While others have condemned Warrnambool City Council’s cautious approach to any upgrade at the harbour, Dr Sherwood said it was the right move. 

“The history of the Warrnambool harbour, and the harbours around us should give everyone a node of caution about how we proceed,” he said. 

Dr Sherwood said any development could have positive and negative impacts on the environment, with caution and science-based decision-making needed to ensure no irreversible damage was done. 

“When you look at the options for a new spur breakwater or for a fully enclosed harbour, they have the greatest potential for environmental impact,” he said. 

“We need to model wave direction in any final design. As we saw with configuration dredging, if we change the wave pattern, we can change where the erosion occurs on the beach.

“What we might find is we have potential erosion problems in different places along the beach because of the design we put in place. There was a similar issue in Portland along Dutton Way.”  

He said marine pests may also be able to get a toe-hold in the harbour and if that happened, the adjacent Merri Marine Sanctuary may also be at risk. 

Warrnambool’s Coastcare Landcare group also raised the issue, saying some harbour developments had led to environmental damage through changed wave and sand movements and the introduction of pest species. 

“Calm water may allow pests to become established,” Dr Sherwood said.

“That’s something we have been spared so far because they don’t really like high energy environments. That concern is highest with option C, the fully enclosed harbour.

“There are already nine introduced species in Portland harbour, and Apollo Bay has a terrible problem with an introduced seaweed. 

“The sad fact is you can’t manage that. I don’t think there are any really successful examples of eradication of marine pests in harbours – once they get in you can’t really get rid of them.”

But he said it wasn’t all “doom and gloom” and adding new hard surfaces, like sea walls and breakwaters, could also have benefits. 

“You are creating a reef, which is attractive to a whole range of organisms,” he said. “So you would get a win by increasing biodiversity.” 

Dr Sherwood said a longer “northern wall” in an enclosed harbour would collect sand and create extra beach. 

“You could create extra amenity for other beach users, you could create a beach down low, out of the south-westerly wind. The board riders are excited about potential shore breaks. They are things we would need to look at.”