Category Archives: Shellfish

With caution, one can avoid the risk of illness when gathering shellfish

If you are planning to gather some shellfish to eat over Labor Day weekend — or anytime for that matter — state health officials urge you to follow the “three Cs” of shellfish — check, chill and cook.

The state’s Shellfish Safety Map shows areas open and closed to harvesting.
Map: Washington State Dept. of Health

At least 10 cases of an intestinal illness called vibriosis have been reported this year to the Washington State Department of Health, all resulting from people picking oysters themselves and eating them raw or undercooked. The disease is caused by a bacteria, Vibrio parahaemolyticus, an organism that occurs naturally and thrives in warm temperatures.

“The shellfish industry follows special control measures during the summer months to keep people who choose to eat raw oysters from getting sick,” said Rick Porso, director of the Office of Environmental Health and Safety, in a news release. “For those who enjoy collecting and consuming their own shellfish, it’s important that they follow a few simple measures to stay healthy.”

The combination of warm weather, lack of rain and low tides all contribute to the growth of bacteria in oysters growing on the beach.

The state Department of Health uses the “three Cs” as a reminder for recreational shellfish harvesters as well as people who gather shellfish from their own beaches:

  • CHECK: Before heading to the beach, make sure that shellfish in the area are safe to eat. The Shellfish Safety Map, updated daily, will tell you where it is safe to gather shellfish. At the moment, many areas are closed because of paralytic shellfish poison produced by a type of plankton. Unlike Vibrio, PSP cannot be destroyed by cooking.
  • CHILL: Gather shellfish as the tide goes out, so they are not allowed to sit for long in the sun. Put them on ice immediately or get them into a refrigerator.
  • COOK: Cooking at 145 degrees F. for at least 15 seconds should destroy Vibrio bacteria, health officials say. It is not enough to cook them until their shells open.

Symptoms of vibriosis include diarrhea, abdominal cramps, nausea, vomiting, headache, fever and chills. The illness usually runs its course in two to three days. For information see “Vibriosis” on the Department of Health’s website.

Symptoms of paralytic shellfish poisoning usually begin with tingling of the lips and tongue, progressing to numbness in fingers and toes followed by loss of control over arms and legs and difficulty breathing. Nausea and vomiting may occur. PSP can be a life-threatening condition, so victims should seek medical help immediately. For information, see “Paralytic shellfish poison” on the Department of Health’s website.

Besides health advisories, the Shellfish Safety Map mentioned above also includes the water-quality classification, a link to shellfish seasons to determine whether a beach is legally open along with other information,

Amusing Monday: A quiz for you based on the ‘Puget Sound Fact Book’

Two years ago, I worked with a group of Puget Sound researchers and environmental writers to produce the “Puget Sound Fact Book” (PDF 27.6 mb) for the Encyclopedia of Puget Sound and Puget Sound Institute. The project was funded by the Environmental Protection Agency to provide a quick reference for anyone interested in the Puget Sound ecosystem.

I have pulled out some of the facts (with excerpts from the fact book) to create a 15-question quiz for this “Amusing Monday” feature. The answers and quotes from the book can be found below the quiz.

1. Puget Sound averages 205 feet deep. What is its greatest depth?

A. 300 feet
B. 600 feet
C. 900 feet
D. 1,200 feet

2. It is said that Puget Sound was carved out by a series of glaciers. What was the name of the last ice glaciation some 15,000 years ago?

A. Vashon
B. Cascade
C. Blake
D. Olympia

3. One river is responsible for at least one-third of all the freshwater flowing into Puget Sound. What river is it?

A. Snohomish
B. Skagit
C. Skokomish
D. Puyallup

4. How much water is contained in the main basin of Puget Sound, which includes all of the inlets south of Whidbey Island?

A. 5 cubic miles
B. 10 cubic miles
C. 40 cubic miles
D. 80 cubic miles

5. How many Washington counties have shorelines that front on Puget Sound, including the Strait of Juan de Fuca and waters around the San Juan Island? (That’s the definition of Puget Sound used by the Puget Sound Partnership.)

