Does plankton diversity peak at intermediate salinities? Comment on Telesh et al. (2011)

Protistan diversity does peak in the horohalinicum of the Baltic Sea: Reply to Ptacnik et al. (2011)

“…Nevertheless, we welcome the critical suggestions of Ptacnik et al (2011) and concur with their opinion that calculation of e.g. smoothed rarefaction curves and accumulation curves for certain plankton groups would be useful.…”

“…ciliates) in certain areas (Telesh et al 2008). Ptacnik et al (2011) surmise that the peak in plankton diversity in Telesh et al (2011, their Fig. 2C) seems to stem largely from the peak in sampling effort.…”

“…at local or regional levels or as conducted by Olli et al (2011). Ptacnik et al (2011) question the validity of the richness patterns in Telesh et al (2011), which were largely derived from coastal sites, claiming that those are not representative of the open Baltic Sea. This may be true if the latter term refers to the deep-sea Baltic Proper, the plankton diversity of which is not well known, because HELCOM monitoring data for this region are restricted to dominant species.…”

“…We reassessed overall plankton diversity in the Baltic Sea, refined Remane's concept by showing its inapplicability to plankton, proposed a new 'protistan species-maximum concept' and dismissed the outdated viewpoint that the Baltic Sea is poor in plankton species (Telesh et al 2011). Ptacnik et al (2011), in their thoughtful Comment on our article concerning protistan diversity trends in the Baltic Sea, dispute that the analysis performed in Telesh et al (2011) allows conclusions regarding the pattern of plankton diversity along the freshwatermarine continuum. They particularly claim that our analysis is biased because species lists were pooled within salinity bands, which may create patterns that are due to methodology.…”

Environmental Impacts—Marine Ecosystems

“…Telesh et al (2011a, b) challenged Remane's concept by suggesting that protistan diversity does not decline but peaks at intermediate salinities of the horohalinicum. This idea was in turn questioned by Ptacnik et al (2011), who claimed that Telesh et al (2011a) derived their diversity patterns largely from coastal bays and lagoons, which are not representative for the Baltic Sea as a whole. The effects of climate-induced salinity shifts on plankton diversity thus remain a matter of debate.…”