Paul Thompson has been researching marine mammal behaviour and ecology for 20 years. He is currently Professor in the University of Aberdeen’s School of Biological Sciences and Director of the Lighthouse Field Station, Cromarty, which he set up in 1989.

I grew up on the north Kent coast, just outside Whitstable. We couldn’t actually see the sea from home, but it was just a two-minute walk and you were on the beach. A rather boring beach, looking back, but we spent a lot of time in, by and on the sea. The north Kent coast was a great spot for birds, particularly wintering waders and geese on the mudflats and fields. From the age of eleven or so I did lots of bird watching, and it was this interest in birds that led me to study biology at University.

Now, it’s difficult to divorce my strong passion for the sea from an equally strong passion for living in Scotland. The Moray Firth coast is a very special place, but I have to admit my favourite places are small islands. Perhaps the Moray Firth is a half way house between the Thames Estuary where I grew up, and those more rugged coasts of the western and northern isles. I’ve been lucky enough to visit some wonderful beaches in other parts of the world, but Scottish coastlines really take some beating; not just for their wildlife interest but as places to reflect, enjoy and relax. 

When I first moved to Scotland in 1982, I lived in a wonderfully remote area on the north coast of Islay. The following year I moved to Orkney, which at first seemed rather busy after Islay. On Orkney, you’re rarely more than a stone’s throw away from a farmhouse or a fence, and you don’t have the same extensive wild hills that you get on the west. Instead, you’ve really got to be on the water to get that wilderness feeling. Luckily, that’s exactly what my work involved. I had access to a boat and we spent much of our time out on the water. I also managed to see the whole of the coast of Orkney during several helicopter surveys which was quite a privilege.

And so to seals. While on Islay I’d been trying to get a post studying birds but I ended up working on marine mammals. At that time only two or three people had carried out UK- based PhDs in marine mammal ecology. Prior to that, anyone wanting to get into the field really had to go overseas. Things have certainly changed since then, as Cromarty alone has now produced fifteen PhD students, and each year Aberdeen, St Andrew’s and several other universities produce scores of graduates who’ve experienced research in this area. In contrast, when I applied for my PhD – to study harbour (common) seals – my main qualification was that I’d lived on an island and was used to living in remote areas!

Although a PhD student at Aberdeen, my project was largely based with the Sea Mammal Research Unit which later moved to the University of St Andrews. They had lots of experience of working with grey seals which remain ashore during the breeding season and, whilst they aren’t easy to handle, at least generally stay put. But when it came to harbour seals, much less was known about them and they were difficult to catch and handle; so some colleagues thought we wouldn’t be able to catch, tag and track them. It’s still not easy, but now people are routinely putting radios and data-loggers on these animals and following them around.

Most of my work has been applied research – in relation to management or conservation issues. Much of my PhD in Orkney involved working out how many harbour seals there were in that population. We’re still struggling to reliably count many marine species. Ultimately we want to see how the numbers of animals change over time and what’s causing those changes; but that’s difficult if you can’t count them effectively. Seals have the advantage over fish and dolphins as they do at least lie on the beach for much of their time. But we have to find out the best time to count them, for example when the number of seals ashore is most predictable. Then we need to work out how much of each seal’s time is spent ashore, so we can adjust counts to allow for those seals still in the water. That’s where the radio transmitters come in, as they can be used to work out whether each seal is resting on the beach or diving at sea. And the tags can also be used to find out where they were going when they were in the water.

More recently, people have used satellite tags, where the tag on the seal is detected by a satellite and you can sit at your computer and download the data via the internet. But “in the old days” it was a case of using a VHF radio tag – a bit like a CB radio. We used to wander around the coast with what looked like a television aerial, listening for seals.  In Orkney in the early 1980s a lot of people were very sensitive about radioactivity. I later heard rumours that I was suspected of prospecting for uranium whereas I was listening for missing seals! On the beach you lose the signal when a tagged seal is less than 10kms away, but if you get higher, up a hill or in a plane, you can hear them from much further. In Eynhallow Sound in Orkney we’d be able to watch tagged seals on the beach and hear the signal and then track them swimming out to sea. But then they’d go round a corner and the signal would get weaker and weaker before disappearing into this ‘black hole’. They may have only been going a mile or so around the corner under a cliff, or twenty miles offshore, but at that stage we simply didn’t know.

