Survey Reports

2018-09-10 - Oban–Castlebay

Survey details

Survey route: Oban–Castlebay

Company: Caledonian MacBrayne

Sea region: Minches & Western Scotland

Survey start date: 2018-09-10

Number of nights: 1

^ A library image of a common dolphin

Considering 40+ mile an hour winds and large swells were forecast at various periods during the two days of this survey it was touch and go whether conditions would be favourable enough to actually survey.  But not to be beaten the team boarded MV Isle of Lewis determined to give it our best shot. 

We soon accessed the bridge and had relatively easy conditions through the sheltered Sound of Mull.  As we left the sound we were greeted by a large, over 2 meter swell but despite the roll, the wind wasn’t too bad and averaged a sea state 3-4 for most of the crossing. This we could cope with, and south east of Hawes bank we briefly picked up 2 common dolphins.  The bank itself was relatively quiet but we recorded another 5 common dolphins on the other side. Half an hour later a group of 4 bottlenose dolphins, travelling slowly, passed us a little way off the ship. 

Despite the rain on the walk from the harbour to the hostel in Castlebay we enjoyed the evening in their friendly lounge  beside a raging fire with the wild Hebridean wind increasing outside.

The worst of the weather passed in the night and we then had another window before more high winds were predicted for the afternoon. The swell had dropped somewhat but the wind had picked up and risen to 5.  The  mammals we found during the crossing were 17 common dolphins spread out across Hawes Bank entertaining us with a lot of breaching. There was certainly passerine migration taking place as hundreds of small birds passed us including grey wagtails and pipits. Interestingly the bonxies that have been in the Minch in huge numbers over the past couple of weeks were not in evidence, we only saw one, and we also picked up a very late leaving Arctic tern.

The survey was certainly a lesson in how perseverance can produce results and with a little bit of luck we were able to dodge the very worst of the weather. Two team members were new to surveying and it actually turned out to be an excellent introduction for them providing them with a range of conditions and scenarios, which they both steadfastly embraced.

An extra special thank you to the bridge crew who accommodated us under difficult conditions, with their own complications, and allowed us to work unhindered.

Marine Mammals:

Common dolphin 24

Bottlenose dolphin 4

Birds

Gannet, manx shearwater, kittiwake, great black-backed gull, herring gull, storm petrel, fulmar, shag, common gull, guillemot, razorbill, Arctic tern, great skua, pipit sp. and grey wagtail.

Survey team members

Andy Gilbert, Alastair MacDonald, Iain Pringle, Sharon Clough