The role of solid waste materials as habitats for macroinvertebrates in a lowland dam reservoir

Abstract

Because of the increasing anthropogenic pressure, the amount of solid waste discarded in water is growing considerably. It can affect aquatic organisms, modifying their distribution and abundance. This study was designed to investigate the effect of several types of solid waste (bottles, textiles, bundles of string, pieces of polythene and rubber) upon the taxonomic composition and biodiversity of macroinvertebrates inhabiting the near-shore zone (up to 1-m depth) of the Wloclawek Reservoir (the River Vistula, central Poland). The epifauna developing on these materials was compared with organisms living on natural substrata: bare sandy bottom (from which the waste was collected), macrophytes and sandy bottom overgrown by plants. The communities inhabiting the artificial substrata (except strings) were much more diverse (in terms of taxon richness, Shannon–Wiener index and evenness) than the surrounding bare sandy bottom. The biodiversity on the waste was similar to that found on the macrophytes and bottom among them, located nearby. The most suitable materials appeared to be bottles, providing shelters in their interiors. The artificial substrata differed considerably from all natural habitats with respect to taxonomic composition, though they were more similar to the macrophytes than to the bottom sediments. Furthermore, the variability among the assemblages developing on the particular waste objects, even of the same type, was much larger than that observed on the macrophytes, indicating the patchy nature of the former habitat. Thus, discarded waste can constitute alternative habitats for invertebrates, especially when natural substrata are unsuitable (e.g. sandy bottom), but they cannot fully replace natural substrata, such as plants, in their habitat-forming role in ecosystems.