Structure and dynamics of gastropod communities in highly transformed aquatic environments colonized and uncolonized by globally invasive Potamopyrgus antipodarum (Gray, 1843)

Abstract

We examined the association between habitat parameters and gastropod communities across a number of freshwater ecosystems, whose biodiversity has been affected by increased mining activities over decades. Reservoirs inhabited by the New Zealand mud snail (Potamopyrgus antipodarum (Gray, 1843)) exhibited different abiotic conditions than waterbodies that were not, such as higher salinity indicators (max. conductivity 13400 μS/cm, TDS 7700 mg/l and chlorides 7200 mg/l), and degraded water quality. In such water bodies P. antipodarum density was high (max. 23686/m2). Further, invaded waters were inhabited by less diverse gastropod communities than reservoirs without P. antipodarum. The invader has established reproducing populations and were the dominant species (D 87.53%), or formed mono-specific assemblages, in the reservoirs. Our results indicate that P. antipodarum occurred in habitats whose conditions are unfavorable or less preferred by other species, such as those with high conductivity, and high concentrations of chlorides and calcium. Since this snail is known to inhabit water bodies with degraded water quality, we assumed that along with the progressing development of industries worldwide, this species will continue to spread to industrial areas and will inhabit increasing numbers of anthropogenically affected water environments. Our study contributes to the global understanding of the mechanisms involved in successful establishment in waters by P. antipodarum, and is especially novel in addressing its occurrence in anthropogenically created ecosystems. Our results showed that human impact is the cause of the trend in P. antipodarum populations, and compared habitats from the perspective of both abiotic parameters and community structure. Human activities can have a significant impact on water quality that can result in the permanent establishment of P. antipodarum populations, especially when the environment is not favorable for the native species.