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EnviroGulf Consulting |
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INDEPENDENT ENVIRONMENTAL CONSULTANCY | ||
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ABN 62 713 622 437 |
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SITE MENU |
Underwater Noise Impact Assessment |
Underwater Noise Impact Assessment
EnviroGulf Consulting undertakes screening underwater noise impact assessments for Environmental Impact Statements (EISs) or equivalent documentation, and assists clients to achieve compliance with licencing conditions relating to underwater noise.
Approach
EnviroGulf Consulting undertakes an initial desktop study with the following elements that form part of a comprehensive scoping process and which are required to assess underwater noise impacts:
Baseline characterisation
Based on literaure reviews, baseline characterisation of the abiotic and biotic environment of the study area in which a proposed noise-generating activity may be proposed is required.
- Baseline oceanographic conditions that may affect sound
transmission:
- water depth (e.g., shallow or deep water).
- proximity to coast (upslope effects).
- proximity to deep water (downslope effects).
- water temperature.
- seawater density
- substrate type (e.g., sand, gravel, bedrock, etc.).
- Baseline marine fauna distribution:
- Spatial and temporal distribution of key marine fauna observed or likely to be present in the study area.
- Species of conservation value.
- Cetacean calving, resting or nursery habitats.
- Cetacean migratory pathways.
- Little Penguin and Australian fur seal rookeries and haulouts.
- Spatial and temporal abundance of selected noise-sensitive marine fauna in the study area.
- Presence of marine protected ares or coastal faunal reserves in or near study area.
- Assess Matters of National Environmental Significance (MNES) under the Commonwealth Environment Protection and Biodiversity Conservation Act, 1999 (the EPBC Act).
Ambient/background noise levels
Investigate the existing underwater noise environment of the study area based on literature review and relevant site-specific conditions.
- Identify the main components of ambient background noise:
- Natural physical sources such as wind, sea state, earthquakes or tremors, rainfall, etc.
- Natural biological sources such as cetacean echolation and communication calls; snapping shrimp, soniferous fish, stridulation, etc.
- Existing anthropogenic sources such as shipping, coastal construction (e.g., pile driving, seismic surveys, seal scarers, etc.
Sensitivity of marine fauna to underwater noise
Identify noise-sensitive key fauna in study area and characterise their hearing range and frequencies
- Literature reviews of marine fauna hearing range and
frequencies:
- Hearing frequency range
- Audiograms.
- Laboratory based physiological hearing range from experiments.
Characterise noise source levels:
Obtain underwater noise signatures of equipment or vessels involved in marine construction or operations or undertake a literature review of similar noise-generating activities or equipment used.
- Literature reviews:
- Characterise similar noise-generating activities or equipment (e.g., dredging, trenching, rock breaking, pile driving, seismic survey, etc.).
- Identify types of noise generated such as impulsive noise or non-impulsive noise.
- Characterise frequency range of noise emissions.
- Characterise duration of noise emissions (e.g., instantaneous (explosions), continuous, intermittent, transient, etc.).
Underwater noise propagation and tranmission loss
Undertake underwater noise modelling of sound propagation and transmission loss between the underwater noise sources and the receptors (i.e., noise-sensitive marine fauna) to predict received noise levels at different distances from the noise source(s).
- Calculate noise transmission loss:
- Depending on water depth, calculate transmission loss using geometric spreading equations (e.g., spherical, cylindrical or practical spreading models).
- Determine distance to isopleths of interest including threshold exposure criteria for different noise-sensitive marine fauna.
- Plot isopleth maps for study area.
Define marine fauna impact exposure criteria
Review relevant noise impact assessment criteria and define marine fauna impact exposure criteria applicable to the study area.
- Literature reviews:
- Marine fauna exposure criteria for acoustic damage (e.g., tissue or auditory damage, Permanent Threshold Shift (PTS), etc.).
- Marine fauna exposure criteria for acoustic disturbance (e.g., behaviuoral response, attraction to or movement away from noise sources, etc.).
- Marine fauna exposure criteria for physiological (auditory) effects (e.g., Temporary Threshold Shift (TTS)).
Noise mitigation and management measures
Prior to assessing impacts on noise-sensitive marine fauna, review mitigation and management measures that may be applied to reduce underwater noise source levels or propagation.
- Mitigation measures:
- Avoidance of noise-producing activities during peak periods of marine fauna aggregation or migration.
- Use of bubble curtains or other enclosures fitted around piles being driven.
- Use of noise reduction, impact-resistant cushions on top of piles being driven.
- Application of non-impulsive vibratory pile driving in lieu of pile-driving hammers, where seabed ground conditions allow.
- Noise reduction management measures:
- Reduction of louder noise sources when marine mammals approach within 1-km buffer ("safety") zone around a marine construction or operational activity (e.g., vessels reduce speed or stop and idle).
- Temporary cessation of construction actvities or operations when noise-sensitive fauna are observed in 1-km buffer zone.
Assess underwater noise impacts to marina fauna
Assess residual impacts of activity-generated noise on marine fauna after mitigation and managemnet measures have been applied.
- Assess underwater noise residual impacts by severity on marine fauna:
- Acoustic damage impacts to marine fauna.
- Acoustic disturbance to marine fauna.
- Acoustic-induced physiological (auditory) impacts on marine fauna.
The Need for Numerical Modelling
Where the above screening level analysis of underwater noise indicates significant residual impacts on noise-sensitive marine fauna, further more detailed and sophisticated numerical modelling may be required. In this case, EnviroGulf Consulting recommends that an acoustical specialist familiar with the latest numerical and computaional methods be consulted.
