Toulmin, who is one of three local photographers behind Patient Eye Images, captured this image on Levy's Beach near Warrnambool around 9pm on Tuesday using a long exposure.

The department of environment and primary industries (DEPI) yesterday warned people to keep their distance from the fin whale.

DEPI's biodiversity officer Mandy Watson said the whale was a young female measuring 16 metres and weighing an estimated 25 tonnes.

"The whale appears to have died recently, however the cause of death is not obvious," Ms Watson said.

"DEPI is investigating the possibility of collecting the rare specimen and other options for the carcass."

Fin whales are not uncommon in the waters off Portland where they feed in the Bonney Upwelling - a marine phenomenon in which nutrient rich water flowing up from the ocean floor triggers a bloom in phytoplankton and providing food for a whole range of species.

Ms Watson said the dead whale could attract sharks.

"It is recommended that surfers, swimmers, divers and fishers avoid the area around the deceased whale," she said.

"Warning signs have been erected."

She said it is also an offence to touch or take any part of a whale, whether alive or dead.

As for the photo, Mr Toulmin said he was able to achieve the effects in the photo without using editing software.

"It is a long exposure - 30 seconds - at a high ISO 3200," he explained.

A high ISO or International Standards Organisation number such as 3200 means the light sensitivity is higher than usual.

"It's pretty much straight of the camera (aside from) some cold white balancing.

"There was no extra light source used.

"I angled the shot so the lights from Port Fairy would light the scene for me."