Friday, 15 April 2016

Your Guide to Orca in UK Waters

by Suzie Hall 

Orca sightings in the Northern Hemisphere are often associated with the shores of Iceland, Norway, the USA or Canada. But did you know that the UK has its own resident population of orca? Furthermore, the north of Scotland is also visited by other North Atlantic populations throughout the course of the year. So grab your binoculars and head to the British coast; this short blog will take you through the best locations and times of year to spot the majestic orca in UK waters.

West Coast Community Orca

The UK has its own small, resident population known as the West Coast Community (WCC), consisting of only eight or nine individuals. Although rare to find, the WCC can be spotted year-round in the Hebrides, along the West coast of Scotland. They have also been seen off the North West coast of Ireland, and some individuals have even been seen as far south as Pembrokeshire, South Wales in the summer, typically around June and July.

Photo: © Orca Aware
This orca population is believed to be the North Atlantic Type 2 ecotype. Although relatively little is known about the WCC’s feeding habits, their ecotype would suggest they feed primarily on other marine mammals. They have been seen hunting dolphins and porpoises, and it is possible they feed on other whales too. These North Atlantic type 2 orca are generally larger than their Type 1 counterparts. Studies have also shown that they have larger and sharper teeth than the Type 1’s, which makes them more specialised for hunting larger mammals.

Scientists at the Hebridean Whale and Dolphin Trust in Tobermory, Scotland have been gathering data on the WCC since 1994, and have recently made an interesting discovery. In the 1970s, a lone orca, dubbed Dopey Dick, swam up the River Foyle in Northern Ireland and it has just been identified that he is in fact a well-known member of the WCC, known as Comet.

The WCC also made the headlines earlier this year when a female, known as Lulu, was found dead on the Isle of Tiree in Scotland. The early necropsy released by the Scottish Marine Animal Strandings Scheme reported that there were deep lesions all over her body and that she had swallowed large amounts of sea water. They report that the most likely cause of death was entanglement in abandoned fishing gear, which subsequently led to her drowning.

Probably the most recognised member of the WCC is a male known as John Coe. He has been sighted by various organisations and members of the public since 1980 and is easily recognisable by the large notch towards the base of his dorsal fin. He is one of the individuals who has been sighted off the Irish and Pembrokeshire coasts, often accompanied by females. He hit the headlines in January 2015 when he was photographed with a large chunk missing from his tail fluke, believed to have been caused by a shark attack!

Sadly, the WCC are in danger of becoming extinct. No new calves have been seen since studies began and their dwindling population is already of a tiny size. In my next blog, I’ll be exploring how chemical pollutants found in the marine environment are likely impacting the WCC, in line with the latest scientific findings.

Photo: © Orca Aware
Visiting Orca 

During the summer months, the UK is visited by other North Atlantic Type 2 orca, as well as an entirely different ecotype, the Type 1 North Atlantics. Both visiting groups of orca are frequently sighted around the Shetland and Orkney Islands, as well as from the Scottish mainland, off the coast of Caithness.

Type 2 North Atlantic orca are actually more closely related to the Type A Antarctic ecotype. Type 2 orca, including the WCC, are larger than Type 1's and there are also differences in the orientation of their eye patches

Where Type 2 mammal-eating orca are ‘specialist feeders’, the Type 1 orca are considered to be ‘generalist’, primarily predating on fish species (such herring and mackerel), although they have also been known to feed on seals. This difference in dietary preference is the cause of severe tooth-wear in the Type 1 fish-eating orca, which results from friction between fish scales and an orca’s teeth when the orca ‘sucks up’ the fish.

At least seven of the Type 1 individuals sighted in Scottish waters have been identified as members of the Icelandic orca population. Although the Icelandic orca visiting UK shores primarily feed on herring, it is thought that they make their journey to the UK to coincide with the local seal-pupping season, which takes place from April to July.

How You Can Get Involved

Our knowledge of the WCC and the visiting groups of orca is increasing. However, there is still much that we have yet to learn about them.

Photo: © Orca Aware
Since 2012, a dedicated team of enthusiasts have been meeting at the northernmost tip of Scotland each May to participate in an Orca Watch week. The week, coordinated by the Sea Watch Foundation, aims to collect vital data on orca and other cetacean (whale, dolphin and porpoise) species found off the North East Scotland coast, as well as to inform the public about the abundance of marine life right on their doorstep! From the coast of Caithness, it is possible to see the visiting Type 1 North Atlantic orca cruising around the shores in search of food. During last year’s Orca Watch week, orca were spotted, as were several other cetacean species.

This year’s Orca Watch will take place from 21st – 28th May and all are encouraged to participate. You can find out how to get involved in the week, and in other events, by visiting Sea Watch Foundation, Caithness Sea Watching, Whale and Dolphin Conservation and Orca Aware.

During the week there will be ample opportunity to whale watch from Duncansby Head, Caithness alongside orca experts and fellow orca enthusiasts. While it is not guaranteed, there is a good chance that orca will pass by the shoreline during this time. I will be there, along with Sam, Orca Aware’s founding manager, and we hope to see you there too!

Photos (top to bottom): Orca off the Scottish coast sighted at last year's Orca Watch, Orca from the Icelandic population & Orca dorsal fin sculpture near Duncansby Head. 

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