Dr Mike Joy is a freshwater ecologist at Victoria University of Wellington. As a scientist he works in the field, studying freshwater organisms and the complex relationships they have with the aquatic environment. As a science communicator however, Mike has become an active participant in one of New Zealand most controversial issues; the nitrate pollution of New Zealand’s freshwater.
On this podcast, Mike discusses the issue in depth, tracing the path of nitrogen from the fertiliser factory, through the industrialised farm and into the river network, highlighting the increasingly detrimental impacts it has on ecosystem health as it accumulates there. However, it is on the subject of setting nitrate limits and enforcement where this issue truly becomes controversial.
As a member of the Science and Technology Advisory Group, set up by the Ministry for the Environment, he and other scientists have recommended nitrate limits for our rivers and drinking water supplies. However, if the nitrate limits recommended by this group of scientists were to be adopted and enforced, it could spell the end for industrial dairy farming in some of New Zealand’s largest dairy producing regions. As a result, an unavoidable conflict between protecting the environment and protecting the economy emerges.
What may prove to be non-negotiable however, is human health. The link between nitrate and colorectal cancer is an existing debate within the nitrate issue. However an even newer discovery; the emerging causal relationship between nitrate consumption and birth defects in new born babies, could have the potential to tip the balance of public opinion once and for all. So to discuss these emerging health issues, I interviewed Dr Tim Chambers, a leading public health researcher from the University of Otago.