Category Archives: Invasive species

You can join the search for beetles that threaten Washington trees

Washington state property owners and people with swimming pools are being urged to become part of a defensive initiative to protect trees from invasive beetles.

August is National Tree Check Month, and at least four state agencies are asking tree owners this month to take a 10-minute walk around their property to look for insects that don’t belong in our region.

Nationwide, more than a third of all insect invasions are first detected by average people, according to Justin Bush, executive coordinator of the Washington Invasive Species Council. Heading off an invasion before it gets started could save untold millions of dollars worth of trees, as well as the costs of battling a spreading insect invasion.

Citrus longhorned beetle
Photo: USDA Plant Protection Service, Bugwood.org

This is the second year that Washington state agencies are bringing the message home from other states where many longtime tree populations have been decimated by insects, including the citrus longhorned beetle and the emerald ash borer.

“While we don’t have these two invasive insects right now, we could get them at any moment,” Justin told me. “We want people to help us look for them.”

This year, state officials also are asking people who own swimming pools and ponds to join in the defensive effort, as some of invasive insects end up in the water and die. A swimming pool owner or maintenance person should take note of any unusual insects found in pool filters or among debris skimmed off the surface of the water, he said. On the East Coast, swimming pool owners are often able to spot invasive beetles even before they show up in traps designed to attract them.

It would be helpful if people would look for invasive insects all year long, Justin said, but August is a good time to place a special emphasis on the effort, because this is the time that most wood-boring insects emerge as adults.

Emerald ash borer
Photo: Debbie Miller, U.S. Forest Service, Bugwood.org

Identifying specific species of beetles is often difficult, Justin acknowledged. The best advice is to take pictures of the insect from several angles and send the photos to the Invasive Species Council, InvasiveSpecies@rco.wa.gov, which will find an expert to identify the bug.

People shouldn’t hesitate to send photos, Justin said. “If it comes to us, we can figure it out.”

Another reporting method is to download the “WA Invasives” app to send photos and location data straight from your smart phone. See WISC download page. The app also includes photos and information for identifying invasive species.

When emailing, one should include contact information, including a phone number, along with the location of the insect sighting. (An address or cross-street description would be helpful.) Details about the tree species should be included as well.

If you obtain one of the beetles, you should keep it in case an expert wants to inspect the specimen. Another option is to take the beetle to a local office of WSU Extension, which can forward it to appropriate experts.

The citrus longhorned beetle, a close relative of the disastrous Asian longhorned beetle, is a major concern on the West Coast. The beetle can feed on a variety of hardwood trees, including apple, maple, oak, willow, alder and popular. When they emerge, they leave an exit hole about 5/8-inch in diameter in the tree.

In 2001, the citrus longhorned beetle was found in Tukwila, where it arrived in a shipment of bonsai trees. Three beetles were recovered from the bonsai trees but five others were seen flying away. Nearly 1,000 trees were cut and chipped within one-eighth mile from the location site, and another 1,500 trees farther away were treated with insecticide. The last beetle was seen in the fall of 2002, and a quarantine remained in effect until 2006. See U.S. Department of Agriculture website.

Because of heavy shipping from Asian ports, concerns remain high that damaging beetles will be imported to the West Coast, Justin said. Insects could also arrive from infested areas back East, which is the primary route for European gypsy moths brought into Washington state in moving vans. This state’s gypsy moth eradication program — including nearly 100 local battles since 1979 (PDF 307 kb) — has kept the damaging moths from establishing a permanent foothold in this state.

Besides the citrus longhorned beetle, officials are concerned that the emerald ash borer could devastate ash trees in this state. The exit holes in ash trees are about a quarter-inch in diameter and have a distinctive “D” shape. Ash trees are common in urban areas, and the beetles apparently have been moving westward as campers bring firewood from eastern areas. The beetle was recently discovered in Boulder, Colo.

State agencies involved in the effort to track down the invasive beetles are the Invasive Species Council, Department of Agriculture, Department of Natural Resources and Washington State University Extension.

The U.S. Department of Agriculture offers information on these and other invasive insects:

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: Underwater mysteries of the national parks

Mysterious underwater areas can be found in numerous national parks and national monuments throughout the United States. The National Park Service operates a special division, the Submerged Resources Center, to explore some of the mysteries.

