Yellow Pages
BAY VIEW — In 100 years, climate change will cause the level of Padilla Bay to rise between 1.8 and 6 feet, and its impact on the ecology of the area is still largely unknown, according to a Western Washington University researcher.
John Rybczyk, a professor of environmental science at Western’s Huxley College of the Environment who specializes in wetlands, is working to shed some light on one of those unknowns.
Rybczyk and his graduate students have been studying the bay’s eelgrass, a marine vegetation that grows in shallower water and can be partially exposed at low tide.
Eelgrass provides food and shelter for dozens of species from tiny plankton to migrating geese. Scientists consider the marine grass important to herring on which salmon depend for food.
Determining what could happen to eelgrass when the oceans rise is important to understanding the impact of climate change on other marine species, such as commercial fishing stocks including crabs, salmon and herring.
On Wednesday, Rybczyk presented some of his initial findings to an audience of about 25 scientists and others at the Padilla Bay National Estuarine Research Reserve.
Rybczyk, his graduate students and two other researchers are building a complex computer model to predict the impact of sea-level rise on tribal salmon habitat restoration projects in the Skagit River estuary.
Rybczyk and his then-graduate student Pete Kairis incorporated data from field work into a computer modeling program to predict the impact of sea-level rise on eelgrass.
Padilla Bay, which was part of the Skagit River Delta more than a century ago, isn’t unique. Rising seas are causing problems for coastal systems worldwide. That’s in part because dams and levies in many delta systems prevent the rivers from depositing sediment, which would raise the height of bays such as Padilla.
Assuming depth of water is the only variable, Rybczyk said that his research shows that the location of the roughly 7,410 acres of eelgrass in the bay will shift over the next 100 years. Eelgrass will eventually grow closer to the shoreline where the mudflats are now exposed at low tide, he said.
But this doesn’t mean that the eelgrass will thrive. It just means there will be a place for it to grow.
“I don’t want anyone to go away and think there’s no problem with sea-level rise,” Rybczyk said.
Rybczyk and Richard Gwozdz, another graduate student, tried unsuccessfully to build a computer model that would take temperature changes into account.
As a result, Rybczyk said there are questions that other researchers need to answer.
For instance, he said, if eelgrass beds are 3 feet deeper under water than they are today, can Brant geese dive deep enough to eat the vegetation? Brant are game birds that winter at Padilla Bay as part of an annual migration from Canada and Russia.
Rybczyk said that Greg Hood, a senior restoration ecologist at the Skagit River System Cooperative, has spent the past two summers gathering measurements of soil, elevation and salinity.
The data will be used in a more complex computer model that Hood, Rybczyk and other researchers will use to determine the impact of sea-level rise on salmon habitat restoration projects.
“If you want to ask how the habitat will change over time, you have to have that kind of data,” Rybczyk said.
Marta Murvosh can be reached at 360-416-2149 or .
Read more local news in the Skagit Valley Herald and the Anacortes American, or read it online in the E-edition
