Acute salinity tolerance of the freshwater mussel Westralunio carteri iredale, 1934 of south-west Western Australia

Klunzinger, M.W., Beatty, S.J. and Lymbery, A. (2010) Acute salinity tolerance of the freshwater mussel Westralunio carteri iredale, 1934 of south-west Western Australia. In: 17th International Congress of Unitas Malacologica, 18-24 July 2010, Phuket, Thailand.

Abstract

Salinity is a major threat to the conservation of freshwater biota in many ecosystems of Australia, especially in south-western Western Australia (WA) where salt has impacted 9 of 17 (53%) freshwater river basins. Freshwater macro-invertebrates are sensitive to changes in salinity, which is a major threat to their survival. The degree to which salinisation affects particular species has not been thoroughly investigated in Australia. Westralunio carteri Iredale, 1934 is the only freshwater mussel species found in southwestern WA. It has been listed as Vulnerable on the International Union for the Conservation of Nature Red list of Threatened Species due to population decline resulting from increasing salinisation of and anthropogenic threats to waterways of its natural habitat. In this study, we perform two experiments to test the acute lethality of varying salinity concentrations (0, 1, 2, 3, 4, 5, 10, 15 and 20 g/L) for W. carteri to quantify sensitivity. Logistic regression analysis indicates that W. carteri has a salinity LC50 value of 3.06 g/L and an LC95 of 4.06 g/L. Salinities of 4 g/L or more were lethal to 100% of the mussels tested.