Researches Awarded Grant to Study Oregon Coast Ecosystem Changes
The Oregon Department of Fish and Wildlife Marine Resources Program (ODFW) was recently awarded a $250,000 grant to study significant ecosystem changes on the Oregon Coast. Ever since a marine heatwave first occurred in 2013 and lasted until 2015, purple sea urchin populations have been rising rapidly — a 10,000% increase in recent years — while populations of bull kelp, sunflower sea stars and other important marine species like abalone have been depleting.
Steve Rumrill, the Shellfish Program Leader at ODFW, says very little is still known about what’s been causing these population changes.
“One of the thoughts is that the grazing by the purple sea urchins has not allowed the kelp to come back, even when temperatures are okay,” said Rumrill. “It makes sense to think that there’s trophic or food web relationships directly controlling all of this, but we don’t have field experiments or laboratory experiments to directly show the cause-effect relationship.”
Currently, the ODFW is running some field tests by working with volunteer divers, who have thus far removed over 40,000 purple sea urchins from a cove in Port Orford. Tom Calvanese, the OSU field station manager of Port Orford, told OPB this summer that urchin divers in the area had started to develop a food market for the invasive species in response to the danger they presented to the ocean’s kelp forests, which serve as a critical habitat and food source for many organisms in the marine environment.
The grant money will fund more scuba divers and remotely operated vehicles to survey the coast’s ecological changes, and will also fund equipment to monitor ocean temperatures and oxygen levels.
Rumrill said researchers are also considering other experiments to study the decline of these important coastal habitats. Some of these include artificially enhancing kelp spores, or even placing and reintroducing two of the purple sea urchins’ natural predators — sunflower sea stars and sea otters, respectively — to help control the urchins’ population growth.