Boaties asked to be alert for new seaweed

A red seaweed (Asparagopsis taxiformis) that is new to mainland NZ has been found at Iris Shoal on Kawau Island and Tamaterau in Whangārei Harbour.

Officials suspect it has been at these locations for some time, likely finding its way there on a vessel either associated with biofouling, on an anchor, anchor chain or dirty equipment.

A native of the Kermedec Islands, it is unknown how the red seaweed will react in the mainland NZ marine environment and, at this stage, there is no evidence to suggest that the seaweed is affecting biodiversity in these areas. However, internationally it has been shown to out-compete and displace native species.

Biosecurity is currently completing a risk assessment but, in the meantime, all vessel owners are asked to be extra vigilant and ensure hulls are clean before moving as officials suspect that it will be in other locations.

Anyone who finds the seaweed outside Kawau Island or Whangarei Harbour is asked to call the MPI exotic pest and disease hotline on 0800 80 99 66, or use the online report form http://report.mpi.govt.nz/pest.