Seward important to ocean acidification research
Walk into the D.W. Hood Laboratory across from the Alutiiq Pride Shellfish Hatchery, and you will come to a room where seawater from Resurrection Bay enters the facility. The water is fed into the hatchery where it is warmed and treated, and where shellfish such as oysters, geoducks, cockles, razor clams, littleneck clams, mussels, scallops and sea cucumbers and even red king crabs are raised.
The seawater pipe now runs through a machine that monitors and records its carbon dioxide, or CO2 concentration. It is dubbed the “Burkolator” for its creator Burke Hales of Oregon State University who Wiley Evans, a research associate worked under prior to his current job with the UAF Ocean Acidification Research Center.
The sampling machine will continue to run at least through next year, said Evans. It will help researchers monitor carbon dioxide concentrations and levels of acidity in Resurrection Bay over time. It may also help the hatchery staff keep high CO2 concentrations from affecting their shellfish, or provide clues as to why certain shellfish die off, or may not survive or grow as expected, said hatchery manager Jeff Hetrick. Some recent die-offs at oyster hatcheries in the Pacific Northwest have been attributed to high CO2 concentrations in the water.
While in Seward Friday, Wiley gave a public seminar on the current scientific understanding of changes in the ocean known as ocean acidification. The seminar, in the K.M. Rae Building auditorium, was attended by about 30 local residents, and their counterparts at UAF in Fairbanks.
In addition to the shellfish hatchery monitor, an ocean-mooring buoy monitor has been placed at the mouth of Resurrection Bay, equipped with sensors that measure the water’s acidity (pH), water temperature, CO2, salinity and other data. Altogether five networked mooring monitors will be placed around the state, with the help of $2.7 million in state funding. The data is streamed to UAF and NOAA-PMEL, the National Oceanic and Atmospheric Administration’s Pacific Marine Environmental Laboratory, or PMEL, which makes ocean observations and equipment.
Evans also met with Tom Tougas of Seward who owns Major Marine Tours and one of his captains who runs the Surprise Glacier Cruise out of Whittier to arrange for water sampling as the ship transits Prince William Sound to Harriman Fjord and Surprise Glacier during next year’s tour season.
Since OARC was established in 2007 by UAF researcher Dr. Jeremy Mathis, researchers have collected data from two cruises a year, in May and September. But field work has ramped up considerably since then to provide more detailed information about how ocean acidification works in certain areas, under certain conditions over time.
The concern is that over the past 200 years humans have been changing the ocean faster than it’s ever changed before, Wiley said. The full effects of ocean acidification are still unknown, but certain marine organisms at the bottom of the food chain are already being affected, and species that humans eat, including shellfish.
Combining recent data with ice core samples stretching back 800 years, scientists have observed a growing trend of atmospheric CO2 concentration in the oceans and graphed its increase. Although CO2 concentrations experienced natural small peaks and dips until 1800, the start of the Industrial Revolution, it has risen steadily since then. If the steep upward spike continues and industrial fossil fuel emissions continue as usual, ocean CO2 concentrations are projected to pass 800 parts per million by 2100, Wiley said. This means our own grandchildren could experience twice the ocean CO2 concentration levels as we currently have, he said.
The waters of the North Pacific Ocean are particularly vulnerable because they already have high CO2 concentrations and low pH, he explained. The colder waters absorb more carbon dioxide, which leads to lower pH and carbonate mineral concentrations, which inhibits shell development. Their research is also showing that the seasonal melting of glacial sea ice adds to the rate of ocean acidification.
Pteropods, tiny marine snails that are a primary food source for salmon, are considered the “ground zero” species, Wiley said. Ocean acidification also affects coccolithophores, the main food source for copepods, another important part of a salmon’s diet, Wiley said.
A colleague of his recently found pteropods’ shells actually dissolving in the Southern Ocean. Until that discovery, the phenomenon had been observed only in a laboratory setting, and at oyster hatcheries in Oregon and Washington, he said. OARC researchers are now looking for evidence of this in the Gulf of Alaska.