Out of our depth

Dr Mike Joy believes the key to improving New Zealand’s waterways and natural environment is the power of the people. “My message at my public talks is, ‘Your rent for living on this planet is activism’. It’s become clear that if government changes anything, it’s when people push for change,” he says.

Birds eye view of a dry river bed.

“The science is clear, and my role is about public awareness and getting as much information as I can to the public about what’s going on.”

Mike, a freshwater ecologist based at the University’s Institute for Governance and Policy Studies, says the main issues are the intensification of agriculture and our failures in wastewater management.

A recent study found drinking water supplies in some parts of New Zealand have nitrate levels more than three times higher than a threshold level for colorectal (bowel) cancer risk.

“The nitrate pollution comes from dairy farming mostly,” says Mike. “Nitrate fertiliser is added to pasture and crops to accelerate plant growth. Much of it enters waterways either directly with rain and irrigation or through animal urine.”

Moving away from farming intensity is a single solution to multiple problems, he says.

“Decrease the number of cows and you reduce the loss of nutrients to waterways, you reduce methane, nitrous oxide, and carbon emissions to the atmosphere, you reduce pathogens that get into waterways, you reduce antibiotic and hormone use, meaning less of both in soil and waterways, you reduce the heavy metal contamination of soil, and you reduce the compaction of soils.

“Focusing on adding value and diversity will give us all a much better future.”

Another recent study has shown 74 percent of New Zealand’s native freshwater fish are threatened or at risk. This compares to 22 percent in the early 1990s.

“The legislation intended to protect biodiversity in New Zealand is neglected and largely ineffectual,” says Mike. “Our native fish are not covered by the Wildlife Act. The only species that the Freshwater Fisheries Regulations from 1983 protects is the grayling—and that went extinct 50 years earlier, in the 1930s.

“Others are protected except if you want to use them for human consumption or scientific purposes, which in practice translates to zero protection. Of our threatened native fish, including whitebait, longfin eel, and black flounder, seven of them are commercially harvested and exported.”

Mike says it’s the past 50 years where we’ve accelerated beyond our boundaries. “New Zealand’s clean green image is crucial to tourism and agriculture, and because we’ve gone backwards too fast and we’re so isolated, people haven’t caught up. It’s the value add to everything we export—and if we lose that, we never get it back.

“Our freshwater systems are in awful shape, and getting worse fast. Our grandchildren won’t be swimming in our rivers, and there won’t be native fish in them either, unless we make changes now.”