Baywide water quality monitoring program
EPA has been monitoring water quality in Port Phillip Bay at six sites for over 30 years. This monitoring program was expanded for the duration of the Channel Deepening Project and continued, following its completion, from 2008 to 2011.
The expanded monitoring program included monthly samples at 11 sites across the bay and a wider range of parameters was tested for, including lead, mercury, arsenic and phytoplankton species.
To minimise the environmental effects on Port Phillip Bay from the Channel Deepening Project, a set of rules were developed to control when, where and how dredging could be done. Supporting these rules were 13 baywide monitoring programs that collected information on the bay’s health between 2008 and 2011. Amongst these, EPA has conducted its expanded water quality monitoring program and measured contaminant concentrations in fish of the lower Yarra River.
Lower Yarra fish study
EPA Victoria first investigated contaminant levels in recreational fish in 2005, which led to a more comprehensive study in 2006. Based on the results from the latter, a health advisory providing information for recreational fishing in the lower Yarra and Maribyrnong rivers about safety for human consumption was issued.
The 2009 Lower Yarra fish study determined whether contaminant levels in fish from the lower Yarra River had significantly changed since the last study in 2006, which would require a review of the health advisory.
It tested the levels of a large range of contaminants, including heavy metals such as mercury and arsenic, organic pesticides, hydrocarbons, dioxins and other compounds that may be found in fish caught in the lower Yarra.
The study found that the contaminant levels in fish sampled from the lower Yarra River remained essentially unchanged since 2006, and a review of the existing health advisory was not necessary.