A. Six
B. Eight
C. Ten
D. Twelve

6. What percentage of the total Washington state population lives in counties with shorelines on Puget Sound?

A. 58 percent
B. 68 percent
C. 78 percent
D. 88 percent

7. Puget Sound is part of the Salish Sea, which extends into Canada. How many marine mammals are considered by researchers to be “highly dependent” on habitats in the Salish Sea?

A. 10
B. 20
C. 30
D. 40

8. Three types of killer whales spend their lives in and around the Salish Sea. “Residents” specialize in eating chinook salmon, and “transients” specialize in eating marine mammals. What do the so-called “offshore” killer whales specialize in eating?

A. Sharks
B. Squid
C. Plankton
D. Birds

9. Rockfish are a long-lived species that live in rocky areas of Puget Sound. How many species of rockfish can found in the waterway?

A. Four
B. 12
C. 21
D. 28

10. What is the length of shoreline in the main basin of Puget Sound, which includes all inlets south of Whidbey Island?

A. 246 miles
B. 522 miles
C. 890 miles
D. 1,332 miles

11. Bulkheads and other shoreline armoring disrupt the ecological functions of natural shorelines. What percentage of the Puget Sound shoreline is armored with man-made structures?

A. 7 percent
B. 17 percent
C. 27 percent
D. 37 percent

12. How many dams could be counted in 2006 in the greater Puget Sound region, including the Elwha dams on the Olympic Peninsula?

A. 136
B. 236
C. 336
D. 436

13. Puget Sound Partnership tracks the attitudes and values of Puget Sound residents. What percentage of the population believes that cleaning up the waters of Puget Sound is an “urgent” priority?

A. 40 percent
B. 50 percent
C. 60 percent
D. 70 percent

14. Climate change can be expected to result in significant changes in the Puget Sound region. Which of the following is something we are likely to see over the next 40 years?

A. Higher 24-hour rainfall totals
B. Higher peak flows in streams with more flooding
C. Α small change in annual rainfall totals
D. All of the above

15. Climate change also affects sea life through ocean acidification. Few species in seawater are expected to avoid impacts. Some of the greatest concerns are being expressed for which animals?

A. Shellfish
B. Sharks
C. Salmon
D. Sea lions

Answers:

1. Puget Sound averages 205 feet deep. What is its greatest depth? Answer: C, 900 feet

“Puget Sound averages 205 feet deep, with the deepest spot near Point Jefferson in Kitsap County at more than 900 feet.”

2. It is said that Puget Sound was carved out by a series of glaciers. What was the name of the last ice glaciation some 15,000 years ago? Answer: A, Vashon

“Puget Sound, as we know it today, owes much of its size and shape to massive ice sheets that periodically advanced from the north, gouging out deep grooves in the landscape. The most recent glacier advance, about 15,000 years ago, reached its fingers beyond Olympia. The ice sheet, known as the Vashon glacier, was more than a half-mile thick in Central Puget Sound and nearly a mile thick at the Canadian border.”

3. One river is responsible for at least one-third of all the freshwater flowing into Puget Sound. What river is it? Answer: B, Skagit

“The annual average river flow into the Sound is about 1,174 cubic meters per second, and a third to a half of this comes from the Skagit River flowing into Whidbey Basin. It would take about 5 years for all the rivers flowing into the Sound to fill up its volume … “

4. How much water is contained in the main basin of Puget Sound, which includes all of the inlets south of Whidbey Island? Answer: C, 40 cubic miles

“Chesapeake Bay, which filled the immense valley of an ancient Susquehanna River, covers about 4,480 square miles — more than four times the area of Puget Sound (not including waters north of Whidbey Island). But Chesapeake Bay is shallow — averaging just 21 feet deep. In comparison, Puget Sound averages 205 feet deep… Consequently, Puget Sound can hold a more massive volume of water — some 40 cubic miles, well beyond Chesapeake Bay’s volume of 18 cubic miles.”

5. How many Washington counties have shorelines that front on Puget Sound, including the Strait of Juan de Fuca and waters around the San Juan Island? (That’s the definition of Puget Sound used by the Puget Sound Partnership.) Answer: D, twelve

“The Puget Sound coastal shoreline lies within 12 of Washington state’s 39 counties: Clallam, Island, Jefferson, King, Kitsap, Mason, Pierce, San Juan, Skagit, Snohomish, Thurston and Whatcom. An additional two counties (Lewis County and Grays Harbor County) are also within the watershed basin, although they do not have Puget Sound coastal shorelines….”

