The Environmental Agency for the Mineral Resources Area (EAMRA) Jesper Bistrup Larsen. RE: TGS-NOPEC s EIA for the SEG15 seismic survey

Transcription

1 DCE DANISH CENTRE FOR ENVIRONMENT AND ENERGY AARHUS UNIVERSITY PINNGORTITALERIFFIK Greenland Institute of Natural Resources The Environmental Agency for the Mineral Resources Area (EAMRA) Jesper Bistrup Larsen RE: TGS-NOPEC s EIA for the SEG15 seismic survey Conclusions DCE and GINR acknowledge that the following initiatives contribute to reduce environmental impacts: A slightly smaller airgun volume is applied in 2015 compared to previous years. The streamer is solid. Additional mitigation measures regarding bowhead whales. David Boertmann Line Hermansen Josephine Nymand Date: 17. april 2015 Page 1/6 DCE and GINR miss: An impact assessment of the use of multibeam echo sounder and sub bottom profiling equipment. DCE and GINR require that: Noise measurements are performed both on the NEG15 and the SEG15 surveys. DCE and GINR draw attention to: That the results of the 2015 noise measurements shall be submitted to EAMRA within two months after the completion of the survey. That the use of the large airgun array (5,025 in 3 ) shall be reported. DCE and GINR do not agree on the evaluation of: Impacts of oil spills on some of the bird populations. The importance classification on some of the bird populations. The degree of disturbance classification of narwhal; it is too low, resulting in a too low assessment of sensitivity to noise. DCE and GINR evaluate that - except for the exceptions mentioned above: Generally the assessment of impacts is sound. Introduction TGS plans to undertake a 2D-seismic survey in the waters off Southeast Greenland in summer/autumn The survey period is indicated as 5 July to 31 October. The survey is a part of a wider survey in East Greenland waters with the same vessels, and it is likely that only a part of the programme will be completed. DCE Aarhus University Frederiksborgvej 399 P.O. Boks Roskilde, Denmark PINNGORTITALERIFFIK Greenland Institute of Natural Resources Kivioq 2 P.O. Boks NUUK

2 Side2/6 TGS applied for similar surveys in 2011, 2012, 2013 and 2014, but have so far, only shot only very few lines, and the 2013 and 2014 surveys were actually given up. The application covers a maximum of 1000 line km. The survey will take place between approx. 64 and 66 N, where the lines are placed in a coarse network spaced with down to 15 km. The closest distance to the coast will be approx. 30 km. The sound source is intended to be an airgun array with a total volume of 3,350 in 3, however a larger volume (5,025 in 3 ) may also be used. The first mentioned airgun volume is slightly smaller than the volume previously used or intended to be used (3,680 in 3 ). This is acknowledged, as it may contribute to reduce the environmental impacts. A single solid streamer, up to 8 km long, will be deployed. Besides the seismic acquisition it is planned to use multibeam echo sounder and sub-bottom profiling equipment to acquire information on the seabed. Besides the acquisition vessel, a support vessel will participate in the seismic survey. The Ice Class M/V Akademik Shatskiy is proposed as the main acquisition vessel with M/V Kvitbjørn as support vessel. Based on the scoping document, DCE and GINR evaluated (8 Dec. 2014) that a proper Environmental Impact assessment (EIA) of the survey should be carried out. TGS-NOPEC has only submitted one document for this EIA-evaluation - the EIA report. The requested datasheets were submitted with the scoping documents in December The requested modelling of underwater sound propagation is the same as in 2013 and 2014 and there is referred to the report submitted in The EIA Maritime operations The maritime operations will according to the EIA follow the general environmental shipping regulations by MARPOL, OSPAR and IMO regarding waste handling, discharges and use of chemicals. These regulations are followed during other maritime activities, such as scientific surveys and fishery in the Greenland waters, and as the SEG15 survey do not differ from such shipping, DCE and GINR have no further comments to these issues.

3 Side3/6 Regarding emissions to air, the ships will use low sulphur (< 1.5%) marine gas oil (MGO) for the engines, which is a more environmental sustainable alternative than heavy fuel oil (HFO). The environmental descriptions The descriptions of physical and biological environments are in agreement with the guidelines. Compared to the 2013 and 2014 (version 1) editions of the EIA, the 2014 edition begins to understand the difference between Arctic cod and Atlantic cod. However, there are still some misunderstandings. Atlantic cod is not an important part of the food chain in the Greenland Sea (p. 29). Polar cod is. The section on fishing should also include Atlantic mackerel, which seems to be a promising new resource in the area. The proposed seismic lines overlap slightly with the areas of concern for narwhals. Both the proposed June-September area and the October- November area. The survey is 2D with widely separated lines and performed by one ship, why there is no reason for special regulation. The assessment The assessment is nearly identical to the assessment of the SEG14 survey. This means that some of DCE and GINR s comments from 2014 are still valid. For example the Tables 7-2 and 7-3 are not obvious. It is not really clear what kind of interests the Factor-column refers to in Table 7-2. Or why low likelihood of occurrence can only cause moderate impacts in Tables 7-3 to 7-5? Also, impact tables should point out that the assessed impacts are based on the appropriate mitigation measures (Section 9) being followed. The assessment of oil spill impacts on seabirds has been improved since the first version of SEG14. Both little auk and thick-billed murre are included in the SEG15 version, but the reason for little auk is of national importance in relation to disturbance by ships and of international importance when impacted by oil spills is not explained. In fact, both little auk and thick-billed murre are of international importance, because the survey area is a migration corridor for millions thick-billed murres and little auks breeding in Svalbard and Arctic Russia.

