The state ferry Columbia now has six months of data since last October when it began testing the waters for acidity from Southeast Alaska across the entire Province of British Columbia to Bellingham, Washington.
It is part of an unprecedented Alaska/Canada project to learn how increasing ocean acidity affects regional fisheries.
“The fantastic thing about this vessel is it’s going from Bellingham to Skagway and back every week. That’s a 1,600-kilometer run. Nowhere in the world is there a ferry system that’s outfitted with CO2 sensors that’s running that scale of a transit. This is really exciting.”
Wiley Evans is with the Canadian Hakai Institute and the technical lead in the program.
His team rigged the 418-foot ferry to suck up water samples while it is under way.
The samples are measured automatically for oxygen, temperature, salinity and carbon dioxide. The CO2 levels indicate the acidity of the water.
“What we’re after is trying to understand the time and space patterns in surface ocean CO2 chemistry near shore. In this area, it’s extremely data-poor.”
The project’s mission is to understand how ocean acidity levels change seasonally, and where there are hot spots or refuges from corrosive waters.
Off kilter acidity makes it harder for marine creatures – and the micro-organisms they feed on – to form shells, among other things. The information can help scientists estimate the rate at which acidification is occurring in near-shore waters.
Preliminary data point to an extremely variable seascape in which the surface water is primarily corrosive in fall and winter, representing the most vulnerable time of year for species sensitive to ocean acidity.
When spring arrives, two primary factors create a change: the spring phytoplankton bloom removes CO2 from the water through photosynthesis, and the water gets warmer making conditions more favorable for shell production.
The Columbia ferry data is uploaded daily to the Alaska Ocean Acidification Network website.
Major studies show the southeast and southwest regions of the Gulf of Alaska will take the hardest economic hits from increasingly acidic waters.
Laine Welch, Alaska Fish Radio, 14 June 2018. Text and audio.
