Back in June, I collected a sample from the edge of Lago di Maggiore in Italy and performed an impromptu analysis to see if the outcome, based on my experience of British lakes, was in any way comparable with that of my Italian colleagues (see post of 17 June 2013). This is necessary if the EU’s environmental legislation is to provide a level playing field for all Member States and has occupied much of my professional life over the past eight years or so. Standing beside the Atma River, I decided to conduct a similar experiment, once again scraping some of the slippery film from the submerged rocks into a small bottle that I could slip past airport security in my hand luggage.
A chain of three cells of Tabellaria flocculosa from the Atma River in Norway, July 2013. The scale bar is 10 micrometres (1/100th of a millimetre) long.
The most abundant diatom in the sample, by far, was Tabellaria flocculosa, comprising well over 90% of all the diatoms that I saw. This forms long chains, each cell attached to the next by a pad of mucilage at one corner, which tangle in and around the other algae (in this case, mostly green alga such as Mougeotia). There were a few diatoms that I could not identify in this sample, because of the ad hoc method of analysis, but there were enough that were identifiable for me to be able to run the results through the calculations which we use in the UK to evaluate the status of rivers.
Had I performed this analysis on a UK river, I would have concluded that it was at “high status” (i.e. very close to its natural state), exhibiting no signs of enrichment by nutrients or of acidification. The good news is that this is what Susi concludes, based on her own analyses, which use the algae other than diatoms. So this informal exercise gives me double confidence: that standards in Norway and the UK are similar, and that we can reach the same conclusions using two different groups of algae.
The most surprising aspect, for me, is that I still had a good mobile signal whilst sampling this site. I usually associate “high status” with remote locations where the mobile signal is non-existent.