Mussels form attachments to rocks, fellow mussels and other surfaces with what's called the byssus, a mass of golden-colored threads or filaments. Although each strand is only three to 10 times the width of a human hair, the threads are extraordinarily strong and stretchy, she says.
That's good, given the forces at work where mussels live in the intertidal zone, the part of the shore covered by water when the tide is in and high and dry when it's out.
Carrington says a modest wave on the outer coast of Washington clips along at 10 meters per second.
"An inland stream with water moving at only one meter per second is very hard to stand in," she said. "Imagine something going 10 times that speed over your whole body."
Carrington calculates that wind would have to blow 600 miles per hour to generate the same force as water traveling 10 meters per second.
Carrington's work, based at the UW's Friday Harbor Laboratories and funded by the National Science Foundation, involves field observations of natural populations that she and her team try to repeat in the laboratory. In the lab they change one factor at a time considering such stressors as temperature and ocean acidification to understand which of many possible environmental culprits are most important, she said.
For example in lab experiments led by UW doctoral student Laura Newcomb, the strength of byssal threads formed in water at 77 degrees F (25 C) were 60 percent weaker compared to those formed at 50 F and 65 F (10 C and 18 C). The waters in the natural habitat around Friday Harbor Laboratories is typically 50-54 F (12-14 C) in the summer, she said, although in places like shallow bays it can be much higher.
Scientists have previously found that the byssus weakens naturally in late summer and early fall. When autumn hurricanes and storms hit, both wild and commercia
|Contact: Sandra Hines|
University of Washington