EnviroGulf Consulting can recommend to clients suitable acoustic consultants who have access to public modelling software or who have developed their own proprietary computer modelling software.
Experience
EnviroGulf Consulting experience in underwater noise impact assessments is summarised below:
- Deep Ocean Polymetallic Nodule Mining Project (2022) - Preparation of a preliminary underwater noise and vibration impact assessment for the NORI-D Contract Area Draft Environmental Impact Satement. Clarion-Clipperton Zone (CCZ), Central Pacific Ocean (to The Metals Company Limited).
- Western Storm Bay Aquaculture Project (2018) - Underwater Noise Impact Assessment in Relation to Southern Right Whales. Assessment of underwater noise generated by salmon farm construction and operations and consequential acoustic damage, acoustic disturbance and physiological (auditory) impacts to Southern Right Whales (Eubalaena australis) after mitigation and management measures have been applied (to Huon Aquaculture Pty Ltd).
- West-of-Wedge Island Aquaculture Project (2018) - Underwater Noise Impact Assessment in Relation to Southern Right Whales. Assessment of underwater noise generated by salmon farm construction and operations and consequential acoustic damage, acoustic disturbance and physiological (auditory) impacts to Southern Right Whales (Eubalaena australis) after mitigation and management measures have been applied (with CBM Sustainable Design Pty Ltd for Tassal Operations Pty Ltd).
- Storm Bay North Aquaculture Project (2018) - Underwater Noise Impact Assessment in Relation to Southern Right Whales. Assessment of underwater noise generated by salmon farm construction and operations and consequential acoustic damage, acosutic disturbance and physiological (auditory) impacts to Southern Right Whales (Eubalaena australis) after mitigation and management measures have been applied (with CBM Sustainable Design Pty Ltd for Petuna Aquaculture Pty Ltd.
- Storm Bay Aquaculture Projects (2018) - Cumulative Underwater Noise Impact Assessment of Storm Bay Marine Farms in Relation to Southern Right Whales. Assessment fo cumulative noise impacts from the construction and operation of three proposed salmon farms to migratory Southern Right Whales (Eubalaena australis) in Storm Bay, southeast Tasmania (with CBM Sustainable Design Pty Ltd for Huon Aquaculture Company Pty Ltd, Petuna Pty Ltd and Tassal Operations Pty Ltd).
- ArgoNautica Toll Ports Project: Berthing and Infrastructure (2018) - Underwater Noise Impact Assessment Study. Underwater noise assessment of the impacts of backhoe dredging, pile driving, drilling, hydrohammering, dredged material barges and tugs on marine life for upgrade of McGaw Wharf Berth No. 4, Port of Burnie. Report TR186 (to ERIAS Group Pty Ltd for Toll).
- ArgoNautica Toll Ports Project: Berthing and Infrastructure (2018) - Underwater noise impact assessment study of backhoe dredging, onshore pile driving, drilling, concrete scour removal, dredged material barges and tugs for upgrade of Webb Dock East Berth No. 1, Port of Melbourne. Report No. TR 187 (to ERIAS Group Pty Ltd for Argonatutica Toll).
- Western Pacific Ocean Project (2018) - Confidential underwater noise and vibration modelling and impact assessment. Report TR184/2/v1. Prepared by EnviroGulf Consulting for Newcrest Mining Limited.
- Papua LNG Project (2017) - Underwater Noise Baseline Characterisation. Desktop study to characteise background ambient background noise (soundscapes) noise in the Purari and Pie river estuaries and Gulf of Papua nearshore and offshore areas, including major shipping channles and coastal shipping routes. Report TR167/2 (to ERIAS Grooup Pty Ltd for TOTAL E&P PNG Limited).
- Pasca A Development Project (2015 - 2016) - Integrated impact assessment of drill cutting disposal (five wells), wastewater discharges and underwater noise from an offshore gas processing platform with storage and offloading (FSO) vessels for condensate and liquefied petroleum gas (LPG) and gas reinjection on the local offshore sedimentology, water quality and marine biological environment in the Gulf of Papua (with ERIAS Group Pty for Twinza Oil Limited).
- Solwara 1 Project (2016) - Underwater noise and vibration assessment and predicted acoustic damage and disturbance impacts on whales, dolphins, fish and sea snakes from a Seafloor Massive Sulphide (SMS) mining operation (to Nautilus Minerals, Inc.).
- Bell Bay Pulp Mill Project (2007) - Residual Impacts of Wharf Facility Construction and Operations. Desktop study of underwater noise generated by wharf contruction, pile driving and construction vessel traffic on noise sensitive fauna of the Tamar Estuary and migratory fish. In: Appendix 3 of Witness Statement of Mr. David Balloch, EnviroGulf Consulting (to Gunns Lmited).
- Bell Bay Pulp Mill Project (2007) - Residual Impacts of Marine Construction. Assessment of underwater noise generated by outfall pipeline shore crossing, intertidal and subtidal hydraulic backhoe trench excavation and radiated underwater noise from marine construction vessels and residual impacts on noise-sensitive marine fauna of southern Bass Strait. In: Appendix 5 of Witness Statement of Mr. David Balloch, EnviroGulf Consulting (to Gunns Limited).
- Offshore Seismic Program (2003) - Technical review, edit and contributions to Seafood Industry Victoria report on "Potential Effects of Seismic Noise on Southern Rock Lobster Larvae" from underwater noise generated by proposed offshore seismic surveys along the southwest coast of Victoria, Australia (to Santos Limited).
- Otway Drilling Project (2003) - Assessment of the effects of underwater noise from proposed offshore drilling and associated supply vessels and helicopters on cetaceans along the Bonney Coast upwelling off Victoria, Australia (to Santos Limited).
