Dingle dolphin Fungie was genetically a mix between Ireland’s Shannon Estuary bottlenose dolphin population and the much larger offshore population, a newly published study has found.
Fungie, who inhabited Dingle, Co Kerry for almost four decades and became one of Ireland’s best-known wild animals, disappeared in October 2020.
The study published in the international journal Ecology and Evolution concludes it is an unusual finding, as bottlenose dolphins sampled in Ireland tend to be genetically assigned to one distinct population or another.
The research by an Atlantic Technological University (ATU) team also revealed that four of five well-known solitary dolphins studied in Irish waters were genetically assigned to the offshore population.
Fungie was the exception, showing mixed ancestry between the Shannon Estuary and offshore populations.
The findings raise new questions about where Ireland’s solitary dolphins originate and whether their origins could provide clues as to why some move inshore, remain apart from other dolphins and develop close interactions with humans.
The research carries particular significance for the ATU team because it was led by the late Lorenzo de Bonis during his IMBRSea Master’s studies at ATU.
Lorenzo tragically died in a rock-climbing accident while finalising the work for publication. His colleagues subsequently completed the publication process in his memory and as a legacy of his contribution to marine research.
As Fungie had disappeared in late 2020, obtaining his DNA presented researchers with an unusual challenge.
The solution came from the Irish Whale and Dolphin Group (IWDG) member Denis O’Regan, who had regularly swum with Fungie, and had worn the same wetsuit during the swims.
Several areas of the wetsuit were swabbed, and samples were sent for analysis. Laboratory testing subsequently confirmed that the genetic material recovered was dolphin DNA rather than human DNA, allowing researchers to investigate Fungie’s genetic ancestry years after his disappearance.
Researchers examined the genetics of bottlenose dolphins in Irish waters using samples from stranded and free-ranging dolphins. They were particularly interested in solitary dolphins- individuals that live apart from pods and can sometimes develop close interactions with humans.
Five well-known solitary dolphins were sampled: Fungie in west Kerry, Nick in Cork Harbour, Finn in Carlingford Lough, Dusty in north Clare and Nimmo in Galway City.
Four- Nick, Finn, Dusty and Nimmo- were genetically assigned to the offshore population, while Fungie stood out because of his mixed ancestry.
Ireland has documented an unusually high number of solitary dolphins in recent decades, with bottlenose dolphins accounting for most of these individuals.
ATU PhD candidate and study co-author Seán O’Callaghan said the findings add an important new dimension to what is known about these familiar animals.
Dr Simon Berrow, lecturer at ATU and the founding member of the IWDG, who initiated the study, said why these animals become solitary remains an important unanswered question.
“Why these dolphins seek human company rather than socialise with other bottlenose dolphins has long been a mystery. Maybe they do not understand each other and use different vocal dialects, confounding communication, or perhaps they just have very different ecologies,” Berrow has suggested.
Dr Luca Mirimin, lecturer at ATU, who supervised Lorenzo and co-led the research, said:
“Publishing this work was important to advance our knowledge of such iconic marine mammals in Irish waters, but most importantly was a way to ensure that the work of Lorenzo was made publicly available to future generations of scientists.”
The research also demonstrates the potential of minimally invasive and innovative DNA sampling techniques to provide new insights into marine mammals without requiring animals to be captured or directly handled.
