The fin whale stranded near Ballinskelligs, Co Kerry was visited by IWDG Strandings Officer Stephanie Levesque under the Deep Diving and Rare species Investigation Programme (DDRIP). DDRIP was initiated by the IWDG in 2022 in response to a well-documented increase in recent years in cetacean stranding records reported through the IWDG Stranding scheme.
These include rare and deep diving species, particularly individual Sowerby’s and Cuvier’s beaked whales, both live strandings and dead. Mass strandings of deep diving species, which have been considered Unusual Mortality Events (UME), have also increased, the cause(s) of which remain unknown. This rise in stranding records has led to an increased awareness of these animals, especially beaked whales (family Ziiphidae), and the potential offshore pressures they are experiencing.
Rarely stranded deep diving species:
Cuvier’s beaked whale (Ziphiuscavirostris); True’s beaked whale (Mesoplodon mirus); Sowerby’s beaked whale (Mesoplodon mirus); Northern bottlenose whale (Hyperoodon ampullatus); Sperm whale (Physeter macrocephalus); Pygmy sperm whale (Kogia brevicep); Dwarf sperm whale (Kogia sima)
Rarely stranded, non deep-diving species:
Fin whale (Balaenoptera physalus); Humpback whale (Megaptera novaeangliae); Killer whale (Orcinus orca); Risso’s dolphin (Grampus griseus); White-beaked dolphin (Lagenorhynchus albirostri); Atlantic white-sided dolphin (Lagenorhynchus acutus)
Following an analysis of historical stranding rates archived in the IWDG Stranding Database (McGovern et al. 2017) particularly between 2017 and 2021, we estimate that there will be an average of eight animals suitable for necropsy per year. It is unlikely that it will be possible to carry out a post-mortem on all animals reported in suitable condition as unfavourable weather conditions, as well as the size and location of the animal, may limit accessibility to the carcass. Therefore, we estimate that five of the eight animals stranded in fresh condition would be collected for post-mortem examination.
DDRIP aims to carry out full post-mortem examination of a number of target species including fin and humpback, whales which are not rare but not frequently stranded. To carry out a post-mortem to establish cause of death requires trained veterinarians and the carcass to be in good condition. Unfortunately this individual was too decomposed for a full post-mortem. Stephanie collected a number of samples useful for biological studies but not able to establish cause of death.
The whale was a male measuring 19m in length which would have made it not fully grown. Samples of skin, blubber and baleen were taken.
For the disposal of animal remains, five options are currently available – the decision of which method to use will rest with the Local County Council or Vet lab:
1) Bury on site
2) Tow out to sea
4) Disposal at Vet Lab
5) Remain on site
Following a conversation with Kerry County Council they are intending to let it remain on site as the land is private and it is quite secluded.
During the first year of DDRIP the IWDG examined six animals were collected and examined under DDRIP: one white-beaked dolphin (Lagenorhynchus albirostris) from Co. Mayo, one pygmy sperm whale (Kogia breviceps) from Co. Donegal, one dwarf sperm whale (Kogia sima) – a new species to Ireland – from Co. Cork, one True’s beaked whale (Mesoplodon mirus) from Co. Kerry, one Cuvier’s beaked whale (Ziphius cavirostris) also from Co. Kerry, and one Sowerby’s beaked whale (Mesoplodon bidens) from Co. Mayo. Four animals were recovered to Regional Vet Labs (Athlone and Cork), while two animals were examined on site due to the inability of the RVLs to accommodate them due to their large size.
DDRIP is part-funded by the National Parks and Wildlife Service of the Department of Housing, Heritage and Local Government.