NZ Environmental Management was contracted by New Zealand Transport Agency to undertake a Freshwater Fish Survey, of the drain proximal to State Highway 10 bounding the Komutu Wetland, prior to maintenance works being carried out.

The purpose of this survey was to determine fish species present and make recommendations for the management of the works to achieve minimal impact to the aquatic habitat.  

Eight species of fish were caught or observed during the survey including five species of native freshwater fish; shortfin eel [Anguilla australis], longfin eel [Anguilla dieffenbachii], common bully [Gobiomorphus cotidianus], giant bully [Gobiomorphus gobioides] and inanga [Galaxias maculatus]. The introduced pest fish, Gambusia or mosquitofish [Gambusia affinis], were widespread and the estuarine cockabully or triplefin [Grahamina nigripenne] were confined to the saline influenced tidal reaches of both drains surveyed. Grey mullet [Mugil cephalus] were observed in low numbers in both drains.