Category Archives: Shellfish

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 or Facebook and Twitter @WAGreenCrab.
  2. Take a photo and report sightings to the WSG Crab team at
  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.

No new green crabs have been found, but the search will go on

No European green crabs were caught this week during an intensive two-day trapping program designed to see if any of the invasive crabs have gained a foothold in the San Juan Islands.

These are the locations and number of traps placed on Monday in the northern San Juan Islands. Map: Washington Sea Grant
These are the locations and number of traps placed in the northern San Juan Islands on Monday. // Map: Washington Sea Grant

If you recall, a single adult green crab was trapped Aug. 31 by a team of volunteers in the San Juan Islands. It was the first green crab ever found in Puget Sound, but experts have been worried about the crab for years. (See Water Ways, Sept. 3.) The volunteers are involved in a citizen science monitoring program to locate green crabs when they first arrive in Puget Sound and before they become a breeding population.

The response by professional leaders of the Crab Team was to place 97 traps in and around the location where the first crab was found. The effort was started on Monday and repeated on Tuesday. The maps on this page show the locations and the number of traps place at site on the two days. Hundreds of native crabs were trapped and inspected, but no green crabs were found.

These are the locations and number of traps placed in the northern San Juan Islands on Tuesday. Map: Washington Sea Grant
These are the locations and number of traps placed in the northern San Juan Islands on Tuesday. // Map: Washington Sea Grant

Although no live crabs were found, one molt (cast-off shell) from a green crab was found by Jeff Adams, a marine ecologist for Washington Sea Grant who manages the Crab Team of volunteers. The molt was close to where the live crab was found. The experts have not determined if the molt came from the first crab or if there might be other crabs in the area.

The next step is still being planned. It could involve another intensive trapping effort, perhaps in the spring, as well as increasing the number of volunteer trapping sites in the San Juan Islands. The volunteer program takes a hiatus in the winter, when the crabs are less active, but it will resume in the spring.

The next green crab training program is scheduled for March, when new and former citizen science volunteers will be taught how to identify green crabs and conduct an effective trapping effort in up to 30 locations throughout Puget Sound. To learn more about the volunteer program, check the Washington Sea Grant webpage “Get Involved” or sign up for a free email newsletter called “Crab Team News” (click “Newsletters”).

Emily Grason, Crab Team coordinator for Washington Sea Grant, was involved in the two-day intensive trapping program. Emily blogs about the effort on the Crab Team website:

You may want to review my recent writing project on invasive species for the Encyclopedia of Puget Sound, including a story about green crabs and the volunteer monitoring program.

Sean McDonald of Washington Sea Grant heads out to check on crab traps on Henry Island, not far from where the first green crab was found in Puget Sound. Photo: Emily Grason, WSG
Sean McDonald of Washington Sea Grant heads out to check on crab traps on Henry Island, not far from where the first green crab was found in Puget Sound. // Photo: Emily Grason, WSG

A single green crab invader has been found, the first in Puget Sound

A European green crab, one of the most dreaded invasive species in the world, has finally arrived in Puget Sound.

Caught in a crab trap on San Juan Island were these animals — including the first European green crab ever found in Puget Sound. Photo: Photo Craig Staude, courtesy of Washington Sea Grant
Caught in a crab trap on San Juan Island were these fish, along with the first European green crab ever found in Puget Sound.
Photo: Craig Staude, courtesy of Washington Sea Grant

A single adult green crab was caught in a trap deployed on San Juan Island by a team of volunteers involved in a regionwide effort to locate the invasive crabs before they become an established population.

Until now, green crabs have never been found in Puget Sound, although they have managed to establish breeding populations along the West Coast — including Willapa Bay and Grays Harbor in Washington and the western side of Vancouver Island in British Columbia.

Coincidentally, I recently completed a writing project on invasive species for the Encyclopedia of Puget Sound, including a story about green crabs and the volunteer monitoring program.

Here’s what I wrote: “Puget Sound has so far avoided an invasion of European green crabs — at least none have been found — but the threat could be just around the corner….

“Green crabs are but one of the invasive species threatening Washington state, but they are getting special attention because of fears they could seriously affect the economy and ecosystem of Puget Sound. Besides devouring young native crabs and shellfish, they compete for food with a variety of species, including fish and birds.”

