Concern has been raised over the possible impact of proposed Chatham Rock Phosphate’s mining activities for phosphorite nodules on the crest of the Chatham Rise on the larval, post-larval puerulus, and benthic phases of red rock lobsters, Jasus edwardsii.
Due to the restriction of juvenile and adult phase red rock lobsters to depths less than 250 m it is unlikely there will be any direct impact of the proposed mining operations at ~400 m depth on rock lobster populations around the Chatham Islands.
Recent published research that modelled rock lobster larval sources and settlement localities strongly suggests that the Chatham Islands do not contribute significantly to the pool of lobster pueruli settling around mainland New Zealand. In contrast, the same study suggests that the Chatham Islands are heavily dependent on the east coast of mainland New Zealand as sources of lobster larvae, especially the area from Kaikoura to Cape Kidnappers.
The modelling of larval pathways suggests that for most of the long larval phase, lobster larvae that eventually settle around the Chatham Islands are entrained in eddy systems well to the north of the Chatham Rise. They are highly unlikely to spend time over the crest of the Chatham Rise in areas potentially affected by sediment plumes produced during mining activities.
Full report
[mappress] Press Release, April 24, 2013