6. What percentage of the total Washington state population lives in counties with shorelines on Puget Sound? Answer: B, 68 percent

“As of 2014, the 12 Puget Sound coastal shoreline counties accounted for 68 percent of the Washington State population — 4,779,172 out of 7,061,530, according to the U.S. Census Bureau.”

7. Puget Sound is part of the Salish Sea, which extends into Canada. How many marine mammals are considered by researchers to be “highly dependent” on habitats in the Salish Sea? Answer: C, 30 marine mammals

“Thirty-eight species of mammals depend on the Salish Sea. Of the 38 species of mammals that have been documented using the Salish Sea marine ecosystem, 30 are highly dependent, 4 are moderately dependent, and 4 have a low dependence on the marine or intertidal habitat and marine derived food when present.”

8. Three types of killer whales spend their lives in and around the Salish Sea. “Residents” specialize in eating chinook salmon, and “transients” specialize in eating marine mammals. What do the so-called “offshore” killer whales specialize in eating? Answer: A, sharks

“Three ecotypes of killer whales (Orcinus orca) can be found in the Salish Sea. These distinct population segments or designatable units are classified as fish-eating Residents (both the Northern and Southern Resident populations), marine-mammal-eating transients (West Coast Transients), and fish eaters that specialize in sharks called Offshore Killer Whales.”

9. Rockfish are a long-lived species that live in rocky areas of Puget Sound. How many species of rockfish can found in the waterway? Answer: D, 28 species

“The Puget Sound has 28 species of rockfish. Rockfish are known to be some of the longest lived fish of Puget Sound. Maximum ages for several species are greater than 50 years. The rougheye rockfish can live up to 205 years.”

10. What is the length of shoreline in the main basin of Puget Sound, which includes all inlets south of Whidbey Island? Answer: D, 1,332 miles

“The coastline around Puget Sound is 2,143 km (1,332 miles) long. It would take about 18 unceasing days and nights to walk the entire shoreline if it were passable — or legal — everywhere. Note: this distance refers to Puget Sound proper and does not include the San Juan Islands or the Strait of Juan de Fuca.”

11. Bulkheads and other shoreline armoring disrupt the ecological functions of natural shorelines. What percentage of the Puget Sound shoreline is armored with man-made structures? Answer: C, 27 percent armored

“The amount of artificial shoreline has increased by 3,443 percent since the mid- to late-1800s. For example, shoreline armoring — such as bulkheads and riprap — has been constructed on an average 27 percent of the Puget Sound shoreline, but as high as 63 percent of the central Puget Sound shoreline.”

12. How many dams could be counted in 2006 in the greater Puget Sound region, including the Elwha dams on the Olympic Peninsula? Answer: D, 436 dams

“As of 2006, there were 436 dams in the Puget Sound watershed. Dams alter the water flow of rivers and trap sediment, which affect deltas and embayments at the mouths of these rivers and streams. For example, there was nearly 19 million cubic meters of sediment trapped behind the Elwha and Glines Canyon Dams on the Elwha River ¬ enough sediment to fill a football field to the height of the Space Needle more than 19 times.”

13. Puget Sound Partnership tracks the attitudes and values of Puget Sound residents. What percentage of the population believes that cleaning up the waters of Puget Sound is an “urgent” priority? Answer: C, 60 percent

“A related, ongoing survey has been gauging the attitudes and values of individual Puget Sound residents, beginning with the first survey in 2008. Since the survey’s inception, more than 60 percent of the population has held to the belief that cleaning up the waters of Puget Sound is an ‘urgent’ priority.”

14. Climate change can be expected to result in significant changes in the Puget Sound region. Which of the following is something we are likely to see over the next 40 years? Answer: D, all of the above

“Projected changes in total annual precipitation are small (relative to variability) and show increases or decreases depending on models, which project a change of −2 % to +13 % for the 2050s (relative to 1970-1999) ….