Along the beach, careful observers can often find crab molts. The green crab, upper left, can be distinguished by the points on its carapace. Photo: Jeff Adams, Washington Sea Grant
Along the beach, careful observers may find weathered crab molts of all sizes. The green crab, upper left, can be distinguished by the five points on each side of the carapace. (Click to enlarge.)
Photo: Jeff Adams, Washington Sea Grant

In Canada, one breeding population has been identified in Sooke Inlet near the southernmost tip of Vancouver Island. That’s about 40 miles away from Westcott Bay, where Puget Sound’s first green crab was found on Tuesday.

It is likely that the crab traveled to San Juan Island in its early free-swimming larval form by drifting with the currents, said Jeff Adams, a marine ecologist for Washington Sea Grant who manages the Crab Team of volunteers. This crab likely settled down in suitable habitat and located enough food to grow into an adult. Based on the crab’s size, it probably arrived last year, Jeff told me.

European green crab Photo: Gregory C. Jensen, UW
European green crab // Photo: Gregory Jensen, UW

Finding a green crab in Puget Sound is alarming, Jeff said, but it is a good sign that the first crab was found by the volunteer monitors. That suggests that the trapping program is working. If this first crab turns out to be a single individual without a mate, then the threat would die out, at least for now.

The concern is that if one crab can survive in Puget Sound, then others may also be lurking around, increasing the chance of male-female pairing. The next step is to conduct a more extensive trapping effort in the area where the first green crab was found, then branch out to other suitable habitats in the San Juan Islands, Jeff said. The expanded effort is planned for the week of Sept. 11 and will include a search for molts — the shells left behind when crabs outgrow their exoskeletons and enter a new stage of growth.

Green crab
Green crab

Researchers and others who work with invasive species quickly recovered from their initial surprise at finding a green crab in Puget Sound, then got down to business in planning how to survey for crabs and manage their potential impacts.

Allen Pleus, coordinator of the Aquatic Invasive Species Program at the Washington Department of Fish and Wildlife, told me several weeks ago that if green crabs show up in Puget Sound, one idea would be to conduct an extensive trapping program to eradicate or at least reduce their population. First, however, the extent of the infestation must be identified. I expect that more extensive trapping will be planned next spring and summer to look for offspring from any successful mating in the San Juan Islands.

This video shows a green crab found in Willapa Bay on the Washington Coast.

Typically, green crabs are found in marshy areas, which are habitats extensively used by our native hairy shore crab. But Jeff tells me that some populations of green crabs seem to be expanding their habitat into more exposed rocky areas.

With roughly 400 suitable sites for the crabs in Puget Sound, invasive species experts are calling for everyone who visits a beach to look for green crabs and their molts. One can learn to identify green crabs from the Washington Sea Grant website. The volunteer trapping program is funded by the Environmental Protection Agency with a grant to Fish and Wildlife.

A public discussion about green crabs and how people can help protect Puget Sound from an invasion is scheduled for Sept. 13 at Friday Harbor Laboratories on San Juan Island. See Crab Team Public Presentation.

Invasive species hitching a ride into Puget Sound

We hear about the “balance of nature,” but it’s not something that we can truly understand until the balance is thrown out of whack by something like climate change or invasive species.

Until I began a recent reporting project for Puget Sound Institute, I never realized that San Francisco Bay was such a hotbed of invasive species. Beginning with the California Gold Rush, ships began moving in and out of the bay in unbelievable numbers, arriving from ports all around the world. Now, more than 200 non-native species are making their permanent home in the bay — including some species that have thoroughly altered the local ecosystem.

So far, we have been lucky in Puget Sound. Experts say we have about 75 firmly established non-native species, yet none of them have created the widespread damage caused in San Francisco Bay by European green crabs and Asian clams or in the Great Lakes by zebra mussels. The video on this page does a good job of telling the Great Lakes story, which has been repeated all over the world.

Once people in Washington state realized how disruptive invasive species can be, the struggle was on to protect Puget Sound from alien invaders — particularly those found in San Francisco Bay, which is just a short hop away on the world scale. My series of stories talks about concerns for Puget Sound and the efforts to control a possible invasion.

Three weeks ago in Water Ways, I described legislation that would reduce state and federal controls over invasive species. See “Bill could increase risks of alien species invasions in Puget Sound waters.”

