Molekulare Mechanismen der Ionen- und pH-Regulation in marinen Fischen unter dem Einfluss der Klimafaktoren CO2 und Temperatur

The increase of atmospheric CO2 concentrations leads to progressive ocean warming and acidification. During exposure to elevated PCO2 marine teleost fish compensate for the extracellular acidosis by means of efficient ion and acid-base regulation, mainly in the anterior gut, the gill and the kidney. However, maintenance of a new steady state within body fluids may require higher regulatory efforts by transport mechanisms, stimulated further by ocean warming. Ion and acid-base transport components were analyzed on different functional levels in gill, kidney and anterior intestine of Atlantic cod (Gadus morhua) in response to temperature and CO2. The findings reveal species-, treatment- and tissue-specific adjustments of transporter capacities. Adjustments may also impose direct and/or indirect downstream effects, entailing possible physiological trade-offs, which have to be examined in the future. Together, the data represent a first step towards systemic models, fostering a mechanistic understanding of compensatory processes in a marine fish under elevated temperature and PCO2.