Monday, 26 September 2016

Mopping up spilt milk: pollution in the New Zealand dairy sector

It's been slow to dawn on New Zealanders, but for a country that prides itself on a '100% Pure' image our environmental pollution record is fairly appalling - and shows few signs of alleviation. Politicians who point to the large percentage of the nation's electricity generation coming from renewable sources, not to mention the slow but sturdy growth in hybrid vehicles, are completely missing the point: it has been claimed that over half of New Zealand's greenhouse gas emissions emanate from agri business.

Although the quantity of sheep in the country has plummeted from a 1982 peak of around 70 million to less than 30 million last year, cattle numbers continue to rise. There are about 3.6 million livestock on beef farms and circa 6.5 million dairy cattle. The latter sector generates twenty percent of New Zealand's exports and seven percent of its GDP, so it forms a substantial component of the kiwi economy. But with plans to double the country's dairy production by 2025, the term 'sustainable development' appears to be, well, unsustainable.

Since cattle create as much waste product as fourteen humans, it's not difficult to imagine some of the more obvious forms of dairy pollutant, smell and all. As New Zealand dung beetles are primarily forest dwellers there have been trials of introduced dung beetle species to help clean up the waste, with a reduction in nitrous oxide emissions from the soil and a lowering of cattle disease as side benefits. However, pastoral poo is only one element in the catalogue of pollutants caused by dairy farming.

Last summer I was taken to an outdoor swimming hole not far from Wanganui, consisting of a rectangular concrete-lined pool situated on the edge of a forest. I was informed that children had swam there until a decade or so, but no more: several signs warned that the water is contaminated and no longer safe for humans. This story has been repeated throughout New Zealand, with agriculture being by far the most common culprit. It isn't just artificial environments that have this problem; reports suggest that within the past twenty years about two-thirds of monitored swimming areas within rivers have become too polluted. And that's just for people; there's far less concern for the effects on river fauna and flora.

Although environmentalists have been issuing warnings for years, not enough has been done to alleviate this problem. Last month approximately five thousand inhabitants of Havelock North were taken ill due to tap water contaminated by campylobacter. The source was a series of bores which the director of the Infectious Diseases Research Centre at Massey University, Professor Nigel French, put down to pollution from sheep and cattle. Sources of contamination could include carcases of dead livestock, as well as faecal matter getting into waterways that provide the source of unchlorinated - and therefore at risk - tap water.

In fact, the outbreak appears to be the tip of the iceberg. Despite some hundreds of cases of illegal effluent discharge brought against New Zealand farmers each year, many more escape prosecution. It has to be said this seems to be a regular occurrence for the Ministry for Primary Industries, judging by the recent reports of their waiving prosecutions for commercial fishing vessels caught flouting bycatch and dumping laws. Turning a blind eye seems to be the order of the day when it comes to protecting food production - or at least the food producers. This philosophy seems to be driven by those who clearly have little understanding of the complexity - and at times fragility - of food webs. Not so much short-term thinking as profound myopia!

In addition to the organic matter there are chemical pollutants that can find their way into water supplies situated close to farms. Since the 1990s, the New Zealand Ministry for the Environment has been monitoring ground water for nitrates and has found levels substantially above those recommended for drinking water. Although chemical fertiliser has been blamed in addition to livestock effluent, environmental mapping suggests the latter is the primary cause, since the polluted areas heavily coincide with the widest-scale dairy production.

As well as polluting waterways dairy farmers have also been caught stealing billions of litres of water each year from rivers and aquifers, especially in the Canterbury region. Whilst not a form of pollution per se, this is obviously somewhat lacking in the environmentally-friendly stakes. The deforestation of low-lying plains for cattle grazing is also a source of pollution, as the lack of tree roots, besides allowing greater flooding, can generate increased run-off into rivers. This polluted water can lead to algal blooms, lowering oxygen levels and so endangering freshwater fish. That might not sound of any great concern except to diehard anglers, but for any whitebait fans, four of the five Galaxiidae species whose young form this delicacy are now said to be threatened.

The systematic destruction of forests to make way for pastoral land use has been repeatedly raised as a concern not just by environmental organisations but by the New Zealand Ministry of Agriculture and Forestry (MAF) itself. Their 2006 report claimed close to half a million hectares of the nation's forests were at risk of conversion to land for cattle grazing.

In addition, overseas forests are also affected: since 2008 the amount of palm kernels imported into New Zealand as a dairy cattle feed supplement has doubled to over 2 million tons per annum. This accounts for about twenty-five percent of global production and comes at the expense of destruction of rainforests in nations including Indonesia and Malaysia. Although the state-owned farm company Landcorp Farming Ltd is in the process of moving to a different supplement over the next year or so, the dairy giant Fonterra has not announced similar intentions. What's wrong with those guys: a surfeit of Milton Friedman in their formative years?

Having covered solids and liquids, it's time to move on to gas. As I've mentioned on various occasions, methane is a primary greenhouse gas. It was therefore shocking to discover that per capita, New Zealand has the greatest annual methane emission rate worldwide, accounting for over forty percent of the country's greenhouse gas emanations. The methane emission from dairy cattle alone has continually increased over the past quarter century, although the amount reported varies from ten percent to a whopping fifty percent or so. Perhaps that's not surprising, considering cattle can each generate up to 500 litres of methane per day!

There is some recent cause for hope, with various trials under way to reduce bovine emissions. These range from vaccination to selective breeding to diets bases on forage rape, with the latter showing that the change in feed affects fermentation - and therefore reduces methane production - in sheep. However, it wouldn't hurt to see the Government funding more research in this matter: one widely-reported paper last year was Massey University's The New Zealand Dairy Farming: Milking Our Environment for All its Worth, which received much criticism from the dairy sector when it was revealed to consist primarily of a student thesis.

It's very easy to become depressed with such deleterious effects coming from just one sector. Of course no nation can afford to rest on its laurels: we cannot turn the clock back. The halcyon image of bucolic ruralism is a myth perpetrated by those who have never worked on the land and farmers deserve the benefits of modern technology in their work as much as anyone. The development of sophisticated tools and software can aid the dairy sector in preserving the environment. as long as there is enough public money to support this eco-friendly research. But Government funding for this type of sustainable development appears to be sadly lacking. Doesn't it make sense that those who run God's Own Country should try a little harder to prove that the 100% Pure tagline isn't just marketing spin?