coast of North America, it is not dangerous. As Kim Martini, a physical oceanographer at the Joint Institute for the Study of the Atmosphere and Ocean at the University of Washington in Seattle states in her blog post on the Fukushima disaster, “the additional radiation that was introduced by the Cesium-137 fallout is still well below the background radiation levels from naturally occurring radioisotopes.”, supporting the fact that sea star wasting disease is not a result of radiation.

Research groups and organizations involved in uncovering the cause for sea star wasting disease include  Cornell (Harvell & Hewson), University of Rhode Island (Gomez), Brown (Wessel), Western Washington University (Miner), University of Washington (Friedman), UC Santa Cruz (Raimondi), Friday Harbor Labs, Wildlife Conservation Society, SeaDoc Society,Monterey Bay Aquarium, Vancouver Aquarium, USGS National Wildlife Health Center, NW ZooPath, the Seattle Aquarium, MARINe, and others (seastarwasting.org; SSEC).  The research underway has already ruled out a number of potential causes, including fungi, protozoans, larger parasites, and some kinds of bacteria (Science). Marta Gomez-Chiarri, Professor at the University of Rhode Island, has found that in addition to sea stars, sea urchins and sea cucumbers can become sick as well.

Sea stars are not only iconic intertidal organisms, but also keystone predators that have a disproportionately large influence on the intertidal community. In his classic experiment in which he coined the term “keystone species”, Robert Paine of the University of Washington experimentally removed ochre stars (Pisaster ochraceus) from the rocky intertidal, and observed the effects of it’s removal. Once the predator was removed, mussels quickly took over and out competed other organisms, causing a dramatic shift in the community. Although sea stars have been established as a keystone species, it will be difficult to predict the effects of the syndrome on communities. Despite a large number of sea stars being affected, scientists are not concerned with a complete extinction of sea stars at this point, and are focusing their efforts on identifying the cause for the syndrome.

To document sea star wasting observations, please go here.

More information on sea star wasting disease:

KQED-NPR: What’s killing the starfish?

WNYC-BBC: What’s killing all the starfish?

Science for the People (starts at 28:00)

Science Magazine, News Feature: “Death of the Stars”

seastarwasting.org

Sea stars of the Pacific Northwest

Sources:

Personal communication with Kimber Chard.

Personal communication with Colleen Burge.

Science Magazine, News Feature: “Death of the Stars”

2014 Salish Sea Ecosystem Conference Abstracts, Benjamin Miner & Lesanna Lahner. 

The Statesman Journal: Sea star wasting disease arrives on the Oregon Coast.

One Health Institute. Video: Sea star wasting syndrome causing mass die-offs on the West coast. Elise LaDouceur. Resident, Anatomic Pathology. UC Davis School of Medicine.

Pacific Coast Rocky Intertidal Monitoring, Sea star wasting syndrome map.

KQED-NPR: What’s killing the starfish?

PBS. Video: Mysterious epidemic devastates starfish population off the Pacific Coast.

 

Pinto abalone to be considered for endangered species listing

Last week the National Marine Fisheries Service (NMFS) announced that it will conduct a status review for pinto abalone. Depending on what NMFS decides, pinto abalone could be listed as “threatened” or “endangered” under the Endangered Species Act. “Endangered” means a species is in danger of extinction throughout all or a significant portion of its range. “Threatened” means a species is likely to become endangered within the foreseeable future. This review is in response to a petition filed by the National Resource Defense Council (NRDC).

Pinto abalone are considered in threat of extinction in Washington State, as individual animals are too far apart to successfully broadcast spawn and are currently considered a “species of concern”. Species of concern are those species about which NMFS has concerns but have insufficient information to list the species under the Endangered Species Act. In an effort to restore pinto abalone populations in Washington State, a hatchery was developed to release juvenile pinto abalone into the wild. The Pinto Abalone Recovery project has many partners including the University of Washington, Shannon Point Marine Center, Puget Sound Restoration Fund and the Washington Department of Fish and Wildlife and others.

As I previously worked with pinto abalone, I was very interested to hear about this development. What does this possible listing mean for pinto abalone and the scientists who study them? I asked my past adviser Carolyn Friedman about her opinions on listing pinto abalone under the Endangered Species Act.

