Donna and Daniel Vermolen were strolling near the Portland waterfront on Wednesday when they sighted a whale from the city's water tower lookout.

"We went to the harbour where it was headed and that's where I was lucky enough to have captured (a photo)," Ms Vermolen said.

They are among social media users who've helped the Department of Environment, Land, Water and Planning confirm the presence of southern right whales in Portland.

"The sightings were validated through information provided by citizen scientists, including images and video posted on social media," natural environment programs officer Mandy Watson said.

"We're excited that these appear to be the first sightings for the season in our region."

The whales migrate from sub-Antarctic waters where they feed, to the southern coastline of Australia in the cooler months of the year to breed.

People typically see them off the south-west coast from May until October, when they rest in waters off Portland, Port Fairy, Apollo Bay and the only established nursery in south-east Australia at Warrnambool's Logans Beach.

The whales are listed as endangered under the Commonwealth Government's Environmental Protection and Biodiversity Conservation Act 1999.

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