Louise Cullen - BBC News NI agriculture and environment correspondent
Nature in Northern Ireland is under "unsustainable" pressure and action is needed "urgently and decisively" to protect and restore the environment, a watchdog has said.
The Office for Environmental Protection (OEP) has published a review of the drivers and pressures affecting biodiversity in Northern Ireland.
The principal pressures it identifies are land use change and pollution, closely linked to agricultural intensification.
It says government policies on nature recovery and nutrient management must be implemented to help address the challenges.
The OEP has prioritised three areas for action:
Excess nutrients from fertiliser and animal waste in farming and from sewage are the main forms of pollution which are having an impact.
The report also finds waste management, resource extraction, urban development and chemical pollution are playing a part.
Research suggests Northern Ireland has lost 50% of its biodiversity based on a 1970s baseline, with ecosystems like rivers, lakes and other freshwater bodies also failing to meet good or high ecological status.
The OEP's chief scientific officer Robbie McDonald said it had examined pressures on the environment in Northern Ireland over generations.
"The very, very visible sign of deterioration has been in Lough Neagh," he said.
"But beneath the surface and across all of the waterways and land of Northern Ireland, this process has been going on for decades.
"So our contribution here is to pull together all of that evidence about the priority species and habitats we have here and to look at the factors that have led to their decline."
The report says the agri-industry is "making unsustainable demands on the land" and that the nutrient surplus is also unsustainable for the environment.
The chairman of the OEP Dame Glenys Stacey said nature underpinned the Northern Ireland economy and so protecting the natural environment was fundamental to achieving economic and social goals.
"More and more has been demanded of the environment over many years, and it is now clear that more pressure has been applied than the land and water can bear," she said.
"Government must act urgently and decisively, not only to reverse a lifetime of environmental degradation and to restore the biodiversity of Northern Ireland's habitats and species, but also to ensure a sustainable agri-food industry and wider economy.
"Failure to do so risks a heavy toll on the prosperity and well-being of future generations."