On the East Coast, where they are native, striped bass are one of the most popular sport fish. Here, Angela Anning of Connecticut shows off her impressive striper. On the West Coast, striped bass could be considered an invasive species. Photo: NOAA
On the East Coast, where they are native, striped bass are one of the most popular sport fish. Here, Angela Anning of Connecticut shows off her impressive striper. On the West Coast, striped bass could be considered an invasive species.
Photo: NOAA

Invasive species range in size from microscopic viruses to four-foot-long striped bass. In California, the striped bass became a prized sport fish after it was intentionally introduced in 1879. But over the past decade concerns have grown for their effects on the salmon population. The jury is still out on whether high numbers of stripers should be sustained for anglers or the population should be fished down rapidly to save salmon and other species. Check out these stories:

Meanwhile, striped bass have been moving up the West Coast, possibly because of warmer waters due to climate change. A few years ago, a 55-pounder was caught in the Columbia River, and I’ve heard rumors that they have been seen in the Strait of Juan de Fuca.

On the small side, I report on a tiny crustacean, an invasive copepod that has almost entirely displaced native copepods in Samish Bay in northern Puget Sound. Copepods are important prey for small fish, including herring, which feed the larger salmon. The invasive copepods are smaller and more difficult for fish to see, which could have a cascading effect on the entire food web.

Invasive copepod Oithona davisae under magnification Photo: Jeff Cordell, University of Washington
Invasive copepod Oithona davisae
Photo: Jeff Cordell, UW

A major concern for Puget Sound biologists is the European green crab, which could move into Puget Sound from San Francisco Bay in ballast water or with warm ocean currents during an El Niño year, like the one just past. As I describe in the new series, a major program involving citizen science volunteers is ongoing in a search to find the first green crabs before they gain a foothold.

Pacific oysters, another non-native species, were intentionally brought to the Northwest from Japan in the early 1900s to replace the native Olympia oyster, which had been decimated by poor water quality. Pacific oysters soon became a mainstay of the shellfish industry in the Puget Sound region and are now growing thick in numerous areas.

European green crab Photo: Washington Sea Grant
European green crab
Photo: Gregory C. Jensen, UW

Similar introductions of Pacific oysters occurred in California beginning more than 100 years ago, but for some reason the oyster populations never took hold, according to a report in the publication California Fish and Game (PDF 1.7 mb). Finally, in the early 2000s, the invasion began to take off.

“It remains unclear why there should be a successful invasion now, given the failure of previous attempts to deliberately introduce the species both locally and throughout California…,” the report says.

“If populations in Southern California waters do continue to expand and grow, as they have in other areas where they have invaded, it will undoubtedly bring changes to the way our estuarine intertidal habitats function as well as in the way we must manage them.

Pacific oyster Photo: Washington Sea Grant
Pacific oyster
Photo: Washington Sea Grant

“Because Pacific oysters rapidly reach large sizes, they could pose problems related to fouling of maritime equipment, infrastructure, and vessels,” the report continues. “Pacific oysters stand out as one of the most transformative invaders of marine ecosystems.”

As Washington state takes steps to keep alien species from invading Puget Sound from California, California officials may adopt similar measures to block invaders from coming into that state.

Please take a look at this package of stories I wrote for Puget Sound Institute, with editing by Jeff Rice and design by Kris Symer:

The proper use of crab pots means extra crabs for the dinner plate

“Catch more crab!”

This is a campaign slogan going out to Puget Sound crabbers. It is a positive message, built upon the goals of:

  • Helping people avoid losing their crab pots,
  • Reducing the number of crabs that go to waste, and
  • Increasing the number of crabs available for harvest.


We’ve talked about the problems of lost crab pots that keep on catching crabs on the bottom of Puget Sound. About 12,000 crab pots are lost each year in Puget Sound, killing an estimated 178,000 legal-sized Dungeness crabs that would otherwise be served up for dinner. In January, I described some simple alterations to crab pots that allow crabs to escape when a pot gets lost. See Water Ways, Jan. 28.

Even more basic, however, are proven techniques that help people select equipment and place their crab pots so they don’t get damaged or lost in the first place.

The Northwest Straits Initiative, authorized by Congress in 1998, has been working on the problem of derelict gear for years, including the retrieval of thousands of lost nets and crab pots from Puget Sound. When it came to enlisting the public’s help in prevention, campaign organizers realized that everyone was on the same side, said Jason Morgan of the nonprofit Northwest Straits Foundation.


“We previously focused on the doom and gloom of it, talking about so many crabs killed each year,” Jason told me.

Working with sociologists, campaign organizers realized that “the better way to reach people is not to talk about dead crabs but to say we want you to catch more crabs and keep your crab pots.”

