AUS - Artificial reefs attract more fish than natural reefs, research finds
Researchers say man-made reefs attract more baitfish then natural reefs and draw in huge numbers of predators ideal for recreational anglers.
Iain Suthers is one of several professors from the University of New South Wales School of Biological, Earth and Environmental Sciences monitoring the effectiveness of artificial reefs compared to natural reefs.
"Because natural reefs get eroded and worn down, they don't have that vertical relief," Dr Suthers said.
"Some artificial reefs are around nine metres high … they have tall tailors — not tall enough to interfere with shipping of course, but tall enough to reach up to the surface waters where the plankton is.
"They create a habitat where small baitfish feel protected and have plenty of zooplankton to eat."
Baitfish – small foragers – flock to the structures in huge numbers.
"The little guys like sardines or what we call the yellowtail scad eat plankton and ultimately then feed the bigger fish that we like to eat," Dr Suthers said.
"They are food for big guys such as flathead, yellowtail kingfish, Australian salmon, tailor."
Dr Suthers said the research shows the importance of small fish in the ecosystem.
"Zooplankton and these small fish support around half of the fish biomass," he said.
"The structure ensures the small fish have a habitat, they feel protected, they can eat all this zooplankton — but of course they get hit by predatory fish.
"We've completed the link — we've completed the food chain."
Good catch for bottom line
NSW has artificial reefs at Sydney, Shoalhaven, Port Macquarie, Merimbula, Newcastle, Wollongong and Tweed Heads, and a ninth is set to be installed off Batemans Bay next month.
"Compared to other states, NSW has gone at this quite aggressively, because we have a big, urbanised coastline with many people wanting to go out and catch fish," Dr Suthers said.
"Unfortunately, the natural production just can't keep up — not only because of the impacts of fishing, but urbanisation and loss of habitat too, but we can actually enhance coastal fish production with these reefs."