CORVALLIS, Ore. – The rugged ocean waters off Yaquina Head near Newport have made many an Oregonian turn green over the years; now a team of oceanographers is turning the tables.
Oregon State University scientists and students on Thursday. July 14, will drop six samples of bright, fluorescent green dye into the ocean to learn more about near-shore water movement. The dye, known as fluorescein, is harmless to the environment and will degrade after several hours of sunlight, but for a brief time will turn patches of the ocean “a Gatorade green,” said OSU oceanographer Kipp Shearman.
“It is pretty spectacular and should be visible from Yaquina Head,” Shearman said of the dye. “But it’s also a powerful tool for accurately measuring fluid movement, which you can’t do as well with other methods, such as drifters. Fluid can move vertically in the ocean and it can diffuse, and the dye will help us track those movements.”
This pilot project will be directed by students under the supervision of faculty from OSU’s College of Oceanic and Atmospheric Sciences, including Shearman, Jim Lerczak and Jonathan Nash. Leading the project will be Allison Einholf, an undergraduate student from Macalester College who is at OSU this summer as part of the National Science Foundation-funded Research Experience for Undergraduates program, and newly arrived OSU doctoral student Alejandra Sanchez.
Learning more about near-shore water movement is important, Shearman says, because marine organisms living in the intertidal zone or on the beach – including Dungeness crabs, clams and mussels – disperse larva that needs to go out to deeper ocean waters for those species to repopulate. Circulation in this near-shore region is also important in gauging the effects of pollution, contamination from oil spills and the movement of sediment.
Surprisingly, Shearman says, scientists don’t know all that much about water movement just off our own shore.
“It seems so basic and fundamental, but we just don’t know that much about it,” he said. “We know a lot about ocean currents, waves and upwelling, but how water moves from the rocks and surf zone out to the coastal ocean hasn’t been well-documented. One reason is that it’s a tough place to study. OSU’s ships – the Elakha and Wecoma – can’t get in there easily.”
The OSU oceanographers are going out in the private boat of Scott and Selina Heppell, marine ecologists who work in the Department of Fisheries and Wildlife at OSU. Beginning at about 8 a.m. on Thursday, they will drop six floating drifters in the water between the surf zone and a reef about a mile offshore – just south of the Yaquina Head lighthouse – and at each location, will also dispense about a liter of water that has 200 grams of the fluorescein dye.
The dye will disperse and leave trails of bright green water behind – at least, for a few hours – that will be tracked by OSU’s Coastal Imaging Lab cameras located on Yaquina Head. By sunset, the dye should be gone.
Fluorescein is the same dye used by eye doctors to look for physical defects, and by plumbers to test for water leaks.
“If this works well, we may do it again in August or September, and use the results to plan for a more comprehensive study in the future,” Shearman said.