When it comes to tongue waggin’ and gum flappin’ with anyone interested in monitoring creek waters, the discussion may inevitably lead to bug collection – the spineless ones. You may recall from our last periodical about how we collect them, preserve them and send them off to a laboratory to have them identified by a Taxonomist. I’d like to share with you how these critters relate to the water we drink, use, and sport in.
First though, I’d like to share a short story about a dying breed – the Taxonomist: one who studies the classification of organisms. The story evolves from a murder case where the time of death was at issue. A taxonomist, the forensic entomologist type, determined the time of death was established by a particular bug found in the decaying body of the deceased at the time of examination. Forensics - scientifically proven! The accused was sentenced for the crime based upon opportunity at the time of death. Irrefutable evidence?
Not so, claimed the defence. Another more experienced taxonomist was called to testify whereby evidence was submitted that the first taxonomist misidentified the very same bug thus altering the time of death considerably. The moral: good taxonomists are indeed a dying breed, and: bugs can tell us a lot.
For many years now scientists have determined globally that those little wiggly things living in water are a good indicator of watershed health because they live in water for all or most of their life, stay in areas suitable for their survival, are easy to collect, differ in their tolerance to amount and types of pollution, often live for more than one year, have limited mobility, and are indicators of environmental condition. They are a link in the aquatic food chain.
We learn from the experts that these bugs include insect larvae- something familiar to fly fishers, leeches, worms, crayfish and shrimp, clams and mussels, and snails. In short – an entire community that is affected by local changes in water quality. Some are capable of tolerating higher loads of pollution than others. Thus if the pollution is severe, or is moderate but sustained over time, the whole community structure may simplify in favor of tolerant species. Although the abundance of certain species may change, diversity and species richness decreases. By assessing indicator species, diversity, and functional groups of critters, it is possible to determine water quality over time whereas water analysis provides information only at the time of sampling.
So, what kind of bugs do we find in Burton’s creeks? Flies. Of a raw count of 300 some bugs collected from each of the three creeks, the larvae of Mayflies, Midgeflies Stoneflies Sandflies
Caddisflies and a few Water Mites account for about 98 per cent, more or less, from each creek. Plus a few water mites, beetles, midges and worms. Is that good or what? Environment Canada’s CABIN (Canadian Aquatic Biomonitoring Network) analytical tools analyses our samplings and compares the results to a pristine watershed, suggesting that Burton’s creeks during 2009 and 2010 were relatively unstressed. However, I should stress that these preliminary results are not inclusive of all data collected and that future conditions are subject to changes as a result of human activity within the sheds.
Is it safe to say then that area creeks are in pristine condition? Without scientific data, there is no way of knowing for sure. However, with respect to samples of drinking water obtained from various surface sources, the presence of e. coli and fecal coliform has been confirmed. This is not to say that these surface sources are either pristine or unhealthy since the presence of bacteria and viruses occur naturally, especially during spring runoff (freshet) and extended periods of heavy rains.
In honor of the abundance of Mayflies in our waters, I would like to end this session with some fast facts: one of the oldest accounts of Mayfly biology was published in 1675; an unfortunate fact that the genus of mayflies, common in almost all freshwater habitats, is now extinct in the Netherlands and the rest of Western Europe, a consequence of the Mayfly’s general low tolerance for pollution.