“More rain in autumn will mean more severe storms and flooding. Annual peak 24-hour rainfall is projected to rise 4 to 30 percent (depending on greenhouse emissions levels) by the late 21st century. Hundred-year peak stream flows will rise 15 to 90 percent at 17 selected sites around Puget Sound. In the flood-prone Skagit Valley, the volume of the 100-year flood of the 2080s will surpass today’s by a quarter, and flooding and sea-level rise together will inundate 75 percent more area than flooding alone used to.

“At the other extreme, water will become scarcer in the spring and summer…. By the 2080s, average spring snowpack in the Puget Sound watershed is projected to decline 56 to 74 percent from levels 100 years earlier. The decline will reach 80 percent by the 2040s in the headwaters of the four rivers (the Tolt, Cedar, Green, and Sultan) serving the cities of Seattle, Tacoma, and Everett — reflecting the fact that their snowpacks are already very low, hence vulnerable. By the 2080s, April snowpack will largely disappear from all four watersheds, leaving Puget Sound’s major rivers low and dry in summer.”

15. Climate change also affects sea life through ocean acidification. Few species in seawater are expected to avoid impacts. Some of the greatest concerns are being expressed for which animals? Answer: A, shellfish

“Another factor has also made the Northwest a frontline for acidification: the importance of its shellfish industry, together with the special vulnerability of one key component, larval oysters. University of Washington researchers recently identified worrisome effects on other species with vital commercial or ecological importance. Acidification affects the ability of mussels to produce byssus, the tough adhesive threads that anchor them to their rocks against waves and surf — a life-and-death matter for a mussel. The native bay mussel (Mytilus trossulus) also loses byssal strength when water temperatures surpass 20 degrees C., whereas Mediterranean mussels (M. galloprovincialis) grow more byssus as the waters warm. This suggests a potential species succession, from native to introduced mussels, as Puget Sound becomes warmer and more acidic.

“Potentially more ecologically devastating are acidification’s effects on copepods and krill, small swimming crustaceans at the base of the marine food web….. Krill also inhabit deeper, more acidic waters than copepods, compounding their exposure. Their loss would be grievous for the fishes, seabirds and whales that depend on them.”

Are we at a crossroads in the green crab invasion on Dungeness Spit?

State biologists are holding out hope that the European green crab invasion at Dungeness Spit can be contained. We may now be going through a critical period, which could result in a permanent infestation or possibly the final throes of the invasion.

Green crabs, an invasive species known to displace native species and cause economic devastation to shellfish growers, were first discovered on April 12 in a marshy area on Graveyard Spit, which juts off from the larger Dungeness Spit in the Strait of Juan de Fuca.

The total number of green crabs caught in an ongoing intensive trapping program has reached 76. The weekly numbers have been declining, as shown in a chart on this page. That could be a good sign, but biologists are quite reserved in their predictions.

“The numbers are tapering off,” said Allen Pleus, coordinator of the state’s Aquatic Invasive Species Program, “but in my view the numbers are still too high. Eradication would take several weeks of zero. At this point, our main objective is to bring down the population to a point where spawning would not be successful.”

So far, all of the crabs caught are young and small — about 1 to 2.5 inches across their backs. This means that they have not been in the area for long, probably arriving on last year’s currents in the Strait of Juan de Fuca.

Another good sign is that no other crabs have been caught elsewhere along the Strait, although officials acknowledge that they would like to deploy more traps to capture any early invaders. Also, I am happy to report that no new crabs have been captured this year in Padilla Bay or on San Juan Island, where the state’s first confirmed green crab invasion took place last year. See Water Ways, Sept. 24, 2016.

Update: I’ve been informed that one green crab was caught in April in Padilla Bay where others were caught last year.

The decline in captures at Dungeness Spit may be a sign that some of the crabs have entered their reproductive phase, a period when they don’t eat and so are not attracted to the baited traps. Males and females get together to mate after molting, a phase of development in which they shed their exoskeletons. The trapping effort has reduced the crab numbers and made it more difficult for reproductive males and females to find each other, but each female can produce hundreds of thousands of eggs — so even one successful mating could expand the invasion.

This small male crab is one of the 76 European green crabs caught in traps at Dungeness Spit. // Photo: Allen Pleus

Because the baited traps may not work at this time, officials are experimenting with substrate traps, which are pieces of plastic pipe ranging in size from a half-inch to 2 inches, Allen told me. Young crabs may seek shelter in the tubes. So far, no crabs have been captured that way.

