UK Orca Pair Sighted Further South Than Previously Recorded
A pair of orcas have been spotted off the coast of Cornwall, the first time that they have been recorded in the UK's most southerly waters.
The orcas, a pair of adults named John Coe and Aquarius, were spotted offshore near the Minack Theatre – a large, open-air theatre situated on the cliff-tops near Porthcurno, Penzance, Cornwall – by members of the Cornwall Wildlife Trust's citizen science Seaquest Southwest team.
John Coe and Aquarius are two male members of the West Coast Community, the UK's only known resident pod of orcas. The two other males are Floppy Fin and Comet, the females of the pod are Nicola (thought to be John Coe's mother), Moon, Moneypenny, and Occasus. A ninth member of the pod – Lulu – was found entangled and stranded on the Isle of Tiree in the Scottish Hebrides in January 2016.
The pod is identified by an unusual slope to its large white 'eye patch', and members of the group are larger than other orcas. Individuals are identifiable through their unique fin shapes – the picture showing the lengthy and slightly crooked fin of Aquarius, according to the Hebridean Whale and Dolphin Trust's (HWDT) West Coast Community catalogue, which also notes that John Coe and Aquarius are often spotted together.
The West Coast Community was has been monitored by the HWDT since 1992 – with the first sightings reported as far back as 1977 – but sadly, it is thought that their future is bleak. Some members of the pod have not been seen for several years and there have been no new calves sighted within the group since monitoring began. Responsibility for the pod's infertility is thought to be largely man-made. A necropsy performed on Lulu in 2016 showed that she had never been pregnant, and her body contained a high level of PCBs (Polychlorinated biphenyls) – chemicals once used in the manufacture of electrical equipment, hydraulic fluids and lubricants.
Although their manufacture was banned in the 1970s, PCBs do not easily degrade and persist in the environment for years. They are known to cause infertility and, when Lulu's body was examined, it was found to contain 950mg of PCBs per kilogram of body mass – more than 100 times the 'safe' level of contamination.
It is also thought that the West Coast Community is genetically distinct from its North Atlantic Orca 'Type 1' relatives, which are more abundant and range between Iceland, Norway, and the northern Scottish islands. As male orcas generally do not mate with females from the same pod, and different orca types do not tend to mix, infertility and isolation are slowly driving the UK's resident pod of orcas to extinction.
Orca sightings around the UK are rare, but any and all cetacean sightings can be reported to a number of organisations, including on the Wildlife Trust's sightings and stranding page, and the Hebridean Whale and Dolphin Trust's sightings page.