The advent of extreme and swift climate change has led society to ask questions about the future not previously considered as serious considerations.
A few days ago the Year 12 Agribusiness class headed out to test the waters of the Taieri River armed with specialist environmental science equipment. After an introduction to the Taieri flood plain history from the Three Mile Hill viewpoint, we headed out to the Glen, Outram to begin testing at the first of six sites. Every student had the opportunity during the day to use each piece of equipment and record the data for the rest of the class.
The overall aim of the yearly project is to track the health of the river by testing numerous parameters that include dissolved oxygen levels, pH, temperature, chlorophyll-a levels, E.coli bacteria, nitrates, phosphates, clarity and salinity. With this growing body of data, one is able to consider the effects of climate change (now and in the future) and compare these data with the parameter requirements of the Brown trout as the (almost?) apex predator in that ecosystem. With late March water temperatures previously measured of around 17.5 degrees celcius at two sites and the knowledge that Brown trout can only spawn in temperatures 11 degrees and below in August/September, one can begin to imagine a future where this 150 - year old introduced species is no longer able to reproduce and survive in our rivers. In contrast, an early June trip yielded much cooler temperatures on a particularly cold day. On average though, the temperatures are still pushing the spawning limits at around 9.5 degrees.
Whilst the water-testing and sample collection is relatively easy (and fun) to accomplish, data analyses and interpretation is an entirely different matter. Students are now trying to make sense of the data by noting any obvious trends and statistically significant site parameter variations in order to produce a report about the long-term sustainability of the fish Otago locals love to lure!
(My heartfelt thanks to the boys for their excellent involvement and attitude throughout the day, and to Andrew Innes for loaning us his YSI parameter meter.)