The Swimming Performance of Atlantic Cod
Melzner, F., Gobel, S., Langenbuch, M., Gutowska, M.A., Portner, H.-0. and Lucassen, M. 2009. Swimming performance in Atlantic Cod (Gadus morhua) following long-term (4-12 months) acclimation to elevated seawater PCO2. Aquatic Toxicology 92: 30-37.
To rectify this situation, Melzner et al. maintained a group of Atlantic Cod (Gadus morhua) for four months in a re-circulating aquaculture system of 15 cubic meters volume at an atmospheric CO2 partial pressure of 0.3 kPa (~3,000 ppm) and another group for twelve months at a CO2 partial pressure of 0.6 kPa (~6,000 ppm), after which the fishes' swimming metabolism was investigated in a swim-tunnel respirometer, and tissue samples of their gills were taken for various chemical analyses, including gill Na+/K+-ATPase capacity, which serves "as a general indicator for ion regulatory effort." So what did they find?
The six German scientists report that "motor activity in adult Atlantic Cod is not compromised by long-term exposure to water PCO2 levels of 0.3-0.6 kPa," which are "scenarios exceeding the 0.2 kPa value predicted for surface ocean waters around the year 2300 (Calderia and Wickett, 2003)."
In light of what they learned from their study, Melzner et al. conclude that "adults of active fish species with a high ion regulatory capacity [which is employed to eliminate metabolic CO2] are well equipped to cope with prospected scenarios of global climate change," even those far beyond what could likely be produced by the burning of all fossil fuels in the crust of the Earth.
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