Table 1.

Sampling site description.

	Site name	Description
A	Morrel bridge	High density urban developments; high watercraft usage; Queens Bridge Drain located around 950 m upstream; deep, wide channel of salt and fresh water
B	Gardeners creek	Completely channelized section of Gardiners Creek; extremely receptive to rainfall events within the catchment; No tidal effect; High density industrial and residential areas upstream of site; no watercraft activity; surrounded by recreational/sporting grounds
C	Hawthorn main drain	Major urban stormwater drain. Collects stormwater inputs from high density industrial and residential areas; no watercraft activity
D	Abbotsford	Shallow fast-flowing riffled section; high density industrial and residential developments with recreational parklands; predominantly fresh water
E	Dights falls	Site ~20 m upstream of weir; surrounded by parklands; no tidal influence; minimal watercraft; Merri creek junction just upstream; Eastern Freeway crosses Merri Creek just U/S of Merri-Yarra junction
F	Kew	Low density industrial, medium level residential developments; minimal watercraft activity; no tidal affect; fresh water