The Department of Environment, Land, Water and Planning said sightings of southern right whales had been reported along the coast between Cape Nelson, near Portland, and Geelong.

Senior biodiversity officer Mandy Watson said since Sunday May 7 sightings had been confirmed at Cape Bridgewater, Cape Nelson and there had been unconfirmed reports at Port Fairy, Corio Bay and Warrnambool’s Logan’s Beach.

“As these giant mammals are critically endangered (on the Victorian Threatened Species Advisory List) in Victorian waters, it’s always encouraging when we have such a good start to the season,” she said.

“We’re hoping to see an increase in whale activity off Portland, as last year a mother and calf stayed in waters off Portland for the entire season.

“This could be a sign of population recovery in the area, as the whales historically frequented this area in large numbers before being decimated during commercial whaling in the early 1900s.

“This is always an exciting time of year, and whale watchers will no doubt have eyes fixed on Logan’s Beach Nursery at Warrnambool, hoping to see the first mother and calf for the season.”

Ms Watson said the department was already investigating reports of boats going too close to whales.

An exclusion zone around Logan’s Beach will come into force on June 1, meaning no high powered vehicles can enter the area.

“We know that whales react to the presence of boats, and mothers will move between their calves and boats or move calves away from boats, so this zone is for everyone’s protection,” Ms Watson said.

The officer reminded people that in other areas boats must remain at least 200 metres from whales, and jetskis 300 metres.