Friday 7 October 2011

The Voyages of King John

The first time it happened I was in my local pub in Wiltshire when I received a call from a naturalist friend of mine in West Wales who had been out on a dolphin watching trip in the Irish Sea. “You’ll never guess who I saw today?” was the message and I instantly knew it was him.

Fast forward a few months to Scotland and to the emailed photo I received from a colleague from the Whale and Dolphin Conservation Society conducting a land-based cetacean survey of the Hebrides. And there he was again. John Coe - an adult male orca, a legend of the west coast and one of the most distinctive animals in our waters.

For the past three years I had been receiving sighting reports of John Coe off the Pembrokeshire coastline in late May and June, always just passing through and always heading north. My colleagues at the Irish Whale and Dolphin Group were also starting to report sightings of him off the west coast of Ireland at different times of the year but it’s Scotland where the story of John Coe (and co!) really begins.

John Coe was originally named in the early 1990’s by the skipper of a local sailboat on a Sea Watch survey around the Western Isles and takes his name from a character in a poem. He had been sighted first in 1980 and was an adult then, making him at least 40 years old. Whale watching off the west coast can be hugely rewarding but also requires patience – orcas, for example, can travel up to 100km in one day. But anyone fortunate enough to see a pod of orcas in the wild can’t fail to be impressed by the incredible beauty of these iconic animals as they effortlessly break the surface, their dorsal fins rising and falling in poetic synchrony. I still can’t think of any other animal that has such a powerful affect on the human spirit just by breathing.

Individual orcas can be recognized by photo-identification as all have unique markings composed of nicks, scars and scratches on their dorsal fins and on the grey saddle patch found just behind the fin. John Coe has a huge V-shaped notch out of the trailing edge of his dorsal fin making him unmistakable. Being able to identify individual animals allows researchers to gain important information on group structure, social associations and movement patterns. Indeed, the best studied orca population in the world today is the resident salmon-eating group found around Vancouver Island in the Pacific Northwest which researchers have been cataloguing since the early 1970’s. They know every single individual in that population (240 ‘northern residents’ and 87 ‘southern residents’) and have followed some members since the day they were born.

Orca studies in the North East Atlantic are quickly catching up. John Coe is part of a group referred to as the ‘west coast community’ which currently comprises just nine individuals - four males and five females, although some observers have recorded occasional sightings of 14-15 animals. All the animals in this community are often seen with each other but some are more regularly sighted together than others. John Coe, for example, is frequently sighted travelling with just one other female, likely to be his mother.

Dr Andy Foote and The Hebridean Whale and Dolphin Trust studying this small group believe this could be an isolated community since it shows no association with the orca groups found around the north east of Scotland, Shetland and Orkney. This is backed up by recent findings that the population has different physical characteristics suggesting a separate ancestry.

It is still not known what this group feeds on but researchers believe their diet includes other cetaceans. There has been at least one confirmed predation event on a harbour porpoise and others report witnessing dolphins swimming extremely close to shore and minke whales abruptly turning and fleeing whenever this group is passing through.

Meanwhile, the Shetland and Orkney orcas - mainly summer visitors to the area – are known to coincide their visits with the seal pupping season. They are believed to be a part of a wider North East Atlantic population and the individuals identified feeding on seal pups here are associated with the Icelandic herring-eating groups. Further north, there appear to be healthy populations of orcas around northern Norway which feed on herring and also around the Faroe Islands and southern Norway which feed on North Sea mackerel. These populations can range over vast distances. In January this year, fishermen report seeing up to a hundred orcas feeding on mackerel off County Donegal having travelled down the ‘outside’ of the Hebrides following the fishing fleet.

Around the rest of the UK, sightings are less common. In the southern North Sea and the English Channel, sightings are rare though there are records of orcas stranding on the Kent coast. In June 2010 a young, malnourished female - nicknamed Morgan - and believed to belong to the Norwegian population, was rescued from the south eastern part of the North Sea off the Netherlands and is currently undergoing rehabilitation in a Dutch dolphinarium while authorities and conservation bodies debate her future.

The future for John Coe and the last ‘resident’ pod of the British Isles remains uncertain. Not a single calf has been seen in this group for nearly 20 years making their conservation status critical. In 2005, a dead newborn calf was found on a beach on South Uist which had similar features to the west coast community. As top predators in the marine food chain, pollution may be to blame. Female orcas pass some of their pollution burden onto their calves when they nurse them and this is thought be the main reason why infant mortality is so high, especially for the first born. These studies continue to give us a glimpse into orca society and the environmental and man made threats they face.

I’ve spent hundreds of hours at sea and walking the headlands of these majestic isles and I’ve been fortunate to see orcas all over the world but as for me and the mighty John Coe, we’ve yet to meet.

There is still much to learn if this small, isolated population is to survive on the Scottish west coast and to ensure John Coe does not become the last King of Scotland.