A. Steckbauer, L. Ramajo, I.E. Hendriks, M. Fernandez, N. Lagos, L. Prado, C.M. Duarte
Frontiers in Marine Science, 2(49), (2015)
Ocean acidification (OA) and hypoxic events are an increasing worldwide
problem, but the synergetic effects of these factors are seldom
explored. However, this synergetic occurrence of stressors is prevalent.
The coastline of Chile not only suffers from coastal hypoxia but the
cold, oxygen-poor waters in upwelling events are also supersaturated in
CO2, a study site to explore the combined effect of OA and
hypoxia. We experimentally evaluated the metabolic response of different
invertebrate species (2 anthozoans, 9 molluscs, 4 crustaceans, 2
echinoderms) of the coastline of central Chile (33°30′S, 71°37′W) to
hypoxia and OA within predicted levels and in a full factorial design.
Organisms were exposed to 4 different treatments (ambient, low oxygen,
high CO2, and the combination of low oxygen and high CO2) and metabolism was measured after 3 and 6 days. We show that the combination of hypoxia and increased pCO2
reduces the respiration significantly, compared to a single stressor.
The evaluation of synergistic pressures, a more realistic scenario than
single stressors, is crucial to evaluate the effect of future changes
for coastal species and our results provide the first insight on what
might happen in the next 100 years.