Another idea yet to be tried is baiting traps with pheromones, which are sexual attractants that lure crabs looking for a mate. Allen said he also would like to experiment with electrical stimulation, in which an electrical current is discharged in the muddy substrate to drive crabs out of their burrows. With proper control, no permanent harm comes to them or other creatures in the vicinity, Allen said.

When it comes to controlling future crab invasions in Puget Sound, experts would like to know where the crab larvae are coming from. The leading suspect is a population of green crabs that appear to have settled into Sooke Inlet, just west of Victoria on Vancouver Island in Canada. It is also possible that the larvae drifted in from coastal waters in British Columbia, Washington or even Oregon or California. Experts hope that genetic tests of green crabs from the various locations can be used to identify where the crabs on Dungeness Spit originated.

Emily Grason of Washington Sea Grant coordinates a group of volunteers who monitor traps placed throughout Puget Sound with a goal of stopping the next invasion.

“The presence of green crab in Dungeness Bay, though unfortunate, offers a unique opportunity to test how effective the EDRR (Early Detection-Rapid Response) model is for intervening in a potential green crab invasion,” Emily wrote yesterday in a blog post on the Crab Team website.

“Generally speaking, invasive species are rarely noticed in a new spot until they have already become too abundant to eradicate,” she said. “Though 76 crabs at Dungeness Spit is more than we would ever like to see, the population hasn’t yet reached the numbers that are seen in areas of greatest infestation. And they are, as far as we know, still confined to a relatively small location….

“Preventing and managing biological invasions is similar to planning for a wild fire season: The best thing to do is prevent either invasions or wildfires from taking hold in the first place, but we know that some will occur despite our best efforts. It’s difficult to forecast exactly where, when or how severe they will be when they do pop up, and yet it’s imperative to respond quickly and aggressively as soon as they are detected.”

Emily added that we are fortunate in this area to have the tremendous support of volunteers, partners and beachgoers, all involved in the effort to prevent a permanent invasion of green crabs. Staff and volunteers at the Dungeness National Wildlife Refuge have been instrumental in placing and tending the traps placed in that area.

Amusing Monday: Human super powers and other oddball things

Humans have at least five super powers that few people know about, according to Mind Warehouse, a video producer with nearly 2 million subscribers on YouTube.

The one so-called “superpower” that intrigued me the most was the ability to distinguish warm water from cold water by sound alone. The super-powers video, found first on this page, challenges viewers to close their eyes and listen as someone pours two glasses of water — one hot and one cold.

According to the video segment, which begins at 2:34, between 80 and 90 percent of people who listen to the video can tell whether it is hot or cold water being poured into the glasses. It has something to do with bubbles, according to the video.

Continue reading

Green crab invaders settle in on Dungeness Spit, Olympic Peninsula

An invasion of the European green crab, which started last summer in northern Puget Sound, appears to be continuing this spring with 16 green crabs caught in traps at one location on Dungeness Spit near Sequim.

European green crab
Photo: Gregory C. Jensen, UW

The new findings are not entirely unexpected, given that invasive green crabs have established a viable population in Sooke Inlet at the southern end of Vancouver Island in Canada. From there, young crab larvae can move with the currents until they settle and grow into adult crabs. Last summer and fall, green crabs were found on San Juan Island and in Padilla Bay.

The big concern now is that a growing population of invasive crabs could spread quickly to other parts of Puget Sound, causing damage to commercial shellfish beds and disrupting the Puget Sound ecosystem.

“It knocks the wind out of your sails for sure,” said Emily Grason when I asked how she felt about the latest discovery. “You feel kind of powerless, and you want to get out there and start doing things.”

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Hope is alive for restoration of Puget Sound shellfish beds

Officials in Washington state’s Shellfish Program have identified a clear pathway to meet a state goal of restoring 10,800 net acres of shellfish beds to a harvestable condition by 2020.

The 10,800-acre target, established by the Puget Sound Partnership, was considered overly ambitious by many people when the goal was approved in 2011. Many still believe that the shellfish restoration effort will go down in flames, along with other goals, such as increasing chinook salmon and killer whale populations by 2020.

