v8-coupe wrote: Fish Addict wrote: Hopefully the mana whenua, as guardians of the NZ coastline will find a solution without needing monetary grants from the other 85%. Think I heard somewhere they, the marine scientific community, are going to try placing chlorine tablets around the area and then covering that area with a tarp/cover so hopefully, the dissolved chlorine only affects the area concerned. Believe it to be only a trial at present. Here's hoping.

They tried salt by the ton then covered with sacking,but too costly

The salt application method is an absolute joke. If you have to apply 50 kg/m2 then that is 500,000 kg/ha (10,000m2) = 500 tonne/ha, with ag salt currently costing $330/tonne (Ballance Agri Nutrients - they may be able to get it a bit cheaper but it won't be much) this works out at $165,000/ha for the salt alone, plus probably that much again for labor, boat hire etc etc. If we say conservatively the cost of treatment is $300,000/ha coupled with the likelihood that there is probably several hundred hectares of infestation area already spread far and wide between Great Mercury Island and the Bay of Islands and growing all the time (it will spread faster than the area that can be treated - also this is something that will be run and administered by the public sector, so don't expect anything to go quickly or smoothly). 

https://www.mpi.govt.nz/biosecurity/exotic-pests-and-diseases-in-new-zealand/pests-and-diseases-under-response/exotic-caulerpa-seaweeds-caulerpa-brachypus-and-caulerpa-parvifolia-in-new-zealand/#maps-upper-north-island