Oregon State University (OSU) researchers are concerned about the sudden mussel die-off in recent months. They are unsure why the invertebrate population took a sudden nose dive this summer. Perhaps it is the result of a naturally occurring toxin or climate change.
April Ehrlich, an Oregon Public Broadcasting (OPB) reporter, joined OSU professor and ecologist Bruce Menge and his research team at a tide pool in Depot Bay in mid-August to learn more about the recent decline.
Menge told her, “mussels at research sites across Oregon had been dying at alarming rates since June.”
He continued, “And they’re doing it in sort of a random why. It’s not all mussels in a given area, but it’s one here, one there, one over there.”
“But it adds up to numbers that are way higher than anything we’ve ever seen before.”
The professor also said this uptick has also been reported by British Columbia and Northern California’s researchers.
However, the increase in these sea creatures dying “doesn’t seem to extend further south.”
The OSU researchers removed dead mussels. This is important because they can get an accurate count of new deaths when they return in a few weeks.
After collecting the dead invertebrates and some apparently healthy ones, the team’s buckets would be sent to labs where the seawater and mussel tissue would be tested for toxins, physical deformities, and more.
Did Warmer Water Cause this Summer’s Mussel Die-off?
Professor Mange said does not blame warmer waters for this mussel die-off because Oregon’s coastal waters have been relatively cool this year. He thinks the invertebrates’ deaths might be tied to several upwellings that hit the state’s coast this summer.
According to the National Oceanic and Atmospheric Administration (NOAA), “upwelling is a process in which deep, cold water rises toward the surface.”
The “displaced surface waters are replaced by cold, nutrient-rich water that well up from below.”
These nutrients fertilize surface waters, encouraging the growth of plant life, including phytoplankton.”
Menge thinks the phytoplankton might have released toxins into the water, negatively affecting mussels’ digestion systems. “If that hypothesis is correct, it might be that they’re simply starving, even though there’s a lot of food in the water.
The rise in seawater surface temperature affects invertebrates and other marine organisms. Hotter water and other climate change-related anomalies have chronically stressed the mussels.
Professor Menge told OPB that he has seen reproduction rates declining in the 25 years he has studied these sea creatures. He also spoke of their shells shrinking and decreased tissue.
Mussels Are Vital to the Environment
Mussels “are sort of on the edge, and it’s a little — it’s a lot concerning,” Menge added. “If we lost all of these mussels, it would be an environmental catastrophe.”
These invertebrates and coral are foundation species. This class of species has a disproportionately large effect on its natural environment relative to its abundance.
In other words, hundreds of other species rely on them for food or shelter. The massive clusters of mussels provide a perfect space for seaweeds to make a home.
Starfish rely on them for food, and barnacles cling to their shells. Birds eat the invertebrates.
Written by Cathy Milne-Ware
OPB: Oregon mussels died at alarming rates this summer. Researchers don’t know why. By April Ehrlich
NOAA: What is upwelling?
National Library of Medicine: Chronic environmental stress enhances tolerance to seasonal gradual warming in marine mussels; by Ionan Marigómez, Maria Múgica, Urtzi Izagirre, and Inna M. Sokolova
Featured and Top Image by EJ Strat Courtesy of Unsplash
First Inset Image by derRenner Courtesy of Pixabay – Creative Commons License
Second Inset Image by Travis Courtesy of Flickr – Creative Commons License
Third Inset Image by Andy Castille Courtesy of Unsplash