Wednesday 17 November 2021

Cauliflower coral decline putting Port Stephens food chain at risk

BY DAKOTA TAIT

A decline in coral habitats off Port Stephens and the Central Coast could spell doom for local ecosystems.

Some habitats of the so-called cauliflower coral Dendronephthya australis are predicted to have declined by up to 90 percent - the species is the first soft coral in Australia to be labelled as threatened.

Researchers at the University of Newcastle found that while fish don't feed on the corals themselves, they do feed on other marine animals and invertebrates that do.

Dr Vincent Raoult says it's this simple fact that puts the entire food chain at risk.

"We found that a lot of the small organisms that live on or within the soft corals actually get most of their food from eating that soft coral," Dr Raoult said.

"What's important about that is, is that those small animals, they're important food sources for those larger fishes."

It's believed natural sand movements and the freshening of water from rain events, as well as human interference from boat anchoring and fishing entanglement, has triggered the decline.

But Dr Raoult says it's not too late to change our habits and turn things around.

"One of the things that's very important to do is to monitor those populations, to note the exact extent of the habitat of soft corals," Dr Raoult said.

"We need to try and explore other areas to see if they occur anywhere else, and Port Stephens Fisheries are developing a whole project to try and grow the soft corals in lab conditions, so they can be replanted in those lost habitats."

Image credit: marine.nsw.gov.au