Analysis of organs from the orca killer whale which died in Cork Harbour two weeks ago could give insights into the movements and life pattern of one of the most beautiful creatures ever seen in Irish waters.
The public response to the presence of the orcas in the shallow waters near Cobh has been so great, says the Irish Whale and Dolphin Group, (IWDG) that whale-watching could become a popular pastime.
The female orca, about 50 years old and 30 feet long, died from a form of septicaemia caused by the bacterium staphylococcus aureus. Its teeth had become ground down, exposing pulp cavities which allowed infection to enter through an abscess of the lower jaw. Its lungs were affected by bacterial pneumonia and its kidneys were inflamed.
The initial autopsy on the whale was carried out by Mr Eugene Power, a senior veterinary research officer with the Department of Agriculture and Food in Cork.
Researchers at UCC's department of zoology, where further analysis is being carried out, believe the whale must have been in pain and that it had made for shallower waters where feeding on the plentiful shoals of fish would have been relatively easy at this time of year. It meant the whale could swallow its food whole without having to chew or rip flesh apart.
One theory is that the female was the dominant member of the pod of three orcas which arrived in Cork Harbour almost two months ago, and that the others, a male and a juvenile of unknown sex, followed it in.
Dr Simon Berrow, chairman of the IWDG, says whales, dolphins and porpoises, are a regular feature of the marine life around our coast. Even though one of the orcas died in Cork Harbour, their visit should be seen as an opportunity to bring the story of whales in Irish waters to a much wider public and to heighten awareness of the role everyone can play in conservation.
Some 23 species of whales and dolphins have been recorded around the coast, Dr Berrow says, adding that the orca is really just a big dolphin and the killer whale tag may be a misnomer.
Other whales sighted regularly include pilot whales, minke whales, fin whales, the second largest member of the whale family after the blue whale, and the blue whale itself, whose presence in the deep waters off Ireland has been established by acoustic monitoring. Humpbacked whales, sperm whales and bottle-nosed whales have also been recorded.
This month, whale sightings have been reported off counties Wexford, Donegal, Cork and Kerry. In May, there were sightings off the Antrim, Kerry and Galway coasts, and last month, the orca was seen in Killiney Bay. "Orcas can turn up anywhere at any time, they tend to be quite unpredictable. We are very fortunate to have such an abundance of whales off our coast. We should be enjoying and celebrating their presence more while helping the conservation effort at the same time," Dr Berrow said.
At UCC, Dr Emer Rogan, of the zoology department, is leading the Irish contribution to EU-funded research into whale strandings under the Biocet project. Why do cetaceans wash up alive or dead on our shores and is pollution leading to contaminants in the food chain a causative factor?
The three-year study began last January and also includes the Netherlands, France and Spain. The impact of contaminants on the reproductive cycle of females also forms part of the study. Mass strandings of whales or dolphins are not unusual, Dr Rogan adds.
In September 1994, 19 white-sided dolphins were found stranded on a beach in Killala, Co Mayo. Autopsies showed that with the exception of an older male which died from heart disease, the rest of the dolphins were in good condition. Was it the case that a navigation error was made by a senior member of the social group and the others had followed blindly to their death, or were other elements at work?
Why the teeth of the dead orca in Cork Harbour should have been so severely ground down remains a puzzle to zoologists like Ms Sinead Murphy, also of UCC, although the phenomenon has been noted before in the species. As part of the effort to learn more from the death, dorsal fin records of the whales seen in Cork will be passed on to international colleagues to determine if they have been sighted elsewhere.
UCC has been funded by a number of oil companies to study cetaceans and seabirds in Irish waters. The study has been ongoing since July 1999, but the oil companies have chosen to reveal further details only if they have first vetted any reports that may be written about it. This approach is more normally reserved for valuable exploration information.
The IWDG is constantly updating its website and all sightings of whales are automatically reported there. The address is http://iwdg .ucc.ie