The organisation representing Southland anglers is calling on the dairy industry there to start farming smarter and have a softer impact on the environment.
Southland Fish and Game operations manager Zane Moss says both water quality and aquatic life in the region are suffering and anglers are deserting their traditional spots because of slime and algae in the water caused by nutrient leaching.
Mr Moss thinks part of the solution is less intensive farming. He says an emerging area of research suggests some farms with less intensive systems are more cost effective from an individual farmer's perspective.
"So guys that are running, say, 2.6 cows per hectare rather than 3.6 with lower inputs, less use of urea and so on, less supplementary feed from external sources, they're getting greater per cow production, stock live longer and so on."
Mr Moss says in some situations these farmers are more profitable, and in a lot of situations they are equally profitable.
He says the fencing of significant streams that Fonterra is having its farmers carry out is still not enough and farmers need to start thinking about off-paddock wintering and how they feed their stock.
Mr Moss says Southland has relatively wet saturated soils over the winter and using fodder crops to support cows through that damages soils and causes a lot of nutrient loss.
He says moving away from a brassica crop for winter is likely to be another requirement.