The Sydney region has been modified by urbanisation and human activities. This has resulted in a loss of ecosystem integrity and consequently degraded water quality in aquatic environments. The impact on these aquatic environments has affected the abundance and diversity freshwater invertebrates across Sydney.

Some areas are so degraded that few freshwater invertebrates remain. Other areas contain only the most tolerant species. However there are still many locations around Sydney that have healthy ecosystems with a high diversity of freshwater invertebrates including species sensitive to disturbance.