Volunteer Seabirds at Sea

I was delighted to be able to take part in the fantastic Volunteer Seabirds at Sea (VSAS) training opportunity offered by the SOC and Joint Nature Conservation Committee (JNCC) that took place back in September 2021. I’ve always had an affinity for seabirds having spent part of my childhood on the Cowal peninsula in Argyll and Bute and attended the University of Aberdeen, where field trips to the Ythan Estuary, Troup Head, and Cromarty Bay meant I wasn’t short of opportunities to become familiar with our seabirds.

Right: On the approach to Islay during a sunny spell © Mark Lewis

However, my involvement with seabirds really began when I joined the SOC and the various opportunities that I’ve been afforded through it. With opportunities such as the SOC Young Birders’ Training Course on the Isle of May and involvement in the Clyde Branch Black-headed Gull Count, my interest in seabirds has been able to flourish into contribution to citizen science projects, including the VSAS programme.

The VSAS programme is a citizen science project run by the JNCC which forms part of the CalMac Ferries Marine Awareness Programme. VSAS volunteers use the established network of CalMac crossing routes to collect data on seabirds using the European Seabirds at Sea (ESAS) methods. This ensures that the data collected is standardised and is of good quality. The data provides essential information about seabird abundance and distribution and can be used to inform sustainable marine management, environmental impact assessments and academic research.

The VSAS mentor course consisted of three days of intensive training, with the first day spent indoors in the Village Hall in Tarbert. Here we learned about the VSAS programme, how it works, the methodology behind it and why the programme matters. It was an informative but also fun-packed day; we practised taking down records, made our own rangefinders using a ruler and a magic calculator, and were entertained with some role play on how not to conduct VSAS surveys. Finally, we formed two teams and challenged the other to a quiz of our own to see whether what we’d learned about the methods had stuck.

Above: Watching the clouds break above Islay and Jura © Mark Lewis

The survey method involves surveying a transect that runs parallel to the direction of the vessel. The transect consists of four bands: A (0-50m), B (50-100m), C (100-200m) and D (200-300m). There is also a fifth band, E, which includes observations beyond 300m. Band A is closest to the vessel and is the largest band that is visible. Although the bands increase in size, they seem smaller the further from the vessel they are. This is why we have a rangefinder to help place observations of seabirds on the water into each band. The survey method also involves scanning the transect with the naked eye, with binoculars used sparingly to confirm identifications. This is because the survey is focused on birds which are within 300m of the side of the vessel, and the further away the bird is, the more difficult it is to identify.

Above: The survey transect (A-D 300m, E >300m) © JNCC

However, the ESAS method takes into account that observations may be too short to allow identification down to species. For example, it’s difficult to distinguish between guillemots and Razorbills at sea, especially when they are far away or in flight. They also dive very early on if they see the ferry is about to cross their path, so you may only see them for a few seconds before they’re gone! So, if you’re not able to confirm an identification, or you’re not confident with it, you can record down to family. This is particularly handy for large gulls, for which juveniles and sub-adults are notoriously difficult to identify to species.

On the second day, we put our new knowledge to the test and braved the cold winds to start putting the methods into practice. Starting early to make the most of the day, we boarded the 7am ferry at Kennacraig to complete four two-hour crossings! Upon boarding, we got the equipment together (never forget your rangefinder!) and ready to go for the survey. While waiting for the ferry to get up to speed (~14 knots steaming), we had time to enjoy a CalMac breakfast (they do some nice hash browns). Then it was on with the waterproofs and out to the front of the ferry to start the survey.

Above: Exactly how to use your rangefinder © Mark Lewis

At first, it took some time for us to get used to recording our observations using the tablets. But as we got used to the layout and the information we needed to record, the faster we got at recording the data. This is just as well because we learned very quickly that you need to be fast! We learned after only a couple of crossings that surveying seabirds at sea can be highly changeable. There would be quiet periods when there were no birds in the transect, then suddenly, we’d be frantically trying to record a large mixed-species flock with birds diving and flying in all directions!

The changeable nature of seabird observations at sea is where knowing the essential information that needs to be recorded is paramount (species [or family], count, and transect band [if on water] or flight direction [if in flight]). There are also many factors to take into account when surveying at sea, including the weather, sea state, wave swell, sun direction and wind force etc., as all can impact your ability to detect birds on the water. For example, when the sea state is high, white horses from a distance can easily be mistaken for guillemots or Razorbills. Similarly, glare from the sun can mean you miss birds entirely.

By the third day of the course, we were like seasoned professionals, shouting out the essential information for each record and tapping away at the tablets with ease. During the course of the two days spent at sea, we practised the survey methods on eight crossings in total, each with a different survey partner. Having the opportunity to work with each of the other course participants was a great way to get used to carrying out the survey with different survey partners. We also had the opportunity to spend some time socialising in the evenings, which was a lovely way to get to know some fellow SOC members.

