As you are probably aware, the oceans absorb a lot of atmospheric carbon dioxide, and the rate of that absorption has increased with greater fossil fuel based human activities. For a decade or more now, marine scientists have been tracking the downward trend in the pH of the ocean, the process now known as ‘ocean acidification’. The effect is more pronounced at the poles and has been extending slowly southward into the waters of Washington and Oregon in our home region.
Oyster culture in the Pacific Northwest relies heavily on a few hatchery sources for annual production of larvae (spawn). In 2007 the primary hatchery on the coast of Oregon had a complete failure of spawning. This failure was determined to be due to the lower pH of the seawater being pumped into the hatchery which inhibits the formation of shells in the larvae.
In the 1990’s both Jessica and I worked in the Willapa Bay region of southwest Washington, a famous oyster culture area. One of the growers there, Goose Point Oysters, has opened an oyster hatchery here on the Big Island, just south of Hilo. In fact Dave Nisbet, the owner, is a board member of the Coastal Oregon Marine Experiment Station which is where Jessica works at OSU. Dave Nisbet describes the decision to move the hatchery to Hawai`i “a matter of survival”. So far the ocean in Hawai`i is not showing any decreases in pH.
A few weeks ago, we were able to visit with Dave at the hatchery during one of his extended visits from Washington. The hatchery is not right on the ocean, but a half-mile inland, and pumps seawater into the hatchery from a 350′ ft. well!
Oysters are spawned in these large tanks.
Oyster larvae are grown out to a certain size fed on cultured phytoplankton
Phytoplankton food grown out in big plastic bags!
Oyster larvae are collected by draining the tanks through these filters, and millions of larvae are shipped to Washington by Fedex in a package the size of a softball!
The algae lab researches new mixes of phytoplankton food.
(left to right) – James Akau, Jessica, and Dave Nisbet (James is Jessica’s field and lab tech on her gobie project).
You can read online media stories about ocean acidification and oyster culture problems here:
Research and evidence that OA impacts oyster culture since 2007
Opening of new hatchery in Hawai`i