Ngā Motu Marine Reserve Society. List of Questions for Expert Witnesses. Trans-Tasman Resources Limited Sand Mining Application 2016

Transcription

1 Ngā Motu Marine Reserve Society List of Questions for Expert Witnesses Trans-Tasman Resources Limited Sand Mining Application 2016 The questions for the witnesses are provided below in bold blue text. We have also added some explanatory text to provide background on why the question is important. Sedimentation A number of the Expert Witnesses for the Applicant refer to the effect of the sediment deposition from the plume being indistinguishable from deposition from background except within a few kilometres of the mining activity e.g. Dearnaley paragraph 78, James paragraph , MacDiarmid paragraph 94. These conclusions are entirely reliant on the predictions of the sediment plume model being correct. It will not be possible to validate sediment deposition rates until the mining has commenced. Unlike suspended sediment concentrations, there are no quantitative response limits or consent limits proposed for sediment deposition rates or sedimentation. According to Dan Govier s evidence (paragraph 69) sedimentation rates will be measured at the permanent monitoring stations with sediment traps retrieved monthly. Compared to suspended sediment concentrations, it will not be possible to get the same coverage or frequency of measurements for sedimentation. Sediment Deposition Question: To be asked to Michael Dearnaley, Mark James and Philip Mitchell (time approx. 5 minutes) Quantitative response limits and consent limits have been provided for suspended sediment concentrations. Should quantitative response limits and consent limits also be provided for sedimentation? If not, why not? Primary productivity In his evidence, Lawrence Cahoon refers extensively to the significance of photoadaptation as a mechanism of how primary producers will respond to reduced light levels. It must be noted that photoadaptation requires the synthesis of additional pigments (Cahoon refers to synthesis of pigment-protein complexes p29) which comes at an additional energetic cost to the primary producers. Photoadaptation to reduced light levels will result in increased concentrations of chlorophyll a per cell. Under these circumstances it is questionable whether chlorophyll a provides a reasonable indicator of biomass, as the ratio of these two parameters will alter. Within his evidence, Daniel Govier outlines the monitoring protocol for primary producer biomass. On page 58, paragraph 206 Govier states that chlorophyll a will act as a proxy for phytoplankton biomass. There will be no direct measurements of primary production (growth, carbon fixation or rate of photosynthesis) as part of the monitoring programme and TTRL do not intend to use a modelling approach to assess the impact on primary production downstream of the mined area. The Society is of the opinion that the inadequacy and uncertainty of information with respect to reduction in

2 primary production as a result of the sediment plume raises serious concerns in terms of impacts within the wider ecosystem. Primary Producer Questions: To be asked to Lawrence Cahoon and Daniel Govier (time approx. 5 minutes) If photoadaptation occurs in response to reduced light levels, will chlorophyll a act as a reliable proxy for biomass taking into account changes in chlorophyll a:biomass ratios? TTRL do not intend to measure primary production or use a modelling approach to assess the impact of the plume on primary producers. Is the proposed monitoring adequate for detecting impacts on primary producers from a food web perspective? Unrecorded Rocky Reefs Within our submission, the Society provided evidence of reefs located on the shelf area that will be impacted by the plume that were not identified within the TTRL application. This evidence included information from a DOC GIS package of substrate type (Fig 1) and photographic and video evidence obtained by the South Taranaki Underwater Club (see submission). Additional evidence of reefs missed within the TTRL application has been provided by Karen Pratt (submission and non-expert evidence). Fig 1) Habitat and substrate type available from DOC GIS package presented in the NMMRS submission. Note location of reef habitat shown in blue. Within her evidence (page 43 paragraph 103), Alison MacDiarmid states The distribution of rocky reefs in the STB was based on the DOC fairings database and modified according to ground-truthing during other sampling operations, including multibeam acoustic swath mapping carried out by NIWA

3 for TTR. Low-lying reefs may be intermittently smothered by surrounding sediments. The occurrence of small unmapped reefs does not change my conclusion. The Society is concerned about this statement because evidence from the South Taranaki Underwater Club indicates that there are larger reefs (up to four nautical miles long), with high biodiversity values located close to the proposed mining area e.g. the Crack MacDiarmid s statement refers to ground-truthing using multibeam acoustic swath mapping. The Society cannot find the results of the multibeam survey within the current 2016 TTRL application. The Society is aware of a technical report provided as part of the 2013 TTR application titled Multibeam Survey in Southern Taranaki Bight ( However, the report only includes survey results from selected areas within STB (Fig 2) including the instrument mooring area, the FPSO vessel mooring area, tailing dump site and the Dianne and Christina Lip mining areas. The survey results do not cover large areas that are predicted to be impacted by the sediment plume. Fig 2) Areas covered by the Multibeam Survey Report (2013) The Society seeks further clarification about how the distribution of rocky reefs presented in the TTRL application (Fig 3) was determined. If the multibeam survey just covers the areas presented in Fig 2 it is unclear to the Society how this could have been used to ground-truth the area predicted to be impacted by the sediment plume. If the multibeam survey results cover more extensive areas than those presented in Fig 2, the Society does not understand why this information was not presented in the application.

4 Fig 3) Distribution of rocky reefs as presented in the TTRL application (Fig 17 in Anderson et al., 2015, also see Fig 1 in Beaumont et al., 2015). Note that reefs further than 6km offshore are largely missing. In paragraph 91 page 37 of her evidence MacDiarmid states If a consent is granted then the benthic monitoring programme should include hitherto unsampled areas potentially affected by the sediment plume. The Society are of the firm opinion that it is crucial to know this information at the application stage as it is pertinent to the decision of whether the consent should be granted. Rocky Reef Questions To be asked to Alison MacDiarmid (time approx. 10 minutes) Why was additional surveying of inshore reefs undertaken, as presented in Anderson et al., 2015, but no additional surveying of mid-shelf reefs within the area affected by the sediment plume? Is the Society correct in thinking that the results of the multibeam survey were not presented in the 2016 TTRL application? Why was this? What areas have been surveyed by multibeam and how was this information used to ground-truth the distribution of rocky reefs within the Patea Shoals? Based on the answer, is the distribution of rocky reefs presented in the TTRL application accurate and complete? To what extent could reefs present in the area of the sediment plume have been missed? To be asked to Daniel Govier (time approx. 5 minutes) What monitoring is planned to identify the location of reefs present within the area of the sediment plume? Additional missing information In the 2013 TTR application animations of movement of the sediment plume with shifting currents were provided. The Society cannot find these in the 2016 TTRL application.

5 Sediment Plume Animation Questions To be asked to Michael Dearnaley and Mark James (time approx. 2 minutes) Have animations showing predicted movement of the sediment plume been produced? Can these be made publicly available as part of the application?