The Northwest Straits Foundation has developed a three-year plan of action, including education for the public; improved communication among crabbers, vessel operators and government officials; and recommendations for improving regulations.

The plan was put together by a working group of 35 people involved in various aspects of crab harvesting, boat traffic and resource protection.

“It was a great collaborative process,” Jason said. “There was no butting of heads or anything like that.”

The “Puget Sound Lost Crab Pot Prevention Plan” (PDF 996 kb) states:

“Crab pots are lost for a variety of reasons. Causes for loss generally fall into three categories:

  • Vessel interaction (both recreational and commercial vessels);
  • Improperly configured gear, including improperly tied knots; and
  • Improperly placed gear.

“All these categories usually include a degree of user error, either on the part of the crabber, or on the part of the boater or vessel operator.”

The plan includes at least 25 strategies for reducing conflicts between vessel traffic and crab pots, reducing tampering and sabotage, improving crabbing equipment and pot configuration, and removing abandoned crab pots during non-crabbing days.

One of the interesting ideas is to require online registration for recreational crab endorsements on fishing licenses. Applicants would take a short quiz to make sure they know the rules.

Rich Childers, shellfish manager for Washington Department of Fish and Wildlife, said the various regulatory proposals in the plan are under advisement. One idea, which has proven effective, is to reduce the size of allowable escape cord (“rot cord”) that opens an escape hatch for the crabs to get out. Studies have shown that approved escape cord takes between 30 and 148 days to disintegrate, and most people use larger cord to last longer.

The time that crabs are trapped and dying on the bottom could be reduced if the rules were changed to require smaller cord. Any rule changes would include a grace period, Childers said, and it would be nice if crabbers could obtain the smaller cord for free.

With crab season underway, a series of videos on the theme “Catch more crab!” couldn’t come at a better time:

A longer video shows how to modify a crab pot to make sure that crabs can escape when a crab pot is lost:

“Modify your crab pot: adding bungee cord & modifying escape ring”

The video below provides basic information for first-time crabbers. Meanwhile, outdoors writer Mark Yuasa offered a nice instructional story last week in the Seattle Times.

To check on crab seasons and legal requirements, visits the Recreational Crab Fishing webpage of the Washington Department of Fish and Wildlife.

Olympia oysters fare better than Pacifics in acidified oceans

Our native Olympia oyster may seem small and meek, but its slow-growing nature may serve it well under future conditions of ocean acidification, according to a new study.

Olympia oysters // Photo: Wikimedia commons
Olympia oysters // Photo: Wikimedia commons

In fact, the tiny Olympia oysters appear to reproduce successfully in waters that can kill the offspring of Pacific oysters — a species that grows much larger and provides the bulk of the commercial oyster trade in Washington state.

Unlike Pacific oysters, Olympias don’t begin forming their shells until two or three days after fertilization, and the formation progresses slowly, helping to counteract the effects of corrosive water, according to the author of the new study, George Waldbusser of Oregon State University.

Betsy Peabody of Puget Sound Restoration Fund said people who work with Olympia oysters have long suspected that they may have some advantages over Pacific oysters. Olympia oysters keep their fertilized eggs in a brood chamber inside the shell until the larvae are released into the water about two weeks later.

In contrast, the eggs of Pacific oysters are fertilized in the open water and the resulting larvae must fend for themselves right away.

While the brood chamber may protect the larvae from predators, the new study showed that the brood chamber does not protect against ocean acidification. Corrosive water still circulates through the mother’s shell, exposing the larvae.

To test how Olympia oysters would do in open waters, the researchers grew baby oysters outside the brood chamber where they were exposed to acidified water, noted Matthew Gray, a former doctoral student in OSU’s Department of Fisheries and Wildlife. He is now conducting research at the University of Maine.

“Brooding was thought to provide several advantages to developing young, but we found it does not provide any physiological advantage to the larvae,” Gray said in an OSU news release. “They did just as well outside the brood chamber as inside.”

It appears that a major difference in the development of Pacific and Olympia oysters lies in their reproductive strategies, including differences in managing their energetics.

“Pacific oysters churn out tens of millions of eggs, and those eggs are much smaller than those of native oysters, even though they eventually become much larger as adults,” Waldbusser said. “Pacific oysters have less energy invested in each offspring. Olympia oysters have more of an initial energy investment from Mom and can spend more time developing their shells and dealing with acidified water.”

