Protected and un-protected urban wetlands have similar aquatic macroinvertebrate communities: A case study from the Cape Flats Sand Fynbos region of southern Africa

Abstract

Rapid urbanisation has led to major landscape alterations, affecting aquatic ecosystems' hydrological and biogeochemical cycles, and biodiversity. Thus, habitat alteration is considered a major driver of aquatic biodiversity loss and related aquatic ecosystem goods and services. This study aimed to investigate and compare aquatic macroinvertebrate richness, diversity and community structure between urban temporary wetlands, located within protected and unprotected areas. The latter were found within an open public space or park with no protection or conservation status, whereas the former were inaccessible to the public and had formal protected, conservation status. We hypothesised that; (1) protected urban wetlands will harbour higher aquatic macroinvertebrate biodiversity (both dry and wet) as compared to unprotected urban wetlands, and (2) that the community composition between the two urban wetlands types will be significantly different. Contrary to our hypothesis, our results revealed no major differences between protected and unprotected urban wetlands, based on the measures investigated (i.e. taxon richness, Shannon-Weiner diversity, Pielou's evenness and community composition) during the dry and wet phase. The only exception was community composition, which revealed significant differences between these urban wetland types. These results suggest that human activities (potential littering and polluting) in the unprotected urban wetlands have not yet resulted in drastic change in macroinvertebrate richness and composition, at least from the dry phase. This suggests a potential for unprotected urban wetlands suffering from minimal human impact to act as important reservoirs of biodiversity and ecosystem services.