Oceans of noise - Whale and Dolphin Conservation Society

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5.0 145Tug pulling loaded barge 1.0170Miles et al. 19895.016134m (twin diesel engine) 0.63 159 Malme et al. 1989workboatTanker (135m)Tanker (179m)Supertanker (266m)Supertanker (340m)Supertanker (337m)0.430.060.0080.0070.007169180187190185Containership (219m)Containership (274m)Freighter (135m)0.0330.0080.041181181172Buck and Chalfant 1972;Ross 1976;Thilele and Ødengaard1983Buck and Chalfant 1972;Ross 1976;Thilele and Ødengaard19833.3. Oil and gas exploration3.3.1. Seismic surveysDuring seismic surveys, high intensity, low frequency sounds are directed through the earth'scrust and are reflected at the geological boundaries defining different strata. The reflected soundis processed to provide information about the structure and composition of geological formationsbelow the sea bed and to identify potential hydrocarbon reservoirs (Figure 3.3). During marineseismic surveys, the sound source, usually an array of airguns, is towed at 4-6 knots at a depth of4-10 m (McCauley 1994, Gulland and Walker 1998), and reflected signals are recorded usingarrays of hydrophones several kilometres long. Shots are fired at approximately 6 - 20 secondintervals along pre-determined routes (commonly called “transect” lines or legs). Each transectline can be several hours long, and surveys can last several months and can consist of hundreds oftransects.27
Energy source(Air gun array)Sea surface)Hydrophone array(receivers /detectors)~12mFigure 3.3. The basic components of a marine seismic reflection survey (the layers of the seabedare shaded).3.3.2. Marine seismic surveysMarine seismic surveys are commonly either two-dimensional (2-D) or three-dimensional (3-D),and the type of survey used not only affects the type of data collected but can also affect theextent and duration of exposure to high sound levels.Two-dimensional surveys employ a single airgun array and hydrophone streamer, and areconducted along single lines, or pre-determined tracks within an open grid, to produce a verticalslice or 2-D image through the earth's crust (McCauley 1994; Gulland and Walker 1998). Thesource in this type of survey is often made as strong as possible for maximum penetration(Gulland and Walker 1998). Two-dimensional seismic surveys provide little or no informationabout the true position of reflecting points in the sub-surface (Gulland and Walker 1998) and aretypically used for speculative surveys covering large geographical areas (McCauley 1994).Three-dimensional seismic surveys are characterised by the need to record a grid of data, witheach grid being close enough to allow processing along both grid axes (Gulland and Walker1998), and where each grid point is the centre of a grid cell (usually 25 m by 25 m). Theappropriate processing grids can be used to produce a 3-D reconstruction of the traversed surface,giving a much higher resolution than conventional 2-D surveys. By their nature, 3-D surveysrequire accurate positioning and use multiple parallel hydrophone streamers often in conjunctionwith multiple airgun arrays. Tracklines are often separated by 50 or 100 m (McCauley 1994).Three-dimensional seismic surveys are typically used to define potential and / or existinghydrocarbon deposits and fewer exploration wells are needed as a result. However, there are nowmoves to use 3-D surveys for speculative exploration, with the extra cost being balanced by thequality and quantity of data produced (McBarnet 1993 in McCauley 1994).28
Page 2: Oceans of Noise 2004A WDCS Science
Page 8 and 9: In the US, the deployment of Low Fr
Page 10 and 11: its propagation beyond those declar
Page 12 and 13: The best evidence for noise being f
Page 14 and 15: Box 1. Characteristics of sound / l
Page 16 and 17: Sound speed (c)The speed (c) of a w
Page 18 and 19: Box 2. The effects of temperature,
Page 20 and 21: 2.1.2. Measuring sound intensityIde
Page 22 and 23: i.e. Equal pressure measurements di
Page 24 and 25: Spherical or Geometrical spreading
Page 30 and 31: The source used during 3-D surveys
Page 32 and 33: Machinery noisePropulsion machinery
Page 34 and 35: Man-made islands /caissonsFixed pla
Page 36 and 37: 12 3245Drill bit6Figure 3.4. Sound
Page 38 and 39: Transientnoise sourcesAircraftHelic
Page 40 and 41: Results from the aerial surveys con
Page 42 and 43: haemorrhaging in the inner ears and
Page 44 and 45: However they also noted that whales
Page 46 and 47: 4. The Use of Sound by CetaceansChr
Page 48 and 49: seems logical, therefore, that if t
Page 50 and 51: However, despite the reported low a
Page 52 and 53: Kamminga and Wiersma 1981;Akamatsu
Page 54 and 55: SongSocial callsShrieksSlaps0.03-80
Page 56 and 57: anthropogenic factors that make the
Page 58 and 59: 5.3 Longer-term impactsNoise is cle
Page 60 and 61: 5.4 Indirect impactsThe above impac
Page 62 and 63: decompression sickness (DCS) as see
Page 64 and 65: 6. Examples of regional and nationa
Page 66 and 67: 6.3 ASCOBANS and ACCOBAMSTwo region
Page 68 and 69: implications and the discussion sho
Page 70 and 71: 7.1. Consideration of Voluntary vs.
Page 72 and 73: acoustic measurements have been mad
Page 74 and 75: 7.6. Methods of protectionComplianc
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7.6.1 Monitoring7.6.1.1 Visual, aco
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Delory et al. (2002) use Ambient No
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8. ReferencesAburto, A., Rountry, D
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Caldwell, M.C., Caldwell, D.K., and
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Engas, A., Lokkeborg, S., Ona, E. a
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IWC 2002b. Report of the Scientific
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McCauley, R.D. 1994. Seismic Survey
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Potter, J. and Delory, E. 2001. Noi
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Smolker, R.A., Mann, J. and Smuts,
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Watkins, W.A. 1981b. The activities
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ANNEX 1The Application of Marine Po
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an important factor. 13 The judgeme
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in the preparatory work of the LOSC
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practice by the UNEP Governing Coun
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protection and preservation of the
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than international rules, standards
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Four of the twelve regional seas tr
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seismic operations in the Protocol
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ConclusionAt the global level, only
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Art 209 LOSC focuses on both standa
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No State Party may impose condition
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coastal States”. This formulation
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If the IMO makes this determination
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estrictions to vessels operating in
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In the EEZ, in comparison to the te
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Appendix A - Some international ins
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Convention for the Protection of th
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Available at:http://www.unep.ch/sea
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BucharestConventionArticle XIPollut
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environment1. The Contracting Parti
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- that under Article III.8.c) of AC
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e) no sudden or repeated change in
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Ref: Nowacek et al. 2001.Location:
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Location: Arctic• Vocal behaviour
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• Vaquita surfacing duration and
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• 6% of small delphinids (n=264;
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Species type: Boto, Inia geoffrensi
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• Humpback whales appeared tolera
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• Behaviour interpreted as aggres
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• There was no evidence of minke
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• Northern right whales may be ap
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• Migrating gray whales disturbed
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to Ensenada De La Paz, Mexico. Aqua
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distribution of humpback whales, Me
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Richardson, C.R. Greene, C.I. Malme
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Zhou, K., Pilleri, G. and Li, Y. 19
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6. surveys for Cuvier’s beaked wh
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