In reporting on the Shellfish Implementation Strategy, a document still under development, I’ve learned that the goal is within reach if enough of the ongoing recovery efforts around Puget Sound continue to make progress. Please check out my latest stories “Bringing the shellfish back” and “Closing in on the magic number in Samish Bay,” both published in the Encyclopedia of Puget Sound.

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Crab Team training will foster the upcoming hunt for green crab invaders

A European green crab invasion may be taking place in Puget Sound, and Washington Sea Grant intends to enhance its Crab Team this summer with more volunteers looking in more places than ever before.

The second European green crab identified in Puget Sound was found in Padilla Bay, where three others were later trapped.
Photo: Padilla Bay Reserve

Training is about to get underway, and anyone with an interest in furthering science while being exposed to the wonders of nature may participate. It’s not always good weather, but I’ve been inspired by the camaraderie I’ve witnessed among dedicated volunteers.

The work involves going out to one or more selected sites each month from April into September with a team of two to four other volunteers. It is helpful to have folks who can carry the crab traps, plastic bins and other equipment. For details, check out the Washington Sea Grant website.

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Invasive oyster drills react differently to predators than natives

Invasive saltwater snails, including dreaded oyster drills, seem to be far more leery of predators than native snails under certain conditions, according to a new study by Emily Grason, whose research earned her a doctoral degree from the University of Washington.

An invasive Atlantic oyster drill feeds on a young Pacific oyster. // Photo: Emily Grason

Why non-native snails in Puget Sound would run and hide while native species stand their ground remains an open question, but the difference in behavior might provide an opportunity to better control the invasive species.

Of course, snails don’t actually run, but I was surprised to learn that they can move quite rapidly to find hiding places when they believe they are under attack.

Like many marine animals, snails use chemical clues to figure out what is happening in their environment. For her experiments, Emily created a flow-through system with two plastic shoeboxes. Chemical clues were provided in the upstream bin, while the reaction of the snails was observed in the downstream bin.

The most dramatic difference between native and non-native snails seemed to be when ground-up snails were deposited in the upstream bin, simulating a chemical release caused by a crab or other predator breaking open snail shells and consuming the tender morsels inside.

Continue reading

More invasive crabs found; wider search will resume next spring

Padilla Bay, an extensive inlet east of Anacortes in North Puget Sound, could become known as an early stronghold of the invasive European Green crab, a species dreaded for the economic damage it has brought to other regions of the country.

Trapping sites for crabs (gray markers) during this week’s rapid assessment in Padilla Bay. The red markers show locations where invasive European green crabs were found.
Trapping sites for crabs (gray markers) during this week’s rapid assessment in Padilla Bay. Red markers show locations where three more invasive European green crabs were found.
Map: Washington Sea Grant

After one young green crab was found in Padilla Bay on Sept. 19 (Water Ways, Sept. 24), three more crabs were found during an extensive trapping effort this past week. All four crabs were captured at different locations in the bay. These four live crabs followed the finding of a single adult green crab in the San Juan Islands — the first-ever finding of green crabs anywhere in Puget Sound. (Water Ways, Sept. 15).

With these new findings in Padilla Bay, the goal of containing the crabs to one area has become a greater challenge. Emily Grason, who coordinates a volunteer crab-surveillance program for Washington Sea Grant, discusses the difficulty of putting out enough traps to cover the entire bay. Read her report on the fist day of trapping:

“Similar to our trip to San Juan Island, we are conducting extensive trapping in an effort to learn more about whether there are more green crabs in Padilla Bay. One difference, however, is scale. Padilla Bay is massive, and it’s hard to know exactly where to start. On San Juan Island, the muddy habitats where we thought crabs would do well are well-defined, and relatively limited. Padilla Bay, on the other hand, is one giant muddy habitat — well, not all of it, but certainly a huge portion. We could trap for weeks and still not cover all of the suitable habitat!”

In all, 192 traps were set up at 31 sites, covering about 20 miles of shoreline. The crab team was fortunate to work with the expert staff at the Padilla Bay National Estuarine Research Reserve, a group of folks who know the area well and had worked with shoreline owners to get approval for access.

Three of the four green crabs caught in Padilla Bay were young, probably washed into the bay during last winter’s warm currents, Emily said in her wrap-up report of the effort.

