Southland District Council has received more than 200 submissions on a $7 million cycleway around the mountains. Many are from anglers against the route the trail will take.
Southland Fish and Game says the trail will go through the Mararora River catchment in the Eyre mountains.
Environmental planner Jakob Smyth says that is one of the best brown trout fishing areas in the world.
While Fish and Game is not worried about the rest of the trail, Mr Smyth says the gravel trail, which is three to four metres wide, will have a detrimental effect on fishing in that area.
However, cycleway project manager Mike Barnett says anglers want the Mararora Valley all to themselves and are being selfish.