Noxious Weed left to Spread

A NOXIOUS weed that could threaten fish stocks has been left unchecked to infest NSW waters.    And now the State Government has admitted that the invasion by caulerpa taxifolia - originally an aquarium weed - is so bad it will never be eradicated.

Commercial fishing crews and anglers said they feared the weed was altering the food chain by killing native seagrasses and sucking oxygen from the soil, thereby affecting native marine life.

There is no doubt in my mind that this weed will affect commercial and recreational fishing stocks because, wherever it's occurred, we've seen a depletion of fish," Pittwater professional fisherman Keith Sewell said.

Keith Sewell

Alarm bells about caulerpa, considered one of the world's 100 most noxious weeds, started ringing in 2000 but the Government and the Department of Primary Industries have been accused of simply watching the weed spread instead of stopping it.

DPI's aquatic bio-security manager Jane Frances denied the Government had dropped the ball.

But she admitted caulerpa was now so prevalent it was "not able to be eradicated in most estuaries where it exists".

And while, she said, the weed was "not causing as much impact on fish as initially feared" she also told The Daily Telegraph it had a "potential impact on native seagrasses which are the nursery ground of native fish".

Caulerpa is now in 14 waterways along more than 600km of the NSW coast from Lake Macquarie to Wallagoot Lake on the far South Coast.

Former Opposition environment spokesman and Castle Hill MP Michael Richardson, who has been attacking the Government on the issue for six years, blamed that outcome on a lack of investment in eradication initiatives.

"If this Government had tackled caulerpa with the same money South Australia did, then we wouldn't be in this position," Mr Richardson said.

SA has spent up to $500,000 a year to control and eradicate caulerpa since 2005.

Its government spent an additional $500,000 on a study into the ecological consequences of the weed, due for release in September.