Fish

The Park’s wetlands support many species of fish and act as a nursery ground for some species found throughout Sydney Harbour.  A baseline survey conducted over 2007-2008 identified:

• 8 fish species and 1 crustacean species in freshwater habitats. The most abundant species were freshwater shrimp, followed by the introduced mosquito fish. Other species included the Short Finned Eel, Long Finned Eel, Flathead Gudgeon, Dwarf Flathead Gudgeon, Sea Mullet and Common Carp. The most abundant native fish were eels and gudgeons.
• 22 fish species and 3 crustacean species in estuarine habitats. The most abundant species were Glassfish and Glass Shrimp. Pacific Blue Eye, Silverbelly, Sandy Sprat and Toad Fish were the most common native species of fish recorded in the estuarine sections of the park. The introduced Yellowfin Goby was also recorded in some locations. The greatest diversity of fish was found within the tidal creeks.

The introduced mosquito fish Gambusia holbrooki is classified under legislation as a ‘noxious’ fish species, and poses a risk to tadpoles in the Park’s freshwater wetlands.  Stringent hygiene practices are implemented to prevent its introduction into the Brickpit, and an annual pond draining program is implemented in Narawang Wetland each spring to reduce its numbers ahead of the frog breeding season.