Above: A windswept bunch near the end of the course (Jura in the background) © Danni Thompson/CalMac passenger

Throughout the course, we surveyed large numbers of gulls, Kittiwakes, guillemots, Razorbills, Shags and Gannets. There were also some sightings of rarer species including Arctic Skua, Manx Shearwater, Arctic Tern, Red-throated and Great Northern Divers. On a couple of crossings, we caught glimpses of a storm petrel dancing on the waves, and came across a couple of pods of porpoises. We also had some unexpected sightings, including one of a Hen Harrier crossing the Sound of Jura while we were on our way out of Kennacraig and we were treated to a pair of White-tailed Eagles that were spotted sitting on a rock as we passed.  

Since completing the course, I have so far undertaken two surveys, both on the Ardrossan to Brodick (Arran) route. This crossing is fairly short, only one hour there and one hour back, but it’s a good one to start with. I carried out the first survey in November with Michal, another VSAS volunteer. It turned out that it was the first time surveying that route for both of us! Luckily, we had great weather, a calm sea state, no rain and not too much wind. For my second survey in January, I was joined by James, a fellow VSAS course participant. This survey was bitterly cold and not so sunny! It was also quiet in terms of bird activity, but no data is also good data. Still, we had a good time and it was good to get out in the fresh air.

Above: On the approach to a moody Arran in January © Emma Anderson

So far, each crossing I’ve surveyed has been different and has brought different challenges and surprises. Every one has been exciting as there’s always the possibility that you might record a species you haven’t seen on that route before, or you might come across a rare sighting. And if nothing all that exciting happens while you’re out on your survey, a day out with your fellow surveyor surrounded by beautiful views and fresh sea air is well worth it. I know I’m certainly looking forward to carrying out some surveys when I can on the more remote routes in the Hebrides.

Above: A wet and windy survey from Ardrossan to Arran (snow on the hills!) © Emma Anderson

If you’re interested in joining the VSAS programme, whether you are an experienced birder or a beginner, you can take part. The JNCC will be running further training courses this year, including one mentor training course and one surveyor training course in March. The Seabird Group have also just announced details of a new grant which may help towards the cost of training opportunities like the scheme described here. For more information visit the Seabird Group website here.

Finally, a big thank you to the SOC and JNCC for organising the course, and to the course trainers, Mark Lewis (SOC), Danni Thompson (JNCC), and Tim Dunn (JNCC), as well as my fellow course participants who all made the course such a wonderful experience.

Emma Anderson

"I have always recorded seabirds on ferry crossings, but the VSAS training is a great opportunity to record seabirds in a more structured way which maximises the value of the data. The training supported by SOC was a great opportunity to meet like-minded people and improve my seabird identification skills. I am due to carry out my first VSAS survey in late February and hope to carry out more during the summer".

Alister Clunas, fellow course participant

“On reflection the VSAS training course was a fantastic experience. The trainers Danni, Tim and Mark deserve a lot of credit for the friendly and supportive way that the course was conducted, while always being on hand to offer guidance and instruction when required. The camaraderie among the candidates was fantastic, and it was brilliant to spend time in the company of such friendly, like-minded people with a similar interest in nature. Email addresses were exchanged, and new friendships forged. The friendliness of the Calmac staff should also be mentioned, and they were always so courteous and appreciated the importance of the VSAS surveys. If you are interested in carrying out seabird surveys then I’d highly recommend the VSAS training course - spending a few days learning the skills of seabird surveying, surrounded by the spectacular scenery of Islay, Jura and the Kintyre peninsula, wining and dining in fantastic restaurants with great company – what’s not to like?”

Craig Gordon, fellow course participant

"The joint SOC/JNCC VSAS mentor training was an excellent experience and a fantastic opportunity to both learn and develop my survey skills, all whilst having the chance to chat and gain knowledge from others both leading and attending the course. My birding highlight of the 3 days was definitely watching a lone Storm-petrel pass just below the bow of the ferry making its way North over breaking white caps! Since the course I have taken part in one more VSAS crossing on the Arran route and I'm planning to take part in further surveys during the Spring and Summer".

Sam Hood, fellow course participant

"The VSAS training has been a fantastic opportunity that’s given my birding a new lease of life. Expert training in the classroom and in the field alongside a great mix of participants has helped me advance my seabird identification in ways I could never have imagined on my own. I’ve been able to take part in some of the regularly advertised surveys and looking forward to future ones gives me a new purpose and focus for developing my birding skills. I can’t wait to get back out there!"

Chris Wallbank, fellow course participant

"The VSAS course was an excellent experience learning with a group of like-minded people, how to survey seabirds at sea. The tutors were knowledgeable and approachable, allowing us the chance to ask lots of questions. I particularly found the class-based theoretical aspect, followed by ferry-based surveys beneficial in cementing the VSAS methodology. I have since been on a survey already and have signed up for a few more this season. If you’re thinking of taking part, don’t hesitate, it’s a brilliant course which will sharpen your bird ID skills and facilitate getting you out on the sea surveying seabirds and collecting vital data".

Shenaz Khimji, fellow course participant