Measuring more than 6.5 metres long, the accidental catch will now help scientists learn more about the elusive ocean giant.

The trawler’s skipper has donated the unusual find to Museum Victoria and senior collections co-ordinator Dianne Bray said they were thrilled.

The only specimens of a basking shark Museum Victoria currently holds date back to the 19th century.

“It’s very exciting,” Ms Bray said. “We currently only have skin and teeth from 1883 that also came from Portland.

“It must have come up by horse and cart and I imagine we only have the skin and teeth because it would have taken a long time to get to Melbourne. It would have been quite smelly by then.” Basking sharks are found worldwide, but Ms Bray said little was known about the species, which next to the whale shark is the second largest fish in the world. 

Despite its size and enormous mouth, the basking shark is harmless to humans. It uses thousands of bristle-like grill rakers to strain plankton from the water.

“There are very few in museums in Victoria,” Ms Bray said. “We really don’t know much about them.” 

The shark was taken from the trawler yesterday and is expected to be dissected by Museum Victoria scientists on the Portland wharf today.

Due to the shark’s size, it will not be able to be transported to Melbourne whole.

Ms Bray said scientists would collect the head and fins, which may be used to make a cast model for display.

Tissue and skin samples will provide information on the shark’s background and muscle tissue will be used in stable isotope studies to provide clues on diet and where the shark has been.

Ms Bray said the museum was lucky to have specimens of the endangered shark.

“It was caught by accident and it’s fantastic that they have offered it to the museum,” she said.

“We would rather see something in the ocean, everyone would rather see it in the ocean but this way it is preserved so that we and future generations can learn more about them.”