TAKE CARE: Surfers are urged to use common sense before hitting the waves at Ballina’s North Wall, with dangers lurking beneath the water following the recent flooding.
TAKE CARE: Surfers are urged to use common sense before hitting the waves at Ballina’s North Wall, with dangers lurking beneath the water following the recent flooding.

Swimmers beware: 19 bull shark detections over weekend

SURFERS have been urged to use "common sense" before hitting the waves at Ballina's North Wall due to the dangers lurking beneath the murky water.

The duty officer for Surf Life Saving Far North Coast, Jimmy Keough, said not only were submerged objects coming out of the Richmond River following the recent floods, but it is well known that bull sharks haunt the mouth of the river.

And they don't mind the dirty water.

The NSW Department of Primary Industries SharkSmart Twitter feed reported 19 detections of tagged bull sharks were recorded by the Lighthouse Beach receiver over the weekend - though that doesn't indicate the number of sharks.

Mr Keough said bull sharks were always at the mouth of the river.

But he said the dirty water is reducing the visibility of the drone patrols over the water, which is one of the shark safety measures put in place by the State Government after Ballina became known as the "shark capital of Australia".

"The reduced visibility is hampering operations," Mr Keough said.

"The message is to use common sense.

"There are a lot of hazards (in the water)."

He said the SMART drumlines, which also are part of the shark mitigation strategy, were in and out of the water, depending on the sea conditions.

They were not in the water on Saturday or on Monday, according to the SharkSmart Twitter feed.

The DPI's helicopter patrol also didn't fly on Sunday between Ballina and Tweed due to inclement conditions.

Mr Keough said the decent swells over the weekend had attracted surfers to the waves near river mouths throughout the region.

One of the SharkSmart safety tips provided by the NSW DPI Department of Primary is to "avoid murky water, waters with known effluents or sewage."

While the tips also include avoiding river mouths, North Wall has been a popular spot for surfers for many years.