The research team found that energy stores in young Pacific oysters declined by 38.6 percent per hour, compared to 0.9 percent in Olympia oysters. Pacific oysters put their energy into building their shells seven times faster than Olympia oysters. The exposure to acidified water affects shell development. While the larval oysters may get through the shell-building stage, they often don’t have enough energy left to survive, Waldbusser said.

The study, funded by the National Science Foundation, was published in the Journal of Limnology and Oceanography.

Puget Sound Restoration Fund has been working for nearly 20 years to restore Olympia oysters at 19 priority locations throughout Puget Sound. The new study lends credence to the effort and support for a recommendation by the 2012 Blue Ribbon Panel on Ocean Acidification. The panel called for restoring the native oyster to Puget Sound to build resilience into the ecosystem, according to Betsy Peabody.

“It was a recommendation that came out before we had the critical science to support it,” Betsy told me. “He (Waldbusser) has just given us the underlying research that supports that recommendation. Our grandchildren may be cultivating Olympia oysters rather than Pacific oysters.”

The panel, appointed by former Gov. Chris Gregoire, called for maintaining the genetic diversity of native shellfish to provide the species a fighting chance against ecological changes brought on by climate change.

Benefits of the Olympia oyster, including so-called ecosystem services, are described in an article by Eric Wagner in the Encyclopedia of Puget Sound. Healthy oyster reefs offer benefits such as cleaning up the water, protecting shorelines from erosion and increasing habitat complexity, which can expand the diversity of sea life.

So far, Puget Sound Restoration Fund has restored 50 acres of shellfish to Puget Sound, working toward a goal of restoring 100 acres by 2020.

Oyster hatcheries in Washington state underwent a temporary crisis a few years ago when Pacific oyster larvae were dying from acidified seawater pumped into the hatcheries. The water still becomes hazardous at times, but careful monitoring of pH levels has allowed hatchery operators to overcome the problem. When the water in an oyster hatchery moves beyond an acceptable pH level, operators add calcium carbonate to alter the pH and support the oyster larvae with shell-building material.

Bill Dewey of Taylor Shellfish Farms said older oysters might be affected in the future as ocean acidification progresses. “We know things are going to get worse,” he told me.

Because of their small size and high cost of production, Olympia oysters will never overtake the Pacific oyster in terms of market share, Bill said, but they are in high demand among people who appreciate the history of our only native oyster and its unique taste.

The new research by Waldbusser raises the question of whether the highly commercial Pacific oysters could be bred so that their larvae grow slower and perhaps overcome the effects of ocean acidification.

Joth Davis, senior scientist for Puget Sound Restoration Fund and senior researcher for Taylor Shellfish, said the market is strong for a smaller Pacific oyster, so most growers would not object to one that grows more slowly with greater survival.

Meanwhile, efforts are underway to maintain the genetic diversity of Olympia oysters and other native species, as growers begin to think about cultivating more natives. Transplanting species from one area to another and boosting their populations with hatcheries creates a potential to override local populations and weaken overall genetic diversity, Joth said.

Geoduck clams, which can be started in hatcheries and grown on a large scale, don’t appear to be genetically distinct from one place to another in Puget Sound, Joth said.

Researchers have found some evidence that Olympia oysters may be genetically distinct when comparing one area of Puget Sound to another. But finding genetic differences does not always mean the population is uniquely adapted to that area, Joth said. Variations might relate to a random population that settles in a specific location. Sometimes it takes careful study to make sense of the differences.

Rich Childers, Puget Sound shellfish manager for the Washington Department of Fish and Wildlife, said the state currently has no firm rules for transferring native species from one place to another. With growing interest in cultivating Olympia oysters, sea cucumbers and other native species, the agency is opening discussions about what kind of controls might be needed.

“We’ve learned lessons from salmon that you can’t spread everything from hell and gone,” Rich said. “Should we be looking at some management or hatchery guidelines that would help maintain genetic diversity? Should we have laws or policies? These are the questions that are just starting to surface.”

Automated monitor provides early warning of harmful algae blooms

Automated equipment installed Monday off the Washington Coast will track concentrations of six species of plankton that could become harmful to humans and marine species.

The Environmental Sample Processor, or ESP, collects discrete samples of water and processes them for analysis. Imbedded modules can test for DNA and antibodies to identify the organisms picked up in the seawater. Concentrations of the plankton and their toxins are sent to shore-based researchers via satellite.

