Research is underway on the barriers on the West Coast which are stopping young freshwater fish to travel upstream to feed grow into adult fish.
A number of species are in trouble because of man made barriers to fish passages.
DOC's looking at what can be done to free up those pathways in order for the freshwater wildlife to survive.
Freshwater science advisor to DOC Nixie Boddy talks to Jesse.
Whitebait Photo: SUPPLIED / Shelley McMurtie
