The findings of a recent study on the quality of freshwater in New Zealand have drawn a dismal picture. The study came to the conclusion that E. coli is making its way through three quarters of the land and into rivers at levels that are greater than what is permitted by national rules.
A survey that was funded by the organization Our Land and Water, which is supported by the government, investigated the ways in which rivers, lakes, and estuaries are polluted by four major contaminants. One of these contaminants is E. coli, which is a bacteria that may cause serious sickness and is present in the intestines of multiple animals and humans.
The difficulty that New Zealand experiences in getting pollutant levels down to a level that is in accordance with the guidelines that are specified in the National Policy Statement for Freshwater Management is brought to light by this.
According to Ton Snelder, director of LWP, a business that was involved in the creation of the research, “the big picture that we see in terms of water quality is the impact of agriculture, which is quite ubiquitous because agriculture occupies approximately 35% of our total land use.”
Other land uses, in particular urban land use, can also have quite a large impact on water quality, he said. “There are other land uses in particular that can have this impact.”
In addition to E. coli, the report analyzed the levels of nitrogen, phosphate, and sediment at 850 water monitoring sites located all throughout the country. It also modeled the potential impact that these contaminants could have on New Zealand’s 650,000 river segments, 961 lakes, and 419 estuaries. It is common practice to assign harmful quantities of nitrogen and phosphorus to farming outputs, such as cattle urine, despite the fact that these elements are naturally present in soil. Sediment is another naturally occurring pollutant that can reach harmful levels due to human-caused erosion as well as the usage of land for agricultural and urban use for environmental purposes.
Based on the investigation, it was decided that in order to comply with national laws, significant reductions of at least one of the four pollutants were required in almost all regions of the country. The data from the research were used to construct maps that illustrate the influence that humans have had on rivers. They reveal that the west coast of New Zealand’s South Island, which is sparsely inhabited, has low levels of the toxins. Some regions, such as Canterbury, which is known for its extensive dairy production, and Auckland, which is the largest metropolis in the country, have been found to have elevated levels of either nitrogen or E. coli.
To improve the quality of freshwater, it is the responsibility of local authorities to reduce pollution. These councils are also expected to manage farms and urban areas. When farmers use less fertilizer and make sure that bovine effluent from dairy sheds does not run into waterways, nitrogen and phosphorus levels in waterways can fall, according to Richard McDowell, a lead scientist at Our Land and Water and a professor at Lincoln University.
According to McDowell, a change in land use, such as shifting from dairy farming to forestry or crop farming in areas where it is appropriate, has the potential to improve water quality. This is in recognition of the fact that environmental and social concerns are coexisting. Farmers have pointed the finger at the high number of livestock farms that have converted to forestry as the cause of rural unemployment in recent years.
In New Zealand, there have been a few swimming places that have been closed off owing to water contamination. This is not related to the study either. Recent investigations have revealed that human excrement have been discovered in the waters at Corsair Bay, which is a well-known swimming spot in Christchurch. A sewage line in Auckland that had ruptured near the Hauraki Gulf was responsible for the release of raw sewage into the harbor for several weeks before the problem was temporarily resolved. A “boil water notice” has been in effect since the middle of September in certain areas of the upscale mountain town of Queenstown. This is because of an outbreak of cryptosporidium, which is a pathogen that can cause the symptoms of diarrhea and stomach cramps. The most common source is feces, either from humans or animals.