Marine scientists warn biodiversity of Geographe Bay must be protected from over-fishing, nutrients and global warming.

Whale migration, climate change and marine science were just some of the topics discussed at GeoCatch's Geographe Bay marine seminar.

More than 70 community members turned out to hear expert researchers speak about the biodiversity in Geographe Bay, Ngari Capes Marine Park and surrounding national marine parks.

Dr Sahira Bell from the Department of Biodiversity, Chris Burton from Geographe Marine Research, ECU's Dr Tim Langlois and UWA's Professor Kathryn McMahon came together to present their research on seagrass, fish, marine parks, Leeuwin current, whale monitoring and citizen science.

Talking science: Chris Burton and Ian Wiese from Geographe Marine Research. Picture: Supplied.

Talking science: Chris Burton and Ian Wiese from Geographe Marine Research. Picture: Supplied.

As well as hearing expert knowledge, attendees saw footage of migrating whales, the Great Southern Reef and the seafloor from various depths off the coast.

Current research shows that Geographe Bay and the surrounding marine environment is relatively healthy but the experts warned that in the future it may be under threat from excess nutrients, over-fishing and warming sea temperatures.

Cr Ross Paine opened the event and said he was surprised by the amount of research being undertaken.

"It's encouraging to see how our understanding of the local marine environment is improving," he said.

"If we can track changes in the system, we can hopefully build more resilience to future pressures like climate change.

"Like many in the community, I feel lucky to have a healthy bay on my doorstep and want to ensure it's protected for future generations," he said.

Researchers say everyone can do their bit to protect the bay by reducing fertiliser runoff from gardens and farms, observing the marine park no-take zones and leaving a safe distance between marine mammals and motorised vehicles.

The seminar was supported by Royalties for Region's Healthy Estuaries WA and Revitalising Geographe Waterways programs.