In 1987 the government contracted the University of Aberdeen to do a three-year study on harbour seals in the Moray Firth. This was largely driven by the age-old controversy between seals and salmon fishermen, but also aimed to provide background information on number of seals, where they were feeding and what they were eating. It was then, when I moved down to the Moray Firth from Orkney, that our work focused more on seals’ feeding habits. One of the exciting things about working in the Moray Firth is that the seals that rest on the sandbanks in the inner firths are never far from land when they head off to sea to feed. And they can’t easily disappear around a headland as they’d done in Orkney. This meant that 99% of the time, from somewhere on a hill around the Moray Firth, you could find your animals. So this was the first time that we started to get a picture of where harbour seals were going to feed.

As to the conclusion of that three-year study, it’s probably best summed up as “things are a lot more complicated than most people think”. When we know very little, it’s easy to have preconceived ideas about what’s happening and how simple the system is. And then, as you gradually start to understand the animals and the ecosystem, life gets a lot more complex. The problem with applied science questions is that, so often, you tend not to produce nice clear precise answers. There’s huge uncertainty over many issues. Even if we could show what seals were eating last year, that doesn’t mean we can predict with certainty what will happen next year. Especially as the fish stocks could be very different from year to year. Our work showed that seals eat many different fish and other species like squid and octopus. They certainly don’t spend all their time eating salmon; neither do they spend all their time hanging around the mouths of the salmon rivers. They do come into the inner firths to rest and have their pups but they’re generally going much further out to sea to feed.

In the last year or so a new Moray Firth Seal Management Plan has been developed, with all the Salmon District Fishery Boards working together. This has drastically reduced the number of seals being shot in the area, and the plan focuses any control in those areas where seals are most likely to have an impact – particularly when they start moving into the rivers or feeding around river mouths.  There’s now a growing understanding of those interactions, but it probably takes a generation to change the culture underlying this kind of management problem. But now, most salmon fishery managers realise that improving the breeding habitat in rivers is probably a more effective way of improving salmon catches than shooting half the seals using the local haul-out site.

Dolphins have been seen in the Moray Firth since the late 1800’s, but they were really beginning to capture the public’s imagination at the time we arrived here in 1987. Conventional wisdom amongst the scientific community was that cetaceans were too unpredictable to do any useful research around the UK, so most work on cetacean ecology was either done overseas or based on dead animals. But when out in the boat working with the seals we often used to see the dolphins, especially around the mouth of the Cromarty Firth.

Bottlenose dolphins off Cromarty © EcoVentures (Craig Morris)

By 1989 we’d realised there was potential to do more work with the dolphins. It was known from organisations such as the Mammal Society’s Cetacean Group that the Moray Firth was one of a couple of places in the UK where you regularly saw bottlenose dolphins. At that time it was thought that there were maybe 15 or 20 animals – in other words the number of dolphins that people saw on any one occasion. So the first thing we did that summer was to get a bunch of people together, standing on different bits of the coast on the same day. We were lucky. The weather was fine, and by comparing the notes that everybody took from different places, it was clear that there were at least 60 – 65 dolphins in the area.  At about the same time we started going out in the boat to see if we could photograph animals and recognise different individuals by their dorsal fin (photo-ID).

Lots of classic studies have highlighted the value of basing ecological studies on known individuals rather than anonymous animals within a population. In some cases animals such as birds can be caught and marked. In the case of dolphins we can recognise different individuals from their natural marks. Recently, these long term studies of individuals have been especially useful to help understand the effects of climate change. As well as the dolphin and seal projects which we started in the Moray Firth, the Field Station has inherited a long term study of fulmars in Orkney. Aberdeen University started this study in 1950, so we’ve over fifty years of data to explore how changes in climate and fisheries affect these seabird populations. 