4 Side4/6 In Table 7-13 on assessment of impacts from seismic survey on marine mammals, some assessments are also disputed by DCE and GINR. In the section Disturbance/displacement by underwater noise, narwhal is given medium as Degree of disturbance. Narwhals are considered as very sensitive to noise, why this certainly should be high. This results in an assessment as minor in the Magnitude of impact-column, which obviously is too low. A section on cumulative impacts is new for the SEG EIA-reports. Here it would be relevant to include other activities in the area, e.g. fishery. Despite the objections, the resulting assessment of impacts of the planned activities is generally sound. However, the use of multibeam echo sounder and sub-bottom profiling equipment is not evaluated, and this should be done before the report is evaluated by Naalakkersuisut. The sound modelling The sound propagation model presented for the SEG15 survey is identical to the model presented for the SEG14 survey, and it is supplemented with models of summed energy for all pulses for 24 hours, indicating the distance to SEL (Sound Exposure Level) thresholds for pinnipeds and cetaceans. Both reports (2014 and 2015) state that..even for higher frequencies it is expected that seismic noise will remain above 150 db re 1µPa peak-peak for some tens of kilometers. However, this is not used further in the sound modelling, and on the contrary to this, both reports state that Noise modelling stopped at 1 khz since a test case demonstrated rapid attenuation of higher frequencies. It is unclear which test case they are referring to, and whether this test case was actually conducted in the relevant area (for 2014 and 2015 surveys) or based on a test case conducted elsewhere. In recent years, the suitability of M-weighted SELs for impact assessments, in particular for mid- to high frequency species (e.g. narwhals and porpoises), has been questioned, and there is increasing evidence that higher frequencies should be weighted higher. In general, the sound modelling is adequate, considering that much of the environmental input is based on assumptions. However, to improve the model results in the future, DCE and GINR will underline that actual noise measurements should be conducted during the surveys, including determination of sound speed profiles, (cf. section 6.3. in the EIA-guidelines).

5 Side5/6 These measurements should be used for validation of the model, in particular to verify the assumption that sounds above 1 khz does not propagate out to considerable ranges. Furthermore, actual measurements can optimize the model, so that mitigation measures can be better fitted to actual exposure levels. Thereby TGS will minimize unnecessary mitigation measures, in comparison to when impact assessments are based on worst case assumptions. MMSO s In total, four MMSO s are planned to participate in the survey and two of these will be PAM-operators. This is in accordance with new stipulations. DCA and GINR will underline the importance of following the standardized seabird and marine mammal survey. MMSO s shall follow the Manual for seabird and marine mammal survey on seismic vessels in Greenland (Link) and it is necessary to stress that it is the responsibility of the operator that an observation box for the MMSO s are in place on top of the bridge ( monkey island ). The guidelines have been up-dated on the MMSO issue, and this section can be downloaded from the MLSA-website (Link). An updated version (4 th edition) of the entire manual will be available before the survey is initiated. Mitigation and monitoring The chapter on mitigation and monitoring (8) follows the DCE-guidelines closely. DCE and GINR acknowledge that TGS-NOPEC has introduced (as in 2013 and 2014) additional mitigation measures regarding bowhead whales (Sections 7.3/9.2). According to the EIA-guidelines (section 6.3) the actual sound exposure within the area where sound propagation has been modelled, shall be documented. Such measurements are described in section 9.2. It is stated that these measurements will take place in both the NEG15 and the SEG15 survey areas if possible. DCE and GINR find it very important that measurements are taken in both areas. Noise measurements As a part of the monitoring TGS-Nopec is requested to undertake measurements of the noise propagation during the seismic survey. Section 9.2 describes the proposed noise monitoring efforts. DCE and GINR agree with the suggested monitoring at ranges between 500 m and 5 km from the

6 Side6/6 survey vessel, and at different depths to estimate both the horizontal and vertical propagation of sound. DCE and GINR emphasize the importance (as also suggested in section 9.2) to record broadband seismic pulses and the suggested limits of the recording system within the range 7 Hz (or 10 Hz depending on water depths) and 80 khz can be supported. This allows for evaluation also of the propagation of sound at frequencies above 1 khz, which is highly relevant in assessments of impacts on mid- to high-frequency whale species (e.g. narwhals and porpoises). TGS-Nopec may consider conducting noise measurements with stationary sound recorders instead of deploying hydrophones from the supply vessel. A sound recording chain with recorders at different depths can be deployed on a bouy to get actual exposure levels in relevant areas, such as the border to the closed area for narwhals. Such a set-up can record continuously until equipment is retrieved. In this case it also is important to determine sound speed profiles for the area, which could be done during deployment and retrieval of recording gear. As there is a risk of loss of equipment, it would be wise to deploy 2 or 3 recording chains. A description of such a set-up can be found in this report: Miscellaneous It is mentioned that a larger airgun volume (5,025 in 3 ) may be applied. If this is the case, this shall be reported (start and stop of the use) at the end of the survey. The results of the noise measurements shall be submitted to EAMRA and its scientific advisors within two months after the completion of the seismic survey.