Surveying both land and water on Ronay Island
As already mentioned in this blog series, 2025 has seen a comprehensive baselining exercise undertaken on Ronay Island.
So why baseline and what is it?
Before we start any works to ecologically enhance the island, we need to know what is there, is there anything that our actions could impact, and to provide a datum point so that we can monitor changes in the future.
The first challenge was coming up with a mechanism that allowed a representative snapshot in time to be assessed, on a remote, uninhabited island, with no paths or tracks. Surveying a 650 plus hectare island for all the species and habitats is a very time-consuming and complicated exercise, so rather than look for everything we have worked with rePLANET to carry out the ‘Basket of Metrics’ approach as outlined by the global recognised Operation Wallacea approach.
Our baselining approach
The Basket of Metrics approach sees five different areas assessed, to provide a numerical index of the ecological value of island, to build up a picture of what is there and the level of abundance. To reduce time on site and make the project more cost effective, rePLANET partnered with Mozaic Earth, to use their App based technology to gather the data required, to be assessed remotely.
The surveys have looked at the under lying habitats, the birds breeding on the island, the pollinating insects, the ground beetles and plants.
The birds were assessed using recording boxes, located in 6 locations across the island, recording constantly for just over a month, from late April, until early June. The recorders were supplied by Carbon Rewild. It is important to stress, that these boxes do not and will not pick every species up, but by spreading them across the island, considering the different habitats, we get a very accurate representation of the breeding birds and their abundance. By cross referencing the results from Carbon Rewild, with ad hoc records from time on the island and local records, we are very pleased with the accuracy of the results.
The pollinating insects, ground beetles and plants were assessed twice, once in late May and once in late July. The two surveys were carried out in the same locations, using the same technique each time, to ensure seasonal differences in species were picked up.
Ground beetles were assessed using pitfall traps. Pollinators assessed using pan traps, and plants assessed by taking photographic records of quadrats.
The habitat surveys were completed by the collection of photograph sets from pre-selected habitat assessment points. Initially 12 habitat zones were identified, with at least 12 data collection points in each zone. After the first visit, a further 6 zones were added to take into account additional habitats identified, or areas where further detail was thought to be required. This data was all collected through the app, with the points GPS located, to allow repeat visits in future years.
A challenging process
Very few people have walked on Ronay in recent times, and one of the biggest challenges faced was navigating around the island, to get to the pre-selected survey locations. With no paths or tracks, rough ground, peat bogs and steep slopes to overcome, planning days on the ground, and being realistic about what could be achieved each day was key. Added to this terrain was the wonders of the summer weather in the Outer Hebrides, stunning sunny weather was shared equally with torrential rain and summer storms, with wind gusts that blew you over. The terrain and weather were additional reasons for the adoption of tech solutions to speed the process on the ground up.
The following stats show the scale of the work undertaken…
A total of 36 staff days spent collecting data between Easter and the beginning of August
6 bird recorders located
18 habitat assessment areas, with 12 collection points in each area, with 5 photographs taken at each location.
20 x 1ha plant survey areas, with 15 data collection points in each area, with 5 photographs at each location, completed twice.
60 ground beetle traps set up, twice
12 pollination traps set , twice.
A minimum of 4,224 separate pieces of data collected
Approximately 800,000 steps walked
At least 4 bogs fallen into
Uncountable number of ticks removed, and midge bites soothed!!
Surveying Ronay’s many lochs
As water is such an important element on the island, and the Basket of Metrics approach doesn’t really take the water into account, thought was given as to how the water bodies could be assessed. Following conversations with professional ecologists, it was decided to carry out eDNA assessments of the 12 main freshwater water-bodies on the island. This was completed in July, with 32 separate samples collected. Each sample covered approximately 200m of shoreline. With 1.5ltrs of water collected for each sample point, and then syringed through an exceptional fine filter, the DNA of all the species within a waterbody is collected. This process does not assess abundance, but it will give a very comprehensive assessment of what is using the water bodies. We worked with Trace Biomonitoring, who supplied the kits and processed the samples.
A big thank you
Throughout 2025, an excellent understanding of what is using the island, and the condition of habitats has been built. This would not have been possible without a vast array of people. We would like to particularly thank the following people and companies for making this happen.
From rePLANET, thanks go to Max Bodmer, Indy Stephenson, Hannah Flintham and Dearbhla Holohan.
From Mozaic Earth, thanks go to Sylvain Vaquer and Johanna McQuade.
From Trace Biomonitoring, who supplied the eDNA service, thanks to Lewis Campbell.
None of this would have been possible without the support and assistance of the local community and particular Nye and Nick from Lady Anne Wildlife Cruises for the local wildlife insights and David Cooper for transporting the surveys to and from the island and ensuring the house was ready to use.
We look forward to sharing the complete results of our comprehensive surveys the in the coming weeks.
