Taxidermied and dummy sea lions could be used to lure hundreds of the world's most endangered sea lions to Victory Beach, on the Otago Peninsula, new University of Otago research suggests.
A study by University of Otago School of Surveying lecturer Dr Antoni Moore into the ocean and coastal management of New Zealand sea lions - formerly known as Hooker's sea lions - identified possible breeding colony sites for the species on the peninsula, and to a lesser extent in the Catlins.
At present there is no sea lion colony site on the Otago Peninsula.
Dr Moore said the sites, particularly Victory Beach, already had important environmental factors, such as proximity to coastal forest and estuarine habitats, which were favoured by breeding sea lions.
"This beach is located in an isolated area.
"There is no significant urban or road development nearby, and as such the threat of human disturbance at the site is low.''
Observation of females and their pups at Enderby Island, south of New Zealand, indicated females formed in groups of four or five female-pup pairs, with a group of five per hectare, Dr Moore said.
If such dispersal was replicated on Victory Beach, 14ha of pine forest behind the sand dunes could be home to 70 breeding females, he said.
Other females could occupy nearby dunes and shrubs to nurse their pups.
Smaller suitable sites were identified at Allans Beach and Sandfly Bay, Dr Moore said.
Research co-author Dr Louise Chilvers said while the research was only a preliminary indicator of possible suitable colony sites, dummy female sea lions and taxidermied females had been successfully used to attract other sea lions to Victory Beach.
"We have tried putting out female decoys to attract other females, because it is pregnant females that we want.
"They look to protect themselves from males so when they see other female sea lions they feel safe.''
Victory Beach was the main site chosen by female sea lions to nurse their pups in Otago.
Dr Chilvers said she had 16 years' experience working with the species and human interaction with the animals was viable.
"In Otago, particularly, there is potential for them to become quite a tourist attraction.
"In my experience, most negative experiences people have with sea lions are caused by human error. Obviously dogs don't mix well with them.''
Department of Conservation biodiversity ranger Jim Fyfe said having sea lions come back to the mainland was "like getting moa back''.
"It would be nice if a Victory Beach colony did happen because it is a tucked-away sort of place.''
However, it was crucial any tourism venture which may arise as a result of a colony did not threaten it.
"We might be able to achieve that without unduly stopping breeding from happening.
"If actually tourism is one of the threats, we would have to manage that fairly carefully.''
Otago Peninsula Trust marketing manager Sophie Barker said the trust preferred to direct peninsula visitors to Sandfly Bay and Allans Beach.
"While it's wonderful that we are getting sea lion colonies, there is a reason they are there and that is because we are not.''
Dr Moore said the research did not recommend putting any measures in place to control human disturbance to future colonies.
"We want to minimise human access as much as possible, while also allowing serendipity to come into play.‘‘It is a magical experience to come across a sea lion.''
The researchers used data gathered through the spatial analysis of potential suitable habitats from a 1600km stretch of the South Island's coast to identify the distance between features favoured by sea lions and urban disturbances, including roads.
At present the Department of Conservation and the Ministry for Primary Industries are seeking public feedback on a draft New Zealand sea lion threat management plan.
When completed, the management plan and further analysis of other possible colony sites in New Zealand would be considered before any mainland breeding colony was facilitated, Dr Moore said.
"If this was not to happen, then their distribution would be limited to only three breeding colonies in the subantarctic islands, making them far more endangered.''
● Other authors of the research are Hamish MacMillan and Dr Amelie Auge.
At a glance
• 11 sea lion pups were born around Otago Peninsula this year
• All Otago-born sea lions are descendants of a matriarch named "Mum'' whose pup was born on the Otago coast in 1993
• Population about 10,000
