Locals in the south-west of Victoria are rallying against the use of seismic blasting by oil and gas companies, after a suite of proposals to conduct seismic surveys in coastal waters spanning the iconic Great Ocean Road coastline and beyond across the Gunditjmara Sacred lands and Sea Country.

Concerns over the impact of the practice on marine life in coastal waters are gathering momentum.

The Southern Ocean Protection Embassy Collective (SOPEC), which has organised a rally on October 22, said seismic blasting involved compressed air guns releasing underwater sound waves to record echoes off the geological formations below the seabed.

They are often undertaken in areas of cultural importance to First Nations people and could impact whales and turtles, which are of high cultural and ecological importance.

SOPEC said the practice had been shown to harshly impact marine ecosystems and raised concerns among marine biologists, environmentalists, First Nations groups, commercial and local fishermen, swimmers and surfers.

The planned rally follows a landmark ruling in the Federal Court last month that scuttled Woodside Energy's plans for its Scarborough LNG as project off north-west WA.

The energy giant had hoped to begin underwater surveying for the US$12 billion project off the Burrup Peninsula last month but was forced to delay those plans after a legal challenge from Mardudhunera woman Raelene Cooper, who argued she had not been adequately consulted.

The case followed a decision late last year by the Federal Court to overturn a key approval for Santos' $4.7 billion Barossa offshore gas project after it considered the way Tiwi Traditional Owner and Elder Dennis Murphy Tipakalippa was consulted by Santos.

Both Warrnambool and Moyne Shire Council in Victoria recently voted to oppose the plans and advocate relevant federal ministers and regulators on their behalf.

The SOPEC protest later this month comes four years years after record numbers of Warrnambool locals supported the successful Fight For The Bight campaign, which saw Norwegian oil & gas giant Equinor withdraw from the Great Australian Bight.

Gunditjmara woman and whale dreaming custodian Yaraan Couzens Bundle said seismic blasting companies were not genuinely engaging or understanding traditional custodians and their deep reciprocal kinship relationships with Sea Country.

"Traditional owner consultation is never about if a project goes ahead, only how and when," she said.

"No environmental plan put forward by any of these companies can truly measure the irreversible damage done by seismic blasting and then drilling into the ocean floor."

Deakin University marine science PhD candidate and protest organiser Zoe Brittain said the Great Southern ocean was a unique part of the world and home to a big, diverse range of species.

"When the seismic testing companies can't even show a basic understanding of high school science concepts during community consultations, it begs the question of how they can be trusted to thoroughly address more complex environmental concerns," she said.

Warrnambool City Council councillor Angie Paspaliaris said while she appreciated Australia relied on energy resources she believed it only had gas export problem.

"As far as I'm aware, almost 80% of Australia's gas is exported. So we have, and we have had plenty, we just aren't keeping much for ourselves," she said.

"[That] we should accept the idea of disturbing and impacting our marine environment to facilitate searching for more? To me it's a completely illogical concept."

SOPEC said no environmental plan could measure the damage done from seismic blasting across ancient and ancestral whale migration pathways and songlines.

The SOPEC rally Stop Seismic Blasting and Save Southern Sea Country is on October 22 from 2pm at Warrnambool Breakwater and is in conjunction with several film fundraising events its used to promote awareness of seismic blasting in partnership with Surfrider Foundation Australia new new documentary Southern Blast.

The film is a cinematic celebration of the wild landscapes, abundant marine ecosystems and local communities that call the Southern Ocean coastlines home, with beautiful footage shot on location in Lutruwita, Tasmania.

It explores the connections between the sea and local personalities, from surfers to crayfishers, sustainable ocean businesses and Traditional Custodians.

The unique and diverse communities that coexist with marine life and wild landscapes are highlights of the film, a showcase of the relatively untouched charm of Lutruwita and the threat posed by the fossil fuel industry.