Cascading effects of pollution across aquatic-terrestrial ecosystems

Aquatic and terrestrial ecosystems do not exist in isolation. In fact, the transport of resources and energy from donor ecosystems subsidizes a huge amount of consumer biomass in adjacent recipient ecosystems. These allochthonous resources (derived from different ecosystems) can be realised by living organisms, such as aquatic insects that are consumed by terrestrial predators like spiders, birds, and bats. If pollutants and contaminants in water influence aquatic organisms, cascading effects are expected through adjacent terrestrial environments. Pollution can reduce the abundance and diversity of less resistant organisms, leading to a reduced contribution of allochthonous resources to terrestrial consumers. Consequently, terrestrial consumers may decrease in abundance and diversity near polluted aquatic environments. However, pollutants can also increase the dominance of more resistant aquatic organisms. Both these effects can significantly alter the ecological networks and energy pathways between aquatic and terrestrial organisms, compared to preserved environments. This project will adopt modelling and field work in both temperate and tropical regions to investigate how aquatic pollutants alter the relationship between aquatic and terrestrial realms through modern diet tracing techniques, including complementary methods of compound-specific stable isotopes and consumers' gut content eDNA molecular analyses for the construction of consumer-resource networks.