Concerns are growing about the fragile state of Canterbury's high country lakes

A new scientific report reveals nutrients will have to drop significantly in Heron, Emily, Clearwater, Camp, Emma, Denny and Maori lakes.

The pollutants are coming from farmland, recreation and birds.

Environment Canterbury Science Director Dr Tim Davie says it's clear that the Ashburton lakes are at risk of becoming turbid, algal-rich and degraded.

He says none of them meets nutrient limits in the Land and Water Regional Plan.

A working party is looking at farming options, new sewage limits for Lake Clearwater village and working out the impact of birds.