Caulerpa taxifolia is back in Lake Macquarie

I was wading the water's edge, fishing at Green Point on the northern end of Lake Macquarie last month when I noticed a patch of unusual, bright green seaweed amongst the Zostera seagrass.  I thought it looked suspiciously like the introduced, invasive sea weed, Caulerpa taxifolia.  So I notified NSW Fisheries via their reporting interface
( http://www.dpi.nsw.gov.au/fisheries/pests-diseases/aquatic-pest-sighting ) and a week later an Aquatic Biosecurity Officer rang me to discuss my sighting.

There are several native species of Caulerpa that are endemic to the area, so I wasn't too concerned initially.  The officer rang me back yesterday, and my heart sank.  It definitely is Caulerpa taxifolia and the patch is around 100 metres in circumference.

From the NSW Fisheries website;

" Caulerpa was first found in NSW in April 2000, and it has now been detected in 14 NSW estuaries and lakes and one small oceanic population. Caulerpa is a Class 1 noxious species in all NSW waters under the Fisheries Management Act 1994. It is illegal to possess or sell the alga; fines of up to $11,000 apply. The noxious listing also provides NSW DPI with the power to seize and destroy Caulerpa, or require its destruction.  The invasive nature of Caulerpa has raised concerns as it has the potential to grow rapidly, alter marine habitats and affect biodiversity.  Aquatic pests, including Caulerpa are usually extremely difficult to eliminate once they have become established in the wild. It is therefore important to prevent noxious species such as Caulerpa from entering new waterways."
(Source URL - http://www.dpi.nsw.gov.au/fisheries/pests-diseases/marine-pests/nsw/caulerpa-taxifolia )


Lake Macquarie has been declared free of Caulerpa since 2009.  The graphic below lists some of the previously known occurrences.  This clearly illustrates how important it is to monitor for an invasive pest species for years after apparent successful eradication.

Historical known distribution of Caulerpa taxifolia
(Source URL - http://www.dpi.nsw.gov.au/__data/assets/pdf_file/0020/180641/Lake-Macquarie-2011.pdf) 

The good news is, the Authority responsible for managing the marine pest is now aware of the re-emergence of this species, and will monitor the Green Point population.  Yesterday Fisheries released an alert to the public.  Here is the link to the media release;
http://www.dpi.nsw.gov.au/aboutus/news/all/2015/lake-macquarie-users-urged-to-be-on-the-lookout

For more information about Caulerpa, visit the page on the pest at the NSW Fisheries website here; http://www.dpi.nsw.gov.au/fisheries/pests-diseases/marine-pests/nsw/caulerpa-taxifolia