Blue whale pooing in Geographe Bay captured on camera

A blue whale takes a poo while it swims past Geographe Bay. Photo by Ian Wiese.
A blue whale takes a poo while it swims past Geographe Bay. Photo by Ian Wiese.

A blue whale taking a fluorescent yellow poo in Geographe Bay in WA's southwest was captured by a drone while Dunsborough photographer Ian Wiese undertook research work.

Mr Wiese captured the image on Tuesday November 12 when he was filming a blue whale with his drone under a research permit which allows him to fly above the whale.

"It suddenly started having a poo," he said.

"Surprising as it may sound this is really important information as this video and others show that these blue whales on their journey from Indonesia down the WA coast are eating along the way, probably within 100 nautical miles of Geographe Bay.

"The really surprising thing was that it was a bright yellow color, and this has attracted a lot of attention with many jokes about Indonesian curries and so on.

"Normally blue whale poo is red or pink (from the color of the krill they eat) and this is the first time I can find any reference to a blue whale doing a high vis yellow poo."

Southwest Whale Ecology Study scientist Chris Burton said the colour of the poo was most likely caused by the whales diet which could have been a particular species of krill or it could have eaten something else.

"It could have been another small fish, or crustaceans, or squid," he said.

"As far as we know though, blue whales are one of the most specific predators of krill and they have not been observed eating anything else.

"It could have something to do with a different species of krill and there are a number around WA.

"It depends on the oceanographic conditions.

"It would have eaten within a 24 hour period, which would likely have been anywhere from Jurien Bay and south."

Mr Burton said it was a bit of a mystery and the only way to tell anything else would be by sampling the poo, if you were lucky enough to be in a boat to see that and take a sample.

"The poo looks iridescent, I has standing next to Ian at the time, I could see it was a very vivid yellow," he said.

"We now have around half a dozen records of this from this season, and not only of blues but also southern rights and humpbacks.

"We only have a tiny sample of the whole lot that goes on, we cannot see it that well from Point Piquet, even though I have seen a whale poo from there.

"You just see a big stain in the water."

Mr Burton said so far this year they had seen 175 blue whales swim passed Point Piquet which was up on the 10 year average of 130.

"We had a really big year in 2016 with 250 blue whales, that was a long migration," he said.

"Hopefully between us research groups we take enough photo identification so we can do some matching and get some research science between the areas, which would be really interesting."