With over fifteen years of data on dolphins in the firth, we are now also seeing evidence of changes, for example in social behaviour and movements, which seem to be related to climate variation. But working out what’s really causing these changes is difficult. We assume they’re being driven by changes in food, and climate variation is affecting them through changes in plankton and fish stocks. But in the case of the fulmars, we don’t know where they feed. Compared with many other species, we know a lot about seabird population change but much of this is based on studies at their breeding colonies – not when they’re at sea. Similarly, much of our understanding relates to the summer breeding season and less is known about what they’re up to during the rest of the year.

When finding out where animals go to feed, seals certainly have the advantage. They can carry relatively large tags and have hair that we can glue the tags to. Similar work on dolphins in the firth is impossible as you can’t attach tags to them and, for birds, the tags have to be really tiny. Having said that, the technology is getting there, and seabird biologists in Canada have now put satellite tags on fulmars in the Arctic, showing that birds flew right across the Atlantic during the winter. So our birds in Scotland, and even the birds breeding around the Cromarty Firth, could be wintering around Greenland, Iceland or down in the southern North Sea. Hopefully in the next few years we’ll have a much better picture of this.

As with so many jobs, as time goes on I spend more and more time behind a computer. It’s still great to get out there with the animals, you don’t want to lose that, but even at the computer I can still get excited about the data. I do miss the hands-on work that we used to do with the seals – the weighing, measuring and assessing health - and then releasing the tagged animals we’d track over the following weeks. That work ended in 1995, so it’s been fun to be doing more work like this with the seabirds in recent years.

Like our annual estimates of the number of dolphins in the firth, each year we count the number of fulmars nesting on Eynhallow. To count the birds we just go up for a weekend in late May and I’ve got the answer. But to work out the number of dolphins, you need three people and a boat, making around twenty photo-ID surveys over the summer, and then one person spending most of the winter analysing those photographs. Then, all being well, after much number crunching you’ve got the number; which is why it can be difficult to persuade many ecologists that it’s worth doing research on those animals!

Over the years my work has given me many memorable experiences. Last summer I was able to do surveys on the west coast, combining research and family holiday. It was my wife Sarah’s birthday, and we were taking the boat across the Minch after a night on Eigg. We’d been round the coast of Rum, and at the west end of Canna a basking shark suddenly breached in front of us. It flew right out of the water, just like those Great White Sharks on ‘Planet Earth’! We got half way across the Minch when all of a sudden we were surrounded by about fifty common dolphins. I’d never seen a large group of common dolphins before and they were absolutely frantic. They seem so tiny compared with the bottlenose dolphins here, especially the calves which looked about the size of rabbits. They’d rush around together and then break off into little groups, speeding off about a quarter of a mile away before suddenly returning to the boat.

Another memorable moment with dolphins in the Moray Firth occurred soon after we arrived. We were out trying to catch seals. It was at the time that we were starting to realise that dolphins were here quite regularly. We were just heading out between the Sutors when these two animals – I guess they were bow-riding the boat – were coming up either side of the Zodiac. Surfacing so close to the boat they were splashing us. But there have been many days like that when the animals have been working round the boat, so close that you can see what’s happening under water.

There have also been some great moments watching dolphins from Chanonry Point or unexpectedly spotting a group when you’re on the shore at Eathie. Chanonry is now so well known for dolphins that it can be incredibly busy during the summer  – you can be down there with 100 or even 150 other people. I‘ve been pretty privileged, going to remote places and being able to go out with our own boat to get a remoter wildlife experience. I suppose the challenge is to try to find ways of allowing more people to have that valuable experience with the sea and wildlife without it starting to spoil the experience or damage the environment. That’s one of the issues being addressed with the new Scottish Marine Wildlife Watching Code, and the Dolphin Space Programme. 

Managing wildlife watching is just one of the challenges facing us in the Moray Firth. Across the North Sea we’re seeing major changes in plankton communities and fish populations and the implications for marine mammals and seabirds are far from clear. What’s causing this – is it climate change, is it fishing pressure or pollution? And even if we knew the answer to that question, what opportunities are there for restoring what used to be such rich waters around our coasts? I’d like to think that we can leave the Moray Firth looking more like the west of Scotland than the Thames estuary, but the future is far from certain and it’s largely down to those of us who live around its shores to shape its fate.

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