Species richness of crustacean zooplankton and trophic structure of brackish lagoons in contrasting climate zones: north temperate Denmark and Mediterranean Catalonia (Spain)

Abstract

We sought to identify environmental factors influencing crustacean zooplankton species richness in brackish lagoons and to elucidate whether crustacean zooplankton species richness and trophic structure of brackish lagoons differ among two regions with contrasting temperatures. We sampled 35 and 42 brackish lagoons (salinity ranging from 0.3 to 55) in Mediterranean Catalonia (NE Spain) and northern-temperate Denmark, respectively. No significant differences were found in total crustacean zooplankton species richness or cladoceran richness between the climatic regions. Calanoid richness was higher in Denmark than in Catalonia, while cyclopoid richness was higher in Catalonia. Salinity was the most important variable associated with zooplankton species richness in both regions, richness of total zooplankton species, cladocerans and cyclopoids being negatively related with salinity. In both regions, a shift occurred from dominance of large filter feeding cladoceran species at low salinities to copepods and small cladoceran species at higher salinities. Cladoceran richness increased with increasing total phosphorus, but was not influenced by total nitrogen or chlorophyll-a. Trophic structure in Mediterranean brackish lagoons showed a more pronounced seasonal variation than in north temperate brackish lagoons. Our results imply that the indirect effects of climate warming, such as changes in salinity and hydrology, will have a larger impact on brackish lagoon ecosystems than the increase in temperature per se.

Ecological impacts of global warming and water abstraction on lakes and reservoirs due to changes in water level and related changes in salinity

“…from freshwater to brackish levels) its effects may in some cases override all other environmental and pressure factors such as temperature or eutrophication, as shown for zooplankton (Brucet et al, 2009). This is supported by recent studies of streams in the USA where conductivity proved to be one of the most important stressors associated with biological degradation (Vander Laan et al, 2013).…”

“…In addition, elevated salinity can reduce the zooplankton growth rate due to osmotic stress in salt-sensitive taxa (Table S3). Similarly, in Spain and France, salinity appears to be the main environmental factor structuring the zooplankton and invertebrate communities in lakes and ponds (Green et al, 2005;Boix et al, 2008;Waterkeyn et al, 2008;Brucet et al, 2009). Not only Mediterranean regions suffer from increased salinity due to climate change.…”

“…However, increases in salinity cause a decrease in the densities of most organism groups due to osmotic stress, as shown by the literature review. For zooplankton, salinity may reduce the population growth rate of the keystone species Daphnia (Bezirci et al, 2012), which becomes replaced by copepods, rotifers and small cladocerans at higher salinities Brucet et al, 2009). …”

Zooplankton characterisation of Pampean saline shallow lakes, habitat of the Andean flamingoes

“…Derry et al (2003) found that in Canadian shallow lakes with chloride waters, B. plicatilis and the hapacticoid copepod Cletocampus sp., were the dominant species. However, it cannot be claimed that some abundant species such as Moina micrura and Metacyclops mendocinus should be considered indicators of a narrow range of salinity or a limited ionic concentration because they generally show a relatively wide range of tolerance (Rzóska, 1961;Alonso, 1996;Sterza and Fernández, 2006;Santangelo et al, 2008;Brucet et al, 2009).…”

<em>Bosmina (Eubosmina) coregoni</em> Baird, 1857 (Crustacea, Branchiopoda, Anomopoda): New planktonic invader in the Iberian peninsula

“…Apart from Northeastern Europe (e.g. Kernan et al, 2009) it was mentioned in Poland (Kuczynska-Kippen, 2006;Adamczuk, 2009), Germany (Nauwerck, 1991;Hofmann, 1996;Straile & Müller, 2010), Denmark (Brucet et al, 2009), Belgium (Malbrouck et al, 2005) and in Northern Italy (Margaritora, 1983). In the Iberian Peninsula B.…”