“All of the detections of European green crabs occurred on the east portion of the bay,” she wrote. “Though the sites varied somewhat in the type of habitat, all of the crabs were found relatively high on the shore, in high salt marsh pools, or within a few meters of the shore.

The first of four European green crabs found in Padilla Bay. Photo: Padilla Bay Reserve
The first of four European green crabs found in Padilla Bay.
Photo: Padilla Bay National Estuarine Reserve

“Padilla Bay has about 20 miles of shoreline, and, at last count in 2004, there were 143 acres of salt marsh habitat in the bay,” she continued.”These numbers suggest that there are a lot of places European green crabs could live in Padilla Bay, and protecting the bay from this global invader will undoubtedly require a cooperative effort.”

Yesterday, the response team held a conference call to discuss what to do next. Team members agreed that no more intensive trapping would take place this year, Sean McDonald of the University of Washington told me in an email.

Winter is a tough time to catch crabs. Low tides shift from daytime hours to nighttime hours, making trapping more difficult. Meanwhile, crabs tend to lose their appetite during winter months, so they are less likely to go into the traps to get food, experts say.

Researchers, shellfish growers and beach walkers are being asked to stay alert for the green crabs, not only in Padilla Bay but also in nearby Samish and Fidalgo bays.

The Legislature will need to provide funding to continue the citizen science volunteer monitoring program, which provided an early warning that green crabs had invaded Puget Sound. Whether the crabs will survive and in what numbers is something that demands more study and perhaps a major eradication effort.

Meanwhile, Washington Department of Fish and Wildlife would like to expand its overall Aquatic Invasive Species Program with additional efforts to prevent invaders from coming into Puget Sound. For information, check out my story on invasive species in the Encyclopedia of Puget Sound — specifically the section titled “Biofouling still mostly unregulated.”

Second invasive green crab discovered in northern Puget Sound

A second European green crab has been found in Puget Sound, this one in Padilla Bay — about 30 miles southeast of where the first one was discovered about three weeks ago.

A second European green crab has been found in Puget Sound, this one in Padilla Bay. Photo: Padilla Bay Reserve
A second European green crab has been found in Puget Sound, this one in Padilla Bay.
Photo: Padilla Bay National Estuarine Research Reserve

Green crabs are an invasive species known to devour a variety of native species and alter habitats where they have become established. Keeping green crabs out of Puget Sound has been a goal of state officials for years.

After the first green crab was caught in a volunteer trapping program three weeks ago, experts mounted an intensive trapping effort to see if other green crabs were in the area around Westcott Bay in the San Juan Islands. (Water Ways, Sept. 3). No live crabs were found, but one cast-off shell (molt) was discovered nearby (Water Ways, Sept. 15).

The second green crab was found by Glen Alexander of the Padilla Bay National Estuarine Research Reserve while overturning rocks with a group of students.

The latest find is a young female crab, 34 millimeters across, which may have grown from a larva dispersed last winter.

“We were relieved to find very little evidence of a larger population of invasive European green crab in Westcott Bay,” Emily Grason of Washington Sea Grant said in a news release (PDF 371 kb). “But finding an additional crab at a site more than 30 miles away suggests that ongoing vigilance is critical across all Puget Sound shorelines. WSG’s Crab Team is committed to continuing the efforts of volunteer monitoring as resources allow, but we also rely on beachgoers to keep a watchful eye out for this invasive species.”

A second rapid-response effort will get underway Monday with more traps being deployed over a larger area than last time. The goal is to locate any crabs that may have made a home in the area and determine where the crabs might be gaining a foothold.

The advice for beachgoers remains the same:

  1. Learn how to how to identify green crab. Check out the Crab Team webpage at wsg.washington.edu/crabteam or Facebook and Twitter @WAGreenCrab.
  2. Take a photo and report sightings to the WSG Crab team at crabteam@uw.edu.
  3. Shellfish collected in one location should never be released or “wet stored” in another location unless authorized by WDFW.
  4. Clean, drain and dry recreational gear or other materials after beach visits.

If you haven’t seen it, you may want to review a series I wrote on invasive species for the Encyclopedia of Puget Sound, including a story about green crabs and the volunteer monitoring program.