Preliminary study on the effect of natural acidification on meiofaunal communities in sandy substrates

Abstract

In recent years, research on ocean acidification in naturally acidified systems (CO₂ vents) has increased, but very few have taken into account the meiofaunal communities living in sandy substrates, despite their importance as bioindicators. Therefore, the aim of this work is to carry out a preliminary study of the meiofauna associated with sandy substrates in the acidified system of Fuencaliente (La Palma, Canary Islands), which includes coastal lagoons with very extreme environments. The results obtained on the basis of meiofaunal abundance confirm a significant change in the meiofaunal communities in these coastal lagoons. We found an increase in bioindicator taxa of altered environments: oligochaetes, nematodes, copepods and, to a lesser extent, ostracods and acarids, with xenacelomorphs being the only group with a clear decrease in abundance, the most affected by natural acidification. All this indicates a clear alteration in the composition of the meiofaunal communities due to the extreme acidification of the seawater in the coastal environment of La Palma.