Carolyn Friedman is a professor in the School of Aquatic and Fishery Sciences at the University of Washington. Carolyn has been working with abalone for almost 30 years. She was the first to describe the causative agent withering syndrome decimating black abalone in California in her publication in 2000 and has continued researching black, red, and pinto abalone since then. She has been involved with the listing of black and white abalone. She is a partner on the Pinto Abalone Recovery project.

Q: What are the benefits of listing animals as endangered, threatened etc.?

A: Listing provides federal protection for the species. Bigger fines for taking (poaching) animals are associated with species protected under the Endangered Species Act (ESA). Heightened awareness of the plight of the ESA listed species is often associated with listing. Additional avenues for research and culture of ESA listing are also potential benefits.

Q:  How would listing pintos as “endangered” be different from if they were listed as “threatened”?

A: Endangered species are at risk of extinction throughout all or a significant portion of their range, while threatened species are at risk of becoming endangered and are, thus, considered to have a lower potential of extinction throughout much of their range. Endangered species have full ESA protection including the prohibition for anyone under U.S. jurisdiction of the U.S. to “take” (e.g., harm, injure, kill, capture, etc) the species. When a species is listed as threatened, those same protections are not automatically transferred to the species and some exceptions may apply. See http://www.fws.gov/endangered/esa-library/pdf/t-vs-e.pdf or http://oceanservice.noaa.gov/facts/endangered.html for more information.

Q: What are the possible negative aspects of listing pintos as endangered?

A: Although ESA listing provides heightened protection and awareness, some people may not value a particular species and wonder why the federal government is putting funds towards a species they may find frivolous. In addition, conducting research on endangered species requires a lengthy permitting process that may be out of sync with funding cycles. This is an added level of difficulty but at the same time it is essential to have in place to help ensure the best possible research and ensure immediate relaying of research findings to NOAA Protected Resources to enable species restoration.

Q: What is your opinion on pinto abalone listing? Should they be listed as endangered or threatened?

A: That is a good question. In California and Washington, stocks are dangerously low. In British Columbia, Canada the Species at Risk Act already protects the pinto abalone and stocks in Alaska, USA have declined in recent years. I’ll have to reserve judgment until I see all of the data.

Q: In your experience, is it worth it to list abalones as endangered?

A: Absolutely! These species are really at the brink of extinction largely due to human activities (such as fishing) and I strongly believe that it is our responsibility as stewards of our planet (as corny as it sounds) to try and repair any damage we have caused.

Feel free to post additional questions for me or Carolyn!

For additional information on abalone, please see my post here.

Friday Funny

A little Friday afternoon science inspiration!

Willow the (White) Whale

An all white humpback whale was sighted off the coast of Norway earlier this week. It is believed that only 2 other “all white” humpbacks have been observed. British maritime engineer Dan Fisher named this particular whale Willow the Whale.

Twins! (kinda)

Why is this humpback all white? Willow has a condition called leucism, which causes a reduction in all skin pigments. How is leucism different from albinism you may ask? Albinism only effects the production of melanin, while leucism prevents formation of all pigments. Many are calling Willow Moby Dick’s doppelganger, although Moby Dick was supposed to be a sperm whale.

So why are we so fascinated with albinism and leucism?

Leucistic Penguin

Many leucistic animals have been found, including penguins, orcas, alligators, snakes, birds, axolotls and lions. I find these animals interesting because they seem to be evolutionarily less fit for their environment due to their stark white color. How does an all white snake camouflage itself from a predator? I imagine this is less of an issue for whales and lions. Some folk tales attribute magical powers to albino animals, and there is even an urban myth about albino alligators in New York sewers.

Why do you find albino & leucistic animals interesting?

Video of Willow

Video of all white orca

Jelly Blooms: Too Much of a Good Thing?

Photo by Randy Wilder, copyright Monterey Bay Aquarium

Last summer I attended the Marine Invertebrate Zoology course at Friday Harbor Labs (FHL) on San Juan Island. I was lucky enough to meet Claudia Mills, “the grand duchess of jellyfish”, and a recent article published by KCTS 9 about Claudia got me thinking about one of my favorite topics- jelly blooms.

