Environment Sub Committee AGM Report February 2024

The sub-committee, through the stalwart efforts of Malcolm Thomson and a small army of volunteers, have put in a very busy year trying to fulfil the ever expanding moral responsibilities of any local organisation charged with trying to protect the fishery for future generations.  In the absence of a local Rivers Board or similar entity, as enjoyed by regions further south, the OTFA are left to sample fish populations and monitor habitat. We need this in order to have any data for evidence based discussion with planners and developers.
Further to that, our own member’s emerging observations regarding climate change and the way in which it can aggravate already existing environmental challenges, means that we have a rapidly expanding remit of things that we need to start recording and looking at. So going forward, we are looking at a scenario where we will need even more volunteer effort.
The following issues have been our main concerns this last year.

Harray Nutrient Data: The sub-committee are trying to build up a picture of Harray’s various historic water qualities and have received data from 2012 – 2023 from SEPA.  Analysis is currently ongoing.

Water Temperature Recording:  We are looking for any historic water temperature records for the lochs.  We wondered about the OTFA deploying its own temp recorders, but we don’t think this will happen for the time being.  We are currently researching further options.
Local Biodiversity Action Plan (LBAP):  This process currently seems to be stalled at OIC after a series of cancelled and postponed meetings.  

Environmental Management Plans (EMP’s):  Fish farm companies still developing EMPs and we are in talks with them to see how this will develop.  You will recall that EMPs were introduced as planning conditions at some recently approved fish farm developments and that they were to be in place before the development occurred.  So they are well behind with this and the OIC is not showing any apparent concern.

Sweep netting in 2023: The sweep netting results have been detailed in a separate report that has been made publicly available on the OTFA website.  The results were clearly concerning, and give an indication of the pressure that our sea trout have been under this last while, particularly in Scapa Flow.  Lice levels on salmon farms remain high and this appears to be the new normal with the two operators apparently struggling to get levels down to an acceptable level.  The committee is currently considering what level of sweep netting to undertake in 2024. 

Fyke netting: This project (run by Malcolm through SULA Diving) saw the deployment of fyke nets on 16 occasions in 2024.  The survey sites included the Bay of Ireland, The Bush, Houton and Waulkmill.  Deployments were limited to daylight hours due to the SPA status of Scapa Flow.  The project demonstrated that fyke nets set in this way are not effective at catching sea trout, as only two were caught over the whole project. This keeps the emphasis on sweep netting as the best available method for sea trout sampling.

Netherbrough Burn Electrofishing Survey 2023: This survey looked at numbers of juvenile trout at five sites along the length of the Netherbrough Burn.  Full details have been reported on the OTFA website.  The survey found healthy numbers of 0+ trout at all five sites, indicative of good spawning activity over the winter of 2022/23.  At the most upstream site (Millhouse on the Lyde Road) a density of 144.4 0+ trout per 100m2 was recorded, which was comparable to the results of previous OTFA surveys carried out between 2004 and 2008.  These results were encouraging and underline the value of the Netherbrough Burn as a spawning habitat serving the Loch of Harray. 

Arctic Char: Samples of recently caught Heldale fish are currently with UHI Inverness for DNA analysis. We are hoping to establish whether these char are original native fish or (more likely) from an invasive stocking event more recently.

Trout in the Classroom: This valuable project will run at Papdale Primary this year, starting on Monday 5th February.  A total of three classes will be involved (over 70 children) and we intend to run two tanks of eggs, each housed in a fridge provided by the OTFA. The fish are reported to be hatching this week and the use of the fridges has been working out well.

The chair would like to thank Malcolm Thomson in particular for his tireless efforts and time this year, organising these ongoing projects and leading their execution. We would also like to give our thanks to the loyal group of volunteers who have made the sweep netting project achievable as well as Orkney Hyperbaric Trust, SULA Diving and Andy Cuthbertson at Scapa Flow Charters for the use of time and equipment.

Colin Kirkpatrick
OTFA Environment Sub Comm. Chair