Surviving an Invasion: Characterization of One of the Last Refugia for Artemia Diploid Parthenogenetic Strains

Abstract

The eradication of native populations of Artemia by the invasive A. franciscana constitutes one of the most conspicuous examples of biodiversity loss in hypersaline aquatic environments. Detailed information on the biological mechanisms that are supporting the invasion process, as well as on the importance of environment variables, is of paramount importance if adequate measures aiming at preventing the eradication of native strains are to be successfully implemented. Although the role of environmental stress in benefiting invasions has recently been documented, there seems to be little information on the characterization of environments where invasion is delayed or has failed altogether. Given that both the biotic and abiotic parameters of salt ponds within the Aveiro’s salinas complex (Portugal) presently occupied by A. franciscana have already been thoroughly characterised (Vieira and Bio, Journal of Sea Research 65:293–303, 2011), we will compare the same variables to those measured in an artisanal salina from the same complex, where native Artemia still occurs. Since there is no indication of salt ponds where both the native and invasive species co-occur, we hypothesise that explicit differences in environmental factors (e.g. salinity, temperature, pH, alkalinity, dissolved oxygen availability or nutrient concentrations) would help justify the observed distribution pattern of both Artemia species.