This wasn’t some secret or lurid hobby that I was developing my skills in, but rather the latest technique for assessing barriers to fish passage. SNIFFER stands for the Scotland and Northern Ireland Forum For Environmental Research and they have developed this tool to allow river managers and professionals to assess potential barriers to fish migration.

The three day course in Stirling taught us how to assess weirs, dams, culverts, waterfalls etc in relation to fish passage and to determine a score that could quantify the problem.

Assessing the porosity of a fish pass. This one had issues for some migrating species but not all.

Of course up to now we have relied on experience, local knowledge, electrofishing etc, but the difference with the SNIFFER method is it allows us to daw conclusions and prioritise action for  barriers based on measured flows, depths, heights etc. It can even be used to score the effectiveness of fish passes at differing flows and for different species.

SEPA now require SNIFFER assessments to support applications for Restoration Funding for barrier removal or alteration. Ideally I’d like to establish a program of barrier assessment across our River catchments to allow us to continue with the removal/mitigation work that we have been undertaking over the last few years. We will need to fund a flow velocity meter to allow us to do  this (approx £2000), but I’m sure before long we will have this in hand. Each survey requires 3 people so it is labour intensive and anyone with time on their hands and willing to assist should let me know.

A tributary of the Earn in Perthshire where we used the SNIFFER tool to quantify the scale of the problems at this site.

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