My second tweet ever! Claudia helped us ID an egg yolk jelly

Claudia has been observing jelly populations off the docks of Friday Harbor Labs for the past 35 years. She has observed a decrease in the number of jellies, but is still finding the same diversity of jellies. This was surprising, given the increased press over the years about “alien”  jellies “taking over the oceans” with their “slime” as jelly blooms apparently increase.

What is a jelly bloom?

A jelly bloom happens when a very large number of jellies appear in the same place. They often occur where two ocean currents collide. Jelly blooms usually last for a short period of time, but in some cases can last multiple years.

What causes a jelly bloom?

There have been many hypotheses for what can cause jelly blooms, such as overfishing, ocean warming, ocean acidification, pollution, algal blooms and recently “ocean sprawl” in the recent Frontiers in Ecology article. Research suggests that jellyfish will opportunistically fill the niche that is usually occupied by fish in a healthy ocean ecosystem when the ecosystem degrades due to pollution, acidification or other factors. Richardson et al. provides a good review of possible causes of jelly blooms in this article. Another possibility is “shifting baselines”. Because we don’t have historical data to compare today’s jelly populations with, it appears that jelly blooms are increasing.

Jelly Blooms in the Media

The media has often sensationalized jelly blooms by citing them as “invasions” and “attacks” like this BBC article, and even citing jelly blooms as evidence that “the meek are indeed inheriting the earth” in this OnEarth article (insulting!).  On Claudia’s website she says that the summary of this OnEarth article “…states ‘Swarms of jellyfish are invading coasts around the world. It’s an epidemic, and it’s coming soon to a beach near you’  in spite of my cautions that this may not be strictly true.’ ” Claudia isn’t the only scientist who isn’t sure that jellyfish are on the rise- Claudia is a part of the research group Jellyfish Data Initiative (JEDI). JEDI published an article in BioScience in February 2012 after compiling 500,000 records of data to examine patterns in jelly blooms stating findings that suggest 20-year cycles in jelly populations, as opposed to increased jelly blooms worldwide.

It is true that jelly blooms can be problematic. Jellies can clog water intake pipes and fishing nets and cause costly damages. In order to definitively say that ocean degradation is the cause of jelly blooms and that jelly blooms are increasing worldwide, more research is needed. Not all jelly populations behave the same- some populations of jellies have declined such as Spirocodon and Polyorchis penicillatus due to habitat loss.

Nomura “infestation” in Japan. Copyright: Shin-ichi Uye, Hiroshima University

Jelly trivia!

Q: What is a group of jellies called?

A: A smack!

I long for the day when I can say “Hey, I just saw a smack of jellies!”.

I would like to think that if the oceans were overtaken in the future by giant jellies in some crazy scifi movie way, that I would respect our jelly overlords. Maybe its karma for most people seeing invertebrates as meek, boring and primitive…

Jelly invasion!!!

Interesting Links:

Listen to NPR story “Jellyfish Take Over an Over-Fished Area”

National Geographic Jelly Pictures

What are abalone and why are they so awesome?

When I tell people that I work with abalone I get one of two reactions: “Oh cool…” followed by a slow head nod (a.k.a. they have no idea what abalone are) or “Oh I ate that once!”. So I thought it would be a good idea to do an informative blog post on abalone for y’all’s (is that a word?) education. If you are like most people, you have seen abalone in one of two ways:

 

 

 

 

Hopefully, after you read this post you will have a new found appreciation for abalone.

What are abalone?

Abalone are marine gastropod molluscs, which means they are marine snails. There are 7 species on the West Coast, and about 60-100 species recognized globally. I will focus on the 7 species found on the West Coast: pinto abalone (also known as Northern abalone), black, white, pink, red, green, and threaded.

My work in the Friedman lab focuses on pinto abalone restoration and development of new tagging methods for abalone (see my manuscript on tagging here). The Friedman lab also has black and red abalone. If you would like to learn more about the Pinto Abalone restoration project in Washington, go here or watch the video here. For current information (November 2013) on Pinto abalone status in Washington State, see my post here.

What does an abalone look like?

Abalone are single shelled snails with a large muscular foot to hold them to rocks. The basic external anatomy of an abalone includes a shell with respiratory pores and apex, foot muscle, head with cephalic tentacles and eyes, and epipodial tissue surrounding the shell. Respiratory pores are used for reproduction, waste elimination, and breathing.