To share its underwater exploration and preservation efforts, the Park Service has created seven films in partnership with CuriosityStream, a documentary production and distribution company. Though longer than most videos featured in “Amusing Monday,” I believe the science and history revealed in these fascinating films are well worth the time.

The Submerged Resources Center, which has been in existence more than 30 years, has been recognized as a leader in documenting, interpreting and preserving underwater resources. As you will see in the films, the research teams use some of the most advanced underwater technologies. Their mission is to support the National Park Service’s preservation mandate and to enhance public appreciation, access and protection of these resources. Areas of focus include archeology, marine survey, underwater imaging and diving.

I have embedded three videos on this page, but I’m providing the full list here, with links, also accessible on the National Park Service’s website called “Underwater Wonders of the National Parks.”

Devil’s Hole: This unique underwater cave can be found in Death Valley National Park on the border between California and Nevada northwest of Las Vegas. The film features a unique species of fish called the pupfish, which are among the most endangered species in the world. Assessing and protecting these fish is a major responsibility of the Park Service. Another good story with photos and video was featured in The Desert Sun newspaper of Palm Springs, Calif.

Montezuma Well: Swirling sands at the bottom of this lake create spooky conditions for divers who cannot find the bottom and often find themselves sucked into a kind of quicksand. The “well” can be found within Montezuma Castle National Monument south of Flagstaff, Ariz. Few creatures can survive in the waters rich in carbon dioxide and arsenic and fed by pressurized water vents. But divers are monitoring the populations and interactions among four species found there: diatoms, amphipods, snails, non-blood-sucking leaches and water scorpions.

USS Arizona, Part 1: The USS Arizona, which sank during the attack on Pearl Harbor, is a national memorial to the 1,177 sailors who went down with the ship. The National Park Service is responsible for monitoring conditions — including sea life — in and around the Arizona.

USS Arizona, Part 2: The second video on the Arizona Memorial features more about the history of the ship and artifacts still being discovered. Divers are serious about their solemn roles. For example, World War II survivors of the attack may choose to be reunited with their shipmates, so urns with their remains are moved into a special place aboard the sunken battleship.

Yellowstone Lake: Thermal vents and impressive geothermal spires are unique to the freshwater habitat of Yellowstone Lake, which lies in the center of Yellowstone National Park in Wyoming. A major concern is the survival of the lake’s native cutthroat trout, which are being consumed by the voracious lake trout, an invasive species. Mapping the lake’s bottom to locate the lake trout’s spawning grounds is one idea to help contain the problem.

Lake Mead: The first national recreation area in the United States, Lake Mead, which is east of Las Vegas, was formed by the construction of Hoover Dam in an area known for its military secrets, including Area 51. In 1948, a B-29 bomber crashed and sank in the lake while conducting research into a new navigational concept, which eventually became incorporated into guidance missile systems. The aluminum aircraft is well preserved on the bottom of the lake, although it is now encrusted with invasive quagga mussels, which spread too fast for divers to keep track of them.

Buck Island: An amazingly productive ecosystem can be found within Buck Island Reef National Monument in the U.S. Virgin Islands of the Caribbean. Experts monitoring the reef’s conditions must experience mixed emotions, as they document the amazing sea life as well as “bleaching” of the coral reef, portions of which are dying from disease. Divers have been able to save some of the corals by chiseling away the infected areas. The National Park Service also documents the history of the slave trade as it explores for artifacts from more than 100 slave ships that sank in the Virgin Islands — including at least two near Buck Island.

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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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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Ballast water bill could allow invasive species to enter Puget Sound

Invasive species from San Francisco Bay — known as the most infested waterway in the country — would have an open door for entry into Puget Sound under a bill moving through Congress.

Vessel Incidental Discharge Act invasive species
Ballast discharge from a ship
Photo: Coast Guard

You may have heard this line before. I posted the same warning last summer, when the Vessel Incidental Discharge Act, or VIDA, was attached to the “must-pass” National Defense Authorization Act. (Water Ways, July 16). Opponents fought back and were able to strip VIDA from the bill before final passage.

Now, with Republicans in control of both houses of Congress and an anti-regulatory atmosphere in place, the bill’s passage seems more likely this time — to the detriment of Puget Sound, the Great Lakes and other waterways.

If VIDA passes, ships coming up the coast from California will be able to take on infested ballast water in San Francisco Bay and discharge it without treatment into Puget Sound. Invasive species that hitched a ride in the ballast water would have a chance to populate Puget Sound.

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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.

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