The humble straw bale is an unlikely new tool for boosting whitebait stocks around the country, new research suggests.
Researchers at the University of Canterbury set things off, using the bales to create artificial habitats on degraded riverbanks where whitebait spawn.
Marine Ecologist Dr Mike Hickford says the areas where they do spawn could then be fixed and protected by using the bales.
"It occurred to us we could use them in a slightly different way where we could use them to find where fish would lay their eggs if the habitat was better.
The study was taken out on the Heathcote and Avon Rivers, in Christchurch, as the earthquakes dramatically changed the riverbanks.
"So they [the bales] become sort of a tool to go to these areas where we know the habitats are a bit degraded and knocked around and for whatever reason the banks aren't any good for the fish to lay their eggs on.
"By putting out these bales you could see the potential spawning sites, you could see where they [whitebait] would spawn if the habitat was good."
The bales can be used to help boost whitebait stocks in other spawning locations across the country, Dr Hickford says.
Newshub.
