SEQUIM — Higher temperatures brought about by global climate change most likely will damage critical habitat for young salmon in western Washington waterways — and development in places like Puget Sound and the Strait of Juan de Fuca could hamstring nature’s ability to adapt.
That’s the finding of research conducted at the Marine Sciences Lab in Sequim, part of the Pacific Northwest National Laboratory.
Ronald Thom, a scientist working on the lab’s Coastal Assessment and Restoration team, presented the findings last week at the Puget Sound/Georgia Basin Conference in Seattle.
Research so far indicates that global warming will cause water temperatures and sea levels to rise, Thom said.
The deeper, warmer water will cover eelgrass beds, reducing the amount of light received, making it harder for the grass to survive and possibly eliminating part of the environment used by many marine creatures.
“Young salmon, particularly chinook, utilize eelgrass meadows for feeding and refuge on their outmigration” from rivers, Thom said.
These meadows also may harbor as many as 50 or 60 species of fish and invertebrates, and organic matter from the eelgrass is part of the marine “food web,” he said.
Manmade impediments
In many cases, eelgrass won’t be able to migrate upshore with the rising waterline, Thom continued, because of development such as seawalls and bulkheads. Construction along the shore tends to eliminate the conditions eelgrass need to thrive, he said.
“The armoring of the shoreline tends to result in the loss of fine sediments, so it restricts where eelgrass can grow,” he said.
Research so far has examined conditions in Puget Sound, area straits and Willapa Bay.
Thom said conditions along the Strait of Juan de Fuca along the North Olympic Peninsula are “far better than many places in Puget Sound” because of less development.
Even an undisturbed coastline may present challenges, though.
Many natural beaches, for example, are surrounded by high, steep rocks that wouldn’t be very welcoming to eelgrass as water levels rise.
Early stages
Thom stressed that the research is in its very early stages.
“It needs a lot of verification,” he said.
“The next thing is to really sort out the mechanism and really verify it through monitoring. We’re hoping that we can get more funding to work on it.”
That may be easier said than done, however.
Thom said most research funds are dedicated to either deepwater projects or land-based ones, with shoreline studies often taking a back seat.
“There’s a very weak, almost noneffective, program for shallow water [research],” he said.
“It’s a tough nut to crack as far as funding to do the work.”
The Pacific Northwest National Laboratory is one of nine labs doing work for the U.S. Department of Energy. Battelle, a nonprofit corporation based in Columbus, Ohio, manages the lab.