Dr Catherine Collins has used DNA from ancient and modern
sea lion bones to determine endemic New Zealand sea lions
were different from the subantarctic sea lions which are
recolonising Otago's coastline. Photo by Gerard O'Brien.
Comparison of DNA from ancient and modern sea lion bones
has proved the sea lions which roamed New Zealand's coasts
centuries ago were genetically different from the subantarctic
sea lions which are recolonising Otago's coastline.
While it had been thought these earlier sea lions were of the
same species as those now returning to the mainland, research
from the University of Otago released yesterday has shown
that was not the case.
Using DNA from ancient bones, researcher Dr Catherine Collins
discovered the sea lions found around New Zealand hundreds of
years ago had different genetic material from those from the
That meant there was a unique, prehistoric sea lion roaming
New Zealand's coasts before becoming extinct about 600 years
''It's fascinating; really exciting findings,'' Dr Collins
It was estimated the sea lions became extinct between AD1300
and AD1500, soon after Polynesian settlement.
''Midden remains suggest they were hunted extensively.''
Their extinction then seemed to create an opportunity for sea
lions from the subantarctic to colonise New Zealand's
mainland, she said.
The research involved visiting different museums and
universities around New Zealand where ancient sea lion bones
are stored and extracting DNA from them in Otago University's
secure ancient DNA laboratory.
The findings echo the discovery in 2008, also by University
of Otago researchers using similar DNA investigations, of a
new penguin species, which was estimated to have become
extinct between AD1300 and AD1500.
Dr Collins said the study's findings helped give a greater
understanding of the impact of human arrival on New Zealand's
endemic plants and animals and it was expected additional
cases of extinction and replacement would be found.
''We predict that future studies will reveal additional cases
of lineage extinction and replacement in response to human
impacts, especially across recently colonised ecosystems.''
The Marsden-funded study was led by Prof Jon Waters, who said
the findings demonstrated the sea lions on Otago's coastline
today were not a declining remnant of an original mainland
''Rather [it] represents a new arrival from the
The findings were published yesterday in the research journal
Proceedings of the Royal Society B: Biological Sciences.