Survey Summary: HWDT 11

The fantastic citizen science team and crew of HWDT 11

Our citizen scientists and crew rendezvoused in Ullapool on the 31st August for the start of HWDT 11.  After the meet and greet, the team headed to Tesco’s for some last minute supplies (consisting of whisky and wine!), before Silurian spend the night on the mooring. As we left the pontoon, a troop of pipers headed down the main street to send us on our way!

Rendezvous in Ullapool allows for the exploration of some of the more northern reaches of our study area

During the survey we covered 265 nautical miles, spending 46 hours on effort looking for cetaceans, with a total of 1.5 hours logged “with whales” (or for this trip with dolphins!). Despite the wild, wet and windy weather, the team did an excellent job of surveying and spirits were kept high thanks to Simon’s marvellous soups and an endless supply of biscuits, tea and coffee. We spent the evenings exploring a few of the islands, or playing games and drinking whisky, with the best saved until last….plankton party in the Summer Isles! We stopped at some picturesque anchorages along the way including the absolutely stunning Loch Mharabhing, in the mouth of Loch Erisort.

The track lines surveyed and anchorages made during HWDT 11

Despite the gales and horizontal rain, we had 63 sightings of marine mammals: counting a total of 181 individual animals of 5 different species. Harbour porpoises were the most frequently encountered species, accounting for 29 sightings, totalling 47 individuals. We had two brilliant encounters with Risso’s dolphins off Tiumpan Head (Isle of Lewis Lewis), as well as a fantastic sighting of common dolphins as we headed back into Ullapool on the final day. A great end to a great survey!

Risso's dolphins seen off Tiumpan Head

We gathered valuable acoustic recordings, with the hydrophone deployed for 36.5 hours during survey. During this time, we heard and recorded snapping shrimp, lots of dolphin whistles, remote boats acoustic deterrent devices (ADDs).

Common dolphins are a very vocal species and can be heard through the hydrophone

Alongside marine mega-fauna sightings, the team  counted an amazing 2,598 birds. Kittiwakes were the most frequently seen species, followed by guillemots and then gannets.  We also saw great skuas chasing kittiwakes and 61 storm petrels (also known as snow patrols – to Maggie at least!).

A total of 549 creels were recorded, alongside 4 pieces of rubbish.

Thanks so much to Alex, Ceinwyn, Ciaran, DeAnn, James and Maggie who joined us on board and contributed to our research. We couldn’t do it without you!

Thanks also to Scottish Natural Heritage who help fund the data collection programme aboard Silurian.

Matt Clements, HWDT Silurian Support Volunteer

One of the many beautiful anchorages made during HWDT 11