Western Port, in south eastern Victoria, is a large, semi-enclosed bay with significant ecological and social values.  However the landscape has been altered substantially by anthropogenic activities in the last century and is under increasing pressure from rapid urban growth.

A report consolidating knowledge of the Western Port environment identified threats to environmental assets and critical knowledge gaps, which included the need to understand threats from toxicants.  To address this, CAPIM sampled smooth toadfish (Tetractenos glaber) from areas within Western Port, Port Phillip, Andersons Inlet and Shallow Inlet over a two year period. Sites were selected to include some with known pollution inputs (impact) and others without (reference).  To determine fish health, general condition indices, morphological and biochemical measurements and histological evaluations were done.  Additionally, genome scans of single nucleotide polymorphisms (SNPs) using next generation sequencing were used to determine patterns of connectivity, levels of genetic diversity and tests for signatures of adaptive variation within toadfish populations.

Site specific differences were observed for several indicators and will be discussed in relation to measured water and sediment toxicant concentrations, and implications for the protection and improvement of the Western Port environment.