Loss of vital underwater forests happening 'out of sight, out of mind', marine experts say (2024)

Thousands of kilometres of underwater forests experts describe as a "biological engine" are under threat of disappearing unnoticed, with potentially devastating implications for hundreds of marine species.

University of New South Wales marine ecologist Adriana Verges said kelp forests that surrounded 70 per cent of Australia's coastline were progressively being lost due to warming waters, pollution and overfishing.

Concerns have also been raised that conservationists lacked funding for research and action to reverse the trend.

"Imagine if you lost an entire forest next to one of Australia's biggest cities," Professor Verges said.

"There would be public outcry, there would be marches, there would be protests, but the same thing can happen underwater and it can take decades before somebody even notices."

The condition of global kelp forests has been outlined in the State of the World's Kelp report, launched at the COP16 Convention on Biological Diversity in Colombia held at the end of October.

The report found the world was only 2 per cent of the way to meeting a conservation goal of restoring 40 per cent of the ocean's kelp forests by 2040.

Conservation efforts globally have included removing damaging species from kelp forests, transplanting kelp to promote growth and removing pollution from the ocean.

Professor Verges said damage to kelp forests could be hard to visualise, as it happened "out of sight, out of mind".

"There's a lack of knowledge and understanding, even though Australians are super connected to the ocean, it's kind of a surface connection," she said.

"We actually know remarkably little about what's under the waves and in particular in colder water ecosystems."

Professor Verges said warming waters due to climate change, pollution and overfishing were the main threats globally to kelp forests.

"A lot of kelp species need very cool, nutrient-filled waters to thrive and with climate change we have things like the East Australian Current pushing warm water down towards Tasmania," she said.

"It's pushing water that has less nutrients, it's warmer and isn't suitable for kelp growth."

Funding research gap

The Great Southern Reef is an interconnected series of kelp forests spanning around the 8,000-kilometre coastline of southern Australia.

The concept of the reef was put forward more than a decade ago to give a singular identity to the marine environments and push for more research and funding.

Great Southern Reef Foundation director of education and impact Stefan Andrews said unlike the famous Great Barrier Reef, the Great Southern Reef was still relatively unknown by the general public.

He said the Great Southern Reef had received about 2 per cent of the research and conservation funding of the Great Barrier Reef.

"What's happening to our kelp forests is they're changing and very few people are noticing those changes," Mr Andrews said.

"One, because there's just not as many people in the water and observing them, but also because some of these waters are so remote in many cases they're really hard to get to.

"The water is cold, the research is expensive and much more limited compared to coral reefs around the world."

Mr Andrews said around 70 per cent of Australians lived within 50km of a kelp forest, but not many knew their importance.

"It's right there on your doorstep," he said.

"The more people get in the water and just embrace it and be part of it, the more people value how special it is and want to protect it."

Locals leading the way

Along South Australia's Limestone Coast, the southern rock lobsters living in kelp forests are vital to the town of Port MacDonnell because of the town's lucrative fishing industry.

The waters off South Australia have the most seaweed biodiversity in the world, in part due to the Bonney Upwelling, which brings cold and nutrient-rich water from Antarctica to SA's coast.

Locals Sally O'Connor and Jo Fife founded The Holdfast Limestone Coast, which started as a seaweed art exhibition and has grown into an advocacy and citizen science group for local kelp forests.

The group braved chilly mornings to collect seaweed samples from the beach, before cataloguing them on an international database and turning them into art.

Ms O'Connor said the project aimed to create a link between passionate coastal residents and researchers.

"It's in our backyard and my backyard, so let's learn how we can celebrate it and how we can protect it," Ms O'Connor said.

"What we're wanting to do is transpose everyone's idea of smelly old seaweed, to something that is beautifully artistically and very important to our environment and economy."

The State of the World's Kelp report found South Korea and Japan were leading the way in restoring kelp forests, while Australia was fourth.

Professor Verges said all countries needed to take action to ensure their ongoing survival.

"We say it's a bit like the biological engine of shallow reefs, it provides organic matter, it recycles nutrients, it captures carbon and it provides a home for hundreds of species," she said.