Sunday, October 13, 2013

Ocean CO2: Yes It Is Alarming

Barton and others (2012) reported the impacts of ocean pH and available carbonate impacts to Pacific Northwest oysters. The short version of the paper is that lower pH and lower carbonate availability in the water had a detrimental impact of the early life stages of oysters. They note in detail a variety of causes for lowering pH at the particular study site: diurnal effects, local biological activity, organic inputs and most notably upwelling deep cold water with lower pH associated with periodic north wind that pushes surface water (via Coriolis effect) offshore allowing cold deeper waters to upwell along the coast. Barton and others (2012) document how CO2 levels in the ocean water can impact a nearly billion dollar industry in Washington State.

This paper and others has been a cause of alarm for the Washington State oyster industry. Currently oyster growers can do work arounds to get oyster spat to take by limiting spat activities during periods of warmer water when upwelling is not taking place or by buffering the water oyster hatcheries take in. Oysters, particularly the big non native ones grown (natives are grown as well) could be described as living on the fringe in the Pacific Northwest coastal waters in regards to carbonate. The concern is that over time the frequency and scale of low carbonate water will have broader corrosive effect in areas with upwelling cold water. Feely and others (2012) have estimated that the upward migration of aragonite and calcite saturation horizon is on the order of 1 meter per year due to CO2 inputs into the ocean.

I don't want to get into a critique of Cliff Mass (cliffmass.blogspot) critique on the Seattle Times article ( I'll just say I very much enjoy Cliff Mass' blog on weather and thought the Craig Welch Seattle Times article was extremely well done and researched.

However, as alarming as the Welch article was I found this graph very disturbing:

Zeebe and Zachos (2013) looked at the loading rate of CO2 into ocean water under current "business as usual" and compared it to their estimated rate for the Paleocene-Eocene Thermal Maximum (PETM). The PETM had CO2 levels and temperatures reflective of where we may be heading if we stay on the same CO2 path. In addition to the much warmer climate, the ocean consequences if we stay on the same path will be sharply different than that of the PETM; surface saturation for calcite would rapidly plummet to much lower levels than during the PETM. This would have a dramatic impact on ocean life. Yes it is alarming.


1 comment:

Elizabeth said...

Good job, Dan. Thanks.