The equipment was installed by scientists with the National Oceanic and Atmospheric Administration and the University of Washington. The device was developed at the Monterey Bay Aquarium Research Institute. Stephanie Moore of NOAA’s Northwest Fisheries Science Center explains the benefits of the device in the first video on this page. The second video provides a few more technical details with graphic depictions of the device.

The ESP was deployed in the Juan de Fuca eddy, a known pathway for toxic algae 13 miles off the Washington Coast near LaPush. The remote, self-operating laboratory will operate about 50 feet underwater.

One of the primary targets of the monitoring is Pseudo-nitzschia, a harmful algae capable of producing domoic acid. This toxin can accumulate in shellfish and can cause diarrhetic shellfish poisoning, which can progress to severe illness. Last year, a massive bloom of this toxic algae canceled scheduled razor clam seasons on Washington beaches with untold economic consequences.

The harmful algal bloom (HAB) affected the entire West Coast, from California to Alaska. It was the largest and longest-lasting bloom in at least 15 years, according to NOAA’s National Ocean Service.

“Concentrations of domoic acid in seawater, some forage fish and crab samples were among the highest ever reported in this region,” says a factsheet from the service. “By mid-May, domoic acid concentrations in Monterey Bay, California, were 10 to 30 times the level that would be considered high for a normal Pseudo-nitzschia bloom.”

“Other HAB toxins were also detected on the West Coast. Shellfish closures in Puget Sound protected consumers from paralytic shellfish poisoning and diarrhetic shellfish poisoning.”

Paralytic shellfish poisoning is associated with a group of plankton called Alexandrium, typically Alexandrium catenella in the Puget Sound region.

In addition to sampling for Alexandrium and four species of Pseudo-nitzchia, the ESP is monitoring for Heterosigma akashiwo, which is associated with massive fish kills, including farmed salmon.

Anyone can track some of the data generated by the equipment by visiting NANOOS — the Northwest Association of Networked Ocean Observing Systems.

Early warning of toxic algal blooms can assist state and local health officials in their surveillance of toxic shellfish.

“Anyone can access the data in near-real-time,” UW oceanographer and NANOOS Director Jan Newton told Hannah Hickey of UW News and Information. “It’s an early warning sentry.”

Elwha River:
a continuing march
on the way to renewal

It has always been a question to ponder: Will the most significant changes to the Elwha River ecosystem occur upstream of where two dams have been removed or downstream where the river enters the Strait of Juan de Fuca?

Photo: Olympic National Park
Photo: Olympic National Park

Soon after each dam was torn down in succession — the lower one first — salmon began migrating upstream, while more than 30 million cubic yards of sediment began moving downstream.

It could take a number of years to rebuild the extensive runs of salmon, including the prized chinook for which the Elwha was famous among salmon fishermen across the country. Will we ever see the legendary 100-pound chinook return to the Elwha, assuming they ever existed? That was a question I explored in a story for the Kitsap Sun in September 2010.

On the other hand, massive amounts of sediment have already spilled out of the Elwha River, building an extensive delta of sand and gravel, including about 80 acres of new habitat and two miles of sandy beach.

Reporter Tristan Baurick focused on the dramatic shoreline changes already taking place at the mouth of the Elwha in a well-written story published in Sunday’s Kitsap Sun.

The Coastal Watershed Institute, which is monitoring the shoreline near the mouth of the Elwha has documented increases in critical forage fish populations, including surf smelt, sand lance, eulachon (candlefish) and longfin smelt. See CWI Blog. These fish feed a host of larger fish, birds and marine mammals.

Tristan describes the changes offshore, where an area starved of sediment is turning into prime habitat for starry flounder, Dungeness crab and many other animals. Rocky outcroppings that once provided attachment for bull kelp is giving way to fine sand, which allows for colonization by eelgrass and a host of connected species. I described some of the early changes in the flora in a Kitsap Sun story in March of 2013.

For people to view the restoration first-hand, I described a day trip to the Elwha in a Kitsap Sun story in April of 2013. Along the way, you can check out the history, enjoy the vantage points and learn about the changes taking place. Tristan offers a suggestion worth heeding to ensure ongoing beach access.

“Access to the beach is granted by the dike’s owners. They could take that away if the area’s overwhelmed with trash, noise and other nuisances, so keep that in mind when you visit.”

