Almost half NZ's fish species are diadromous, meaning that they regularly migrate between fresh and salt water. This makes estuaries an important highway for these fish.

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Five species of threatened fish have been seen in the catchment: longfin eel, giant kokopu, shortjaw kokopu, mudfish, and lamprey. The first three probably use the estaury for feeding and during migration. Whitebait probably spawn in the estuary and recreational whitebaiters use the estuary.

Black flounder, estuarine star gazer, grey mullet, and kahawai, are present, along with other coastal fish, including:

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Yellow eyed mullet (juvenile/adult/resident)
Shortfin eel (juvenile, adult)
Koaro (juvenile)
Torrentfish (juvenile)
Banded kokopu (juvenile)
Common bully (juvenile)
Giant bully (resident)
Redfin bully (juvenile)
Common smelt (adult/juvenile)