 

 

 

The most important external structures on abalone to recognize for species identification are the number of open respiratory pores, shell shape and color, size, and epipodial tissue and tentacle color. Abalone have a relatively flat shell with a spiral shaped top, called the apex. When viewing abalone from above, with their back end facing you (the apex), the respiratory pores run along the left side. Often times the mantle tissue covers the inside of the pores, giving them color inside. Depending on the species, they can be raised or even with their shell.

Abalone have two larger tentacles that come off their head, called the cephalic tentacles. They also have many smaller tentacles called the epipodial tentacles all around their shell. The cephalic tentacles are much thicker and often longer than the smaller epipodial tentacles. Different  abalone species have varying coloration of their tentacles, so this can be a good external way to identify the species. Along the edge of their shell, depending on the animal, a ring of tissue can be seen, called the epipodial tissue where the epipodial tentacles attach to the body. Depending on the species this tissue can be a variety of colors and textures. Abalone shells can also be a variety of shapes and textures. Some are bumpy and have ridges, like pinto abalone, others are very smooth, like the black abalone.

Side view of Juvenile Pinto Abalone

What does a day in the life of an abalone look like?

Abalone eat diatoms and microalgae as juveniles and macroalgae as young adults and adults, like bull kelp, turkish towel, dulse, and laminaria. They use their specialized zipper like “tongue” to scrape algae. When they aren’t eating, they spend most of their time hunkered down in “home scars” on or under rocks to avoid being eaten. Their most common predators are sea otters and the sun star Pycnopodia (Pycno). See a video of a juvenile abalone escaping a pycno here. Abalone are either male or female, and when they reproduce they broadcast spawn like many invertebrates. They release their gametes through their respiratory pores.

A face only a mother could love. Or an abalone biologist.

Why do I think abalone are cool?

One of my favorite things about my job is watching abalone behaviors. While it may seem boring watching a snail, these guys are really cool! They can be very active, especially when eating or escaping predators. When they sense a predator, they sometimes show a behavior called “torsion”, where they twist their shell around, attempting to remove whatever predator is touching their shell. Then, often times, they get up and move! They move a lot faster than you would think (see video above). They also show fun behaviors during feeding. They will reach out parts of their foot muscle to grasp at pieces of algae. I also find their eyes very interesting- I get a sense of their personality. That may sound silly since abalone don’t have brains, they have a cerebral ganglion and are often considered “primitive”. I think their behaviors are what sets them apart from other marine snails and they are a very unique species.

Why are abalone important?

Other than consumption and jewelry production, abalone are important culturally and ecologically. Culturally they are important because many Native tribes on the West Coast have harvested abalone for their meat and shells. Ecologically, they maintain habitat. Urchins and abalone are believed to preform similar ecological functions by controlling algal density. It is hard to justify why it is important to prevent the extinction of certain animals, as it is difficult to assign “worth” to a species, other than economically or culturally. However, I do know that I would like future generations to be able to enjoy this unique animal, and we can only do that if this species is able to rebound globally.

Abalone Facts

-Abalone have gills! They have two gills internally, close to their respiratory pores

-It is correct to say either “abalone” or “abalones” when talking about multiple abalone

And an answer to a common question: No, I have not eaten abalone. The recreational harvest of pinto abalone has been illegal in Washington since 1994. It is also illegal to harvest abalone in California with SCUBA, and free divers are limited in the number of abalone they can take. Since 1969, abalone populations have declined globally more than 50% (FAO, Fisheries and Aquaculture, 2008), with many species now recognized as threatened, endangered, or species of concern. I personally don’t eat abalone, just in case someone isn’t being truthful about the origin of the animal, as the sale of abalone on the black market is pretty common.

Please let me know if you have question or corrections! I will do my best to address them.

Filter Friends!

I get to play with all sorts of cool animals for my job, some by accident. One of my responsibilities is to change the filters at the abalone hatchery located at the NOAA Mukilteo facility. This is where I find all sorts of cool stuff! Take a look at my favorites:

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Not pictured include a kelp crab, lots of hooded nudibranchs, the nudibranch Hermissenda crassicornis, brittle stars, green urchins, scallops, lots of snails, and some polychaetes. Enjoy! More to come.

Can anyone could help me ID those sea stars?