If you’d like to see a video record of dam removal and ecosystem recovery, you may wish to view the film “Return of the River” to be shown at Bremerton’s Admiral Theatre on Friday, March 13. The film will be followed by a panel discussion involving the film’s producers, John Gussman and Jessica Plumb. For details, check the Kitsap Sun website.

How to help crabs survive when you
lose a crab pot

A simple alteration to recreational crab pots could save thousands of crabs from going to waste each year, all because crabs are unable to escape from lost crab pots that keep on working, according to a new study.

Paul Rudell of Natural Resources Consultants, left, and Jason Morgan of Northwest Straits Foundation place crabs into a trap to test the escape system. Photo: Northwest Straits Foundation
Paul Rudell of Natural Resources Consultants, left, and Jason Morgan of Northwest Straits Foundation place crabs into a trap to test the escape system.
Photo: Northwest Straits Foundation

The Crab Pot Escapement Study, commissioned by the Northwest Straits Foundation, is the first to measure how well crabs use the escape routes provided in the design of every crab pot sold in Washington state.

The findings were somewhat of a surprise, according to Jason Morgan of the Northwest Straits Foundation. Jason told me that he is eager to get the information out to recreational crabbers, who could voluntarily take steps to reduce crab mortality. The findings might even lead to revised regulations for crab pots.

Of course, the best thing that crabbers can do is to avoid losing their pots in the first place. For tips, check out the brochure from the Washington Department of Fish and Wildlife (PDF 2.9 mb) or the Northwest Straits website. About 12,000 crab pots are lost each year in Puget Sound, representing the wasteful deaths of nearly 200,000 crabs, according to a revised estimate derived from the new study.

The study, in partnership with Natural Resources Consultants, placed live Dungeness crabs into six common types of crab pots, using 13 various configurations. After the seventh day, the biodegradable escape cord (“rot cord”) was severed to provide an opening through which the crabs could escape — at least in theory. The researchers then measured the time it took for the crabs to get out, if they could.

An escape ring tied with escape cord allows crabs a way out. Photo: Northwest Straits Foundation
An escape ring tied with escape cord allows crabs a safe exit.
Photo: Northwest Straits Foundation

One thing the researchers learned was that crab pots with hinged doors tended to keep the crabs trapped, especially when the door was located away from the edge of the pot. The doors simply stayed closed after the escape cord broke free.

A modification of the doors with a bungee cord significantly increased the number of crabs that could escape. The doors were modified to spring open when the escape cord broke.

The best configuration of all involved the use of escape rings — a circular opening at least 4.25 inches across. These rings are required by law in all crab pots to allow females and under-sized males to get away before the pot is brought to the surface or in the event that it becomes derelict.

Many crab pots sold today tie the rings into the crab pot with escape cord. When the cord breaks, the ring falls away to provide a larger opening for the crabs to get out.

“It’s still a small opening for the crab to crawl out,” Jason said. “We did not expect it to be effective at all, but it works very well.”

In some crab pots, the required rings are welded into place on the iron cage. It would be easy enough for people to cut the rings out with a strong pair of wire cutters and then tie them back in with escape cord, Jason said.

Manufacturers of crab pots have become interested in the study, Jason told me, and he expects some will quickly convert to tying the rings in place rather than welding them. The difference in cost, if any, should be small, he said, and drawbacks seem minimal.

Requiring this method of escape for future crab pots sold in Washington could be another result of the study, but nothing is proposed at this time, Jason said. The next round of studies is likely to look at commercial crab pots, which are generally larger but still require an escape route in case they become lost.

A related issue that needs attention is the escape cord, which is made of cotton and designed to deteriorate in a reasonable period of time when left in saltwater. Cords that last longer are likely to cause more crabs to die. Studies have shown that approved escape cord takes between 30 and 148 days to disintegrate, with most people selecting larger cord that can last toward the longer end of that range.

“That is certainly something that we are not happy with,” Jason said. “We would like to see regulations that would require escape cord to be smaller.”

A smaller cord would break sooner and allow more crabs to survive when a crab pot is lost, though it would require crabbers to change the cord more often. That would seem to be a small inconvenience to avoid the kind of waste often seen in photos of derelict crab pots filled with dead and dying crabs. Even longtime experienced crabbers can lose a pot now and then, Jason said.

Northwest Straits Foundation is working on one or more videos to help people see the benefits of providing escape for crabs and to demonstrate how to modify their crab pots.

According to the study, the right modifications to crab pots could allow 99 percent of the crabs to get free when a crab pot is lost in the depths of Puget Sound.