The effect of ocean acidification on the benthic ecosystem
The increasing emission of CO2 to the atmosphere resulted in many problems related to climate change. However, a lot of this CO2 is taken up the worlds’ oceans, partly mitigating the problems caused by increased concentrations of CO2¨in the atmosphere. However, the uptake of CO2 has lead to a reduction in pH of about 0.1 pH levels compared to pre-industrial times. As atmospheric CO2 concentrations are projected to double over the next century, an addition decline in pH by 0.3-0.4 pH units is predicted. In coastal seas, the pH decline was shown to be an order of magnitude higher. This process is called ocean acidification (OA) and is now often referred to as “the other problem” as this process has important negative consequences for calcifying (e.g. coral reefs, coccoliths, foraminifera and bivalves) and and non-calcifying organisms (e.g. diatoms, nitrifiers, and heterotrophic bacteria). Research on the effects of OA focuses generally on the pelagic realm, while research on the effects of OA on the seafloor ecosystem is still in its infancy. Up to now, only three papers are available, and all of these papers suggest a negative effect of OA on benthic ecosystem functioning. However, the range of experimental evidence is too limited to draw general conclusion as yet.