West Coast Community Killer Whales

Four members of the West Coast Community orcas. Photo provided by the Hebridean Whale and Dolphin Trust.

### Common Features

Tall dorsal fin, eyepatches that slope downwards towards the back, large body size.

### Distribution

Hebrides, west coast of mainland Scotland with confirmed sightings in the waters surrounding Ireland, west coast of Wales, Moray Firth, and Aberdeen.

### Notable Individuals

* W001 "John Coe"
* W008 "Aquarius"

## Conservation

### Threats

Anthropogenic pollutants, lack of genetic diversity

The West Coast Killer Whale community is a small, critically endangered population of orca primarily found in the waters surrounding mainland Scotland and the Hebrides. At the time this population was first observed in the 1980's there were thought to be around twenty unique individuals within the population. In the 1990's, this number went down to fourteen. Only ten killer whales from the West Coast Community were cataloged when the Hebridean Whale and Dolphin Trust began studying them in 1992, and only two individuals (W001 "John Coe" and W008 "Aquarius") remain as of 2023.

## Population

The ten killer whales originally cataloged by the Hebridean Whale and Dolphin Trust in 1992 consisted of five females and five adult males. The adult males were W001 "John Coe", who is one of the two still-remaining whales, W002 "Floppy Fin", W004 "Moon", W005 "Comet" and W008 "Aquarius", who is the second remaining whale. The females were W003 "Nicola", W006 "Lulu", W007 "Moneypenny", W009 "Puffin" and W010 "Occasus". This population was never observed interacting or associating with other groups of killer whales and no female within the population was ever seen with a calf.

## Threats

The main threats that have caused the downfall of this small population are believed to be heavily linked with persistent exposure to anthropogenic and environmental pollutants such as PCBs. The West Coast Community feeds exclusively on marine mammals such as other cetaceans. Feeding at such a high trophic level has made this population more susceptible to these environmental pollutants that has been passed down to them through their prey. Anthropogenic pollutants such as these are known to suppress immune system functions and cause infertility. After the death of W006 "Lulu" a necropsy was performed on her which revealed her sum PCB level to be one hundred times higher than the toxicity threshold for physiological effects in marine mammals. Other threats such as severe lack of genetic diversity are also linked to the decline of the West Coast Community. After the necropsy of W006 "Lulu", genotyping of her DNA suggested that she was highly inbred. This population is considered functionally extinct as the only remaining individuals are both males.

## Identification

Killer whales of the West Coast Community are physically larger than other killer whale populations found in Scotland. Their eyepatches slope down towards the posterior end and the males have a tall dorsal fin. Photo cataloging efforts within this population began with the Hebridean Whale and Dolphin Trust in 1992. The West Coast Community killer whales are included in ID catalogs for all of Scotland's killer whales.

* Killer whales of Scotland (2021) ID Catalouge.

## References

1. ↑ 1.0 1.1 'Scullion AJ, Harrop H, Munro K, Truluck S & Foote AD (2021) Scottish Killer Whale, Orcinus orca, Photo Identification Catalogue 2021.'