Hair dye is helping conservation of WA’s sea lion population. 

An innovative new project is using human hair dye on Australian sea lions at Carnac and Seal Islands off the coast of Perth to track and learn about the local population.

“The hair dye marks are temporary and completely safe, just like hair colour on a human, but for a period of about two months it allows us to identify each sea lion and monitor how often they move amongst the six haul-out islands, such as Carnac Island and Seal Island,” says researcher A/Prof Chandra Salgado Ken. 

The marking method, which has been applied to other species of seals and sea lions elsewhere, is non-invasive and does not harm the animals in any way.

“A layer of dye is spread on numbers with foam material on them, and the numbers are mounted on a plate attached to a long pole, we then press the plate onto the sea lions back or side,” A/Prof Salgado Kent says.  

“The poles allow us to keep our distance to create minimal disruption to the sea lions.”

Satellite tags are also being deployed by the expert team.

“We are trying to better understand how many sea lions use the area and where they may be foraging,” says Department of Biodiversity, Conservation and Attractions (DBCA) marine researcher Kelly Waples.

“To do this we will be putting satellite tracking devices on a small number of sea lions.  These tags are a small package that is unobtrusively glued to the fur on their back just behind their shoulders and will be retrieved from the sea lions in a couple of months’ time before the animals fully moult.”

The satellite tags have already been successfully attached to four sea lions, who were also marked with the hair dye.

Male sea lions tend to move between breeding islands around Jurien and haul-out sites in the Perth metro area, many using the Perth Metro Area during non-breeding periods.

The satellite trackers will help obtain high resolution information on where they forage and what habitat is important for them to find and capture their prey.

By understanding which habitats are important, the researchers can get a better understanding of how to manage and protect this endangered species, which have experienced a more than a 60 per cent decline in numbers over the last 40 years.