Evaluation of abiotic stresses of temperate estuaries by using resident zooplankton: A community vs. population approach

摘要: Abstract By using permanently resident zooplankton, we assessed the ecological level (i.e. community and or population) that provides more in-depth indication of stress related to salinity temperature fluctuations in temperate estuaries. In semi-arid warm South Africa, Gamtoos estuary experiences a full gradient maintained by irregular but relatively frequent freshwater pulses, whereas Kromme is euhaline throughout its extent receives only occasional inputs when storage reservoir six km upstream overtops. Changes species evenness index Pielou abundances estuarine zooplankton were modelled against variations respective estuary, response individual populations provided information regarding variability. However most abundant i.e. Acartia longipatella copepod was not best predictor fluctuations. Conversely, study insights into potential vulnerability cold. Further, population exposed responses specific changes. We discuss pros cons designing indicators abiotic based on species, targeted level, needs considering frequency magnitude fresh water inflow an estuary. A suggestion use taxonomic group(s) (e.g. Copepods) better understand factors set estuaries rich/starved) until ‘one size fits all’ indicator found for