Quick Dips

Whale Meat Again

Massey University's Cetacean Investigation Centre recently welcomed a full-time whale researcher to its team -- the first full-time cetacean pathology position in the world.

Irish pathologist Padraig Duignan accepted the Massey two-year postdoctoral position after an international advertising campaign. His last post was at the University of California Davis where he was a resident pathologist.

Duignan's PhD thesis was on morbillivirus infection in marine mammals. Morbilliviruses are related to human measles and canine distemper, and cause distemper-like diseases in seals and dolphins. Before 1988 they were unrecognised by science, but a series of epidemics in Western Europe between 1988 and 1992 killed thousands of seals and dolphins and brought the viruses to the attention of scientists.

Duignan's research showed the viruses were long established in many marine mammal populations in North American waters, with epidemics occurring in harbour seals and bottlenose dolphins.

"I found evidence of infection in seals, walruses, dolphins, whales and manatees from the Canadian Arctic through to the Gulf of Mexico, with the epidemiology closely reflecting the life-history characteristics of the host species."

When a population is infected, many animals die in the ensuing epidemic, but the remaining animals have immunity and are protected from reinfection. However, the population immunity decreases over time as new animals enter the population each year. Eventually it becomes susceptible again.

Duignan says the scenario reflects what was observed for gregarious species such as harbour seals and bottlenose dolphins that have fragmented populations along the United States coast. "In species that are more numerous and widely dispersed, such as pilot whales, there is endemic infection with consistently high population immunity and little mortality."

Duignan and project co-ordinator Dr Jane Hunter, of Massey University's Department of Veterinary Pathology and Public Health, will survey as many stranded animals as possible to determine the prevalence of infectious agents such as bacteria and viruses. This will involve a collaborative effort between Massey University, the Department of Conservation, the Museum of New Zealand and local iwi. The Massey team will focus initially on single-stranded dolphins and whales and net-caught seals. The latter will be examined under a DoC contract awarded to Hunter and fellow team member Per Madie.

Hunter says the results will provide a database on the health status of New Zealand marine mammals for comparing similar data from North America and Europe.

"And given that New Zealand is perceived to have a pristine marine environment, it will be of interest not only to New Zealand but also to the international scientific community."

Duignan will use the investigations to build an archive of tissue samples.

"Researchers interested in marine mammal diseases in years to come will be able to use these samples for retrospective studies as I did in North America using samples archived by people who had the foresight to collect them."

Samples will also be available for studies such as exposure to marine pollutants and for population genetics and systematics.

"We are basically starting from a level playing field so we will try and build up an information bank that we can share with collaborating researchers here or overseas."

Madie says Duignan's employment sends out a strong message.

"It shows the rest of the world that we are committed to wildlife and marine mammals.

"It's something we've been dreaming of for a long time. All other members of the group have full-time jobs in other areas. As the group has expanded it has become more obvious that a full-time position needed to be established."

The new position is funded by the Massey University Research Fund.