Application of salt to control invasive marine alga Caulerpa taxifolia in Narrawallee Inlet, New South Wales, Australia

  • Published source details Glasby T.M., Creese R.G. & Gibson P.T. (2005) Experimental use of salt to control invasive marine alga Caulerpa taxifolia in New South Wales, Australia. Biological Conservation, 122, 573-580


The invasive marine green microalga Caulerpa taxifolia was first confirmed in New South Wales, Australia, in April 2000. It subsequently spread to nine waterways, covering approximately 8.1km² in 2005. An experiment was undertaken in Narrawallee Inlet, New South Wales, to determine the effectiveness of different salt concentrations in killing C.taxifolia. (See Case 280 for efficacy of control at Lake Macquarie).

Study site: In Narrawallee Inlet, New South Wales (Australia), four sites colonised by the invasive alga Caulerpa taxifolia were selected in February 2003 for salt application experiments. The idea behind the experiments was to test the efficacy of salt application as a method of Caulerpa contol. Each site was in water 1-2 m deep, separated by about 100 m and within 500 m of the mouth of the inlet.

Treatments: At each site, six 2 x 2 m plots were marked and equally divided between three treatments: (1) 50 kg/m² salt covering the whole plot; (2) patches of salt applied to visible Caulerpa taxifolia; and (3) no salt control. The number of C.taxifolia fronds was counted in each plot prior to application of the treatment and then after four days, 27 days and 86 days.

The number of Caulerpa taxifolia fronds in both salting treatments were equally reduced after four and 27 days relative to the unsalted control. After 86 days, the 50 kg/m² treatment had reduced frond density by about 90% and the patch treatment by about 75% relative to the control.

Note: If using or referring to this published study, please read and quote the original paper. This is available from Please do not quote as a case as this is for previously unpublished work only.

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