Chatham Rock Phosphate Ltd. has advised shareholders that an ocean study by the NIWA (National Institute of Water and Atmospheric Research) announced this week is particularly relevant to the company’s proposed marine phosphate recovery operation on the Chatham Rise.
NIWA has advised that one of the most challenging scientific underwater experiments it has ever attempted is taking place this month on the Chatham Rise. At least nine separate highly specialized pieces of equipment will be deployed from NIWA’s research vessel Tangaroa, in water up to 500 metres deep. The equipment includes an underwater glider, three undersea observational platforms known as benthic landers, a multicorer to take sediment samples, seabed moorings, water column sampling equipment, an underwater camera that will be towed above the seafloor and a benthic disturber.
The aim of the voyage is to disturb a small area of the seabed and create a sediment plume using the benthic disturber. The dispersal of the plume will then be monitored, and surveys before and after the disturbance will measure the effects on the seabed animals. The data collected will be used to build up a picture of how the biological communities on the seabed may be affected by the sediment stirred up by mining or bottom trawl fishing.
Uncertainty about the effects of sediment plumes has contributed to applications for seabed mining being declined, and the plumes are also an environmental concern for sustainable fisheries certification.
“These activities create plumes of sediment, but we don’t know how the sediment affects seabed life as it settles again on the seafloor, and how much deep-sea animals can withstand. We are doing this experiment on a small scale on the Chatham Rise, but it will give us a much better idea of how environmental managers and industry can work to mitigate larger-scale disturbance effects,” noted NIWA scientist Dr. Malcolm Clark.
Chatham Rock Phosphate chief executive officer Chris Castle said: “Clearly the outcomes of the disturbance research are incredibly relevant to our project in that they will provide real data on the behaviour and effect of plumes generated when the seafloor is disturbed (by any activity, including dredging, mining and bottom trawling).
“We have already spent very considerable sums modelling how the plumes will behave, so we expect that this real data will further strengthen our ability to quantify these effects.
“We have been involved with the planning of this project and have a representative on board the Tangaroa to help carry out studies with the NIWA team. We also have other consultants that will be remotely monitoring some oceanographic data as it is generated that could assist the survey planning,” said Mr. Castle.
About Chatham Rock Phosphate
Ltd.
Chatham Rock Phosphate is the custodian of New Zealand’s only material resource of ultralow-cadmium, environmentally friendly pastoral phosphate fertiliser. The company’s key role is connecting the resource with those who need it.
Chatham takes very seriously the responsibility vested in it through its mining permit to use the world’s best knowledge and technology to safely extract this resource to help sustainably feed the world.
The company’s initial environmental consenting process independently established that extraction would have no significant impact on fishing yields or profitability, marine mammals or seabirds.
