De-intensify agriculture only way to save high country lakes

The declining state of Canterbury’s high country lakes shown in a new Ministry for the Environment report highlights that intensive agriculture should never have been allowed in these sensitive ecosystems, says Fish & Game New Zealand.

The newly released Ōtūwharekai/Ashburton Lakes lessons-learnt report outlines the ongoing deterioration of freshwater health in this network of wetlands and small to medium-sized lakes of national ecological significance.

“The alarming state of these outstanding ecosystems is despite the rural community going above and beyond to meet regulations, working to implement Farm Environment Plans and voluntarily adopting good management practices,” says Corina Jordan, Chief Executive of Fish & Game.

“But that was never going to be enough for this highly vulnerable area. Our concern is that the community are not being told what’s really needed to protect these sensitive natural environments, and that’s ultimately to return to extensive sheep-based farming systems. Farm Environment Plans and Good Management Practices were never going to be enough.”

The report shows elevated levels of nitrogen and phosphorus, with the lakes partly eutrophic, elevated sediment and nutrient levels, algae growth, and reduced clarity. None met the objectives in the Land and Water Regional Plan (LWRP) for the Trophic Level Index (TLI) score in the period between 2017 and 2021, and some are failing to meet national bottom lines.

This decline coincides with an intensification in farming land uses from around 1990 to 2010, involving increases in cattle numbers, fertiliser use, winter forage grazing, and vegetation change (from indigenous shrubs and tussock to shallow-rooted pasture grasses).

“The reality is that we’ve known for a generation that we can’t have this level of intensive agriculture in these sensitive environments without causing the significant deterioration captured in this report,” says Jordan.

“With these farming systems on Crown pastoral lease land, I believe it’s been irresponsible of our leaders, for both the environment and farmers, to have allowed the land use to intensify as it has.

“No one is winning. It’s bad for the environment, it’s bad for farmers in particular current extensive farmers as they get caught up in new regulatory requirements aimed at intensive agriculture, and it’s bad for New Zealand’s overall agricultural brand and social licence to operate.

“Now, we need to see responsible leadership and a conversation with the community and local government around de-intensification of agriculture in these high country lake environments. Solutions look like a return to extensive farming systems such as Merino systems that have low nitrogen and phosphorous inputs, support an integrated landscape with biodiversity,  and no irrigation.”