Detrimental effects of urbanisation on animal assemblages and a key ecological function persist across ecosystems

Context Urbanisation is pervasive across landscapes and seascapes and leads to the loss, degradation and fragmentation of many natural ecosystems and this has widespread consequences for animals and the ecological functions they support. While the impacts of urbanisation are understood for many individual coastal ecosystems in isolation, it is unclear how these impacts influence animal assemblages and ecological functions across different coastal ecosystems within the same landscape. Objectives We aimed to determine how urbanisation modifies fish and crustacean assemblages and the function of carrion consumption across multiple coastal ecosystems set within the same landscape in eastern Australia. Methods We sampled fish and crustacean assemblages in three distinct coastal ecosystems (estuaries, rocky headlands and surf zones) with baited remote underwater video systems and quantified rates of carrion consumption using scavenging assays. Results Urbanisation had negative effects on the richness and abundance of coastal fish and crustaceans and the ecological function of carrion consumption, and these impacts were almost always consistent across estuaries, rocky headlands and surf zones. Species richness and abundance were lowest at the most urbanised sites, whereas rates of carrion consumption were lowest at sites closest to urbanised areas, across all ecosystems. Conclusions We highlight the negative effects of urbanisation on coastal fish and crustacean assemblages, and a vital ecological function, and the consistency of these effects on distinct coastal ecosystems located within the same landscape. Managing the pervasive impacts of urbanisation on animal assemblages and ecological functions will, therefore, require targeted approaches that address the underlying impacts of urbanisation across multiple coastal ecosystems.