SEVERE CARAPACE DISSOLUTION sounds like some sort of underhanded legal maneuver, not a by-product of increasing Pacific Ocean acidification on Dungeness crab shells.
But we’ve reached the point in which increasing levels of carbon dioxide in our atmosphere are more and more absorbed by the Pacific Ocean, so much so that the shells of some Dungeness crab larvae are becoming pitted and folded — dissolving even as they attempt to grow to adulthood, according to new scientific research.
And these conclusions come much, much sooner than researchers had anticipated.
The study was published last week in the Science of the Total Environment academic journal and funded by the federal National Oceanic and Atmospheric Administration (NOAA). It is based on a 2016 survey of Oregon, Washington and British Columbia coastal waters that looked at larval Dungeness.
Its findings point to increasing acidity affecting the shells of crab larvae, making them more vulnerable to predators while also limiting the ability for crab shells to support the growth of muscles.
Lower pH levels have also helped destabilize the larvae’s mechanoreceptors, raising the potential for the loss of important sensory and behavioral functions.
“If the crabs are affected already, we really need to make sure we start to pay attention to various components of the food chain before it is too late,” said Nina Bednarsek, the lead author among 13 contributing scientists.
The study did not come to a conclusion on the effect of acidity on adult Dungeness crabs.
But the researchers hypothesized that “aberrant behavioral patterns found across various crustacean species … such as slower movement, less tactile, prolonged searching time, as well as impaired swimming” could be due to increased acidity.
Dungeness crab sustain West Coast commercial seafood harvests typically worth more than $200 million annually, and are a mainstay for tribal and recreational crabbers.
It would follow that Puget Sound, and the Strait of Juan de Fuca also are impacted by the same increasing acidification.
Hood Canal shellfish also are being impacted by acidification where pH levels as low as 7.4 have been recorded.
Hoko retention reopened
It may be too little too late for anglers to enjoy the hatchery steelhead run on the Hoko River, but the water body has re-opened to fishing from the mouth to the Ellis Creek Bridge at river mile 18.5.
The re-opening comes after hatchery broodstock needs have been met at the Hoko Falls Hatchery.
The Hoko River is a West End river that does round back into form faster than others after rainfalls, so bear that in mind if cabin fever has you in need of some time outside.
Fly fishers meet Monday
Greg Shimek, executive director of the Coastal Cutthroat Coalition, is the speaker at Monday’s meeting of the Olympic Peninsula Fly Fishers club at 6 p.m.
Shimek will discuss secrets of the coastal cutthroat trout, also known as sea-run cutthroat trout or harvest trout, discovered in recent studies.
There also will be a fly-tying demonstration and discussion of an upcoming club outing at Pooh’s Pond in the Eden Valley area March 28.
The fly fishers’ meetings, open to all interested anglers, are held in the Campfire USA Clubhouse in Jessie Webster Park, 614 E. Fourth St., in Port Angeles the first Monday of every month.
For more information, contact Charles Whitney at 360-457-2799 or crwinc@olypen.com.
Avalanche safety
Hurricane Ridge and the Olympic mountain range has an abundance of backcountry to explore, but getting caught in an avalanche is always a concern.
Learn how to be safe while enjoying beautiful scenery with Northwest Avalanche Center Instructor Sam Luthy during a presentation on avalanche safety on Feb. 8.
The presentation will be held in the Landing Mall, 115 E. Railroad Ave., on the second floor across the hall from Smuggler’s Landing.
The talk is focused on the unaware backcountry traveler and Luthy’s presentation will introduce the concepts of avalanche danger recognition and how to reduce risk, along with where and why avalanches occur, understanding who gets caught in avalanches and why and providing a basic approach to staying safe in the backcountry.
This talk is presented by the Northwest Avalanche Center, Hurricane Ridge Winter Sports Club and the Hurricane Ridge Ski Team. The suggested donation is $10.
