THEY slice through flesh like a scalpel, but it’s the blood in the water that is usually the first sign of their presence.
Not sharks, but razor clams and their numbers are proliferating across Lake Macquarie.
Lake Macquarie City Council is working with marine ecologists from the University of Technology, Sydney (UTS) to learn how best to manage the fan-shaped clams, which bury themselves in soft sand where seagrass grows.
The camouflaged clams can grow up to half a metre long and have thin, sharp, protruding lips which have claimed the skin of many unsuspecting swimmers and boaties.
Simply removing the molluscs might trigger a negative ecological reaction, UTS marine ecologist Dr Peter Macreadie says.
‘‘At the extreme we could end up with some sort of ‘ecological meltdown’,’’ he said.
‘‘Or maybe nothing will change and life will go on as usual.’’
The council wants to manage the risk, rather than eradicate razor clams, says Lake Macquarie council’s Ecosystem Enhancement Coordinator, Symon Walpole.
‘‘We would prefer to leave the natural ecology alone but we have to manage risk especially in places like enclosed swimming areas,’’ he said.
While the boom in the number of razor clams – also known as razor fish – over the past decade is a risk to swimmers, they also provide important scientific data.
The clams can live up to 18 years, and their shells have growth rings similar to trees, which can be used for scientific analysis.
‘‘They may act as time machines to the past and so could be used as pollution bio-indicators,’’ Dr Macreadie said.