July 2019

VSAS Survey report: Kennacraig to Islay, July 13th 2019

Volunteer Seabirds At Sea (VSAS) surveys were carried out from the forward viewing platform of the Kennacraig to Islay ferry on scheduled return crossings on 13^th July 2019. Data were collected to European Seabirds At Sea (ESAS) standard, by trained volunteers, using the JNCC VSAS app to digitally record data in real time.  

Environmental conditions were suitable for surveying, with visibility recorded as good to excellent throughout. Both Beaufort wind force and seastate ranged between two and three, and swell heights were generally below one metre.

A total of 93 observations were made of 9 species of seabirds (and a single 'species group' where identification could not be made to species level) during the dedicated survey effort. One species of marine mammals was observed. Numbers of observations and total numbers of birds and mammals recorded are presented below in Table 1.

Distribution maps

Figures 1 - 6 show the distributions of all seabird and marine mammal species recorded during the survey.

Figure 1. Observations of gannet, Kennacraig - Islay, July 13th 2019.

Figure 2. Observations of Manx shearwater, Kennacraig - Islay, July 13^th  2019.

Figure 3. Observations of other seabirds, Kennacraig - Islay, July 13^th  2019.

Figure 4. Observations of guillemot and GU/RA, Kennacraig - Islay , July 13^th  2019.

Figure 5. Observations of all gulls, Kennacraig - Islay , July 13^th  2019.

Figure 6. Observations of marine mammals, Kennacraig - Islay , July 13^th  2019.

Table 1. Numbers of observations and totals recorded per species

Species accounts

See figures 1 - 6 for maps of observations

Gannet(Morus bassanus)

In total, 40 birds were recorded over 27 observations. Many were seen mid-channel, but as with other surveys, there were also high densities noted in western West Loch Tarbert.

Manx shearwater (Puffinus puffinus)

13 groups were observed, comprising 31 individuals. All were recorded from areas of more open water.

Shag(Phalacrocorax aristotelis)

Two records of three birds, with both observations coming from waters north of Gigha.

Black-throated diver (Gavia arctica)

An interesting record of two birds together at the western end of West Loch Tarbert. This is the least frequently recorded of the three regular diver species, but this location fits in very nicely with other records from training trips.

Kittiwake(Rissa tridactyla)

Just three records of four individuals. Two of the observations came from the same area that Manx shearwater were aggregating in.

Common gull(Larus canus)

Just one noted, in the Sound of Jura.

Herring gull (Larus argentatus)

Five records of six individuals, with an interesting cluster of records from north of Gigha. Other observations were from West Loch Tarbert and the Sound of Jura.

Guillemot(Uria aalge)

The most numerous species recorded, with 34 observations of 54 individuals. They were observed exclusively in areas of open water, with most records mid-channel.

Razorbill(Alca torda)

Just two records of two individuals, with both birds noted from an area that also hosted good numbers of guillemot.

Harbour porpoise(Phocoena phocoena)

A single observation of two animals, from the area north of Gigha.

Acknowledgements

Thanks to the volunteers who gave up their time to take part in this survey - we hope this report serves as a useful reminder of your time on board! We would also like to thank the Captain and crew of the Islay ferry for welcoming the survey team on board, and Klare Chamberlain and Ruth Rice at CalMac who helped with access and other arrangements. Finally, thanks to Simon Pinder and Rob Petley-Jones at MARINElife for coordinating volunteer effort.