The underwater environment is filled with biotic and abiotic sounds, many of which can be important for the survival and reproduction of fish. Over the last century, human activities in and near the water have increasingly added artificial sounds to this environment. Very loud sounds of relatively short exposure, such as those produced during pile driving, can harm nearby fish. However, more moderate underwater noises of longer duration, such as those produced by vessels, could potentially impact much larger areas, and involve much larger numbers of fish. Here we call attention to the urgent need to study the role of sound in the lives of fish and to develop a better understanding of the ecological impact of anthropogenic noise.

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A noisy spring: the impact of globally rising underwater sound levels on fish

Global increases in environmental noise levels – arising from expansion of human populations, transportation networks, and resource extraction – have catalysed a recent surge of research into the effects of noise on wildlife. Synthesising a coherent understanding of the biological consequences of noise from this literature is challenging. Taxonomic groups vary in auditory capabilities. A wide range of noise sources and exposure levels occur, and many kinds of biological responses have been observed, ranging from individual behaviours to changes in ecological communities. Also, noise is one of several environmental effects generated by human activities, so researchers must contend with potentially confounding explanations for biological responses. Nonetheless, it is clear that noise presents diverse threats to species and ecosystems and salient patterns are emerging to help inform future natural resource-management decisions. We conducted a systematic and standardised review of the scientific literature published from 1990 to 2013 on the effects of anthropogenic noise on wildlife, including both terrestrial and aquatic studies. Research to date has concentrated predominantly on European and North American species that rely on vocal communication, with approximately two-thirds of the data set focussing on songbirds and marine mammals. The majority of studies documented effects from noise, including altered vocal behaviour to mitigate masking, reduced abundance in noisy habitats, changes in vigilance and foraging behaviour, and impacts on individual fitness and the structure of ecological communities. This literature survey shows that terrestrial wildlife responses begin at noise levels of approximately 40 dBA, and 20% of papers documented impacts below 50 dBA. Our analysis highlights the utility of existing scientific information concerning the effects of anthropogenic noise on wildlife for predicting potential outcomes of noise exposure and implementing meaningful mitigation measures. Future research directions that would support more comprehensive predictions regarding the magnitude and severity of noise impacts include: broadening taxonomic and geographical scope, exploring interacting stressors, conducting larger-scale studies, testing mitigation approaches, standardising reporting of acoustic metrics, and assessing the biological response to noise-source removal or mitigation. The broad volume of existing information concerning the effects of anthropogenic noise on wildlife offers a valuable resource to assist scientists, industry, and natural-resource managers in predicting potential outcomes of noise exposure.

https://www.wildliferesearch.co.uk/Wildlife_Research/Publications_files/A%20synthesis%20of%20two%20decades%20of%20research%20documenting%20the%20effects%20of%20noise%20on%20wildlife%20Shannon.pdf

A synthesis of two decades of research documenting the effects of noise on wildlife

There is increasing concern about the effects of pile driving and other anthropogenic (human-generated) sound on fishes. Although there is a growing body of reports examining this issue, little of the work is found in the peer-reviewed literature. This review critically examines both the peer-reviewed and 'grey' literature, with the goal of determining what is known and not known about effects on fish. A companion piece provides an analysis of the available data and applies it to estimate noise exposure criteria for pile driving and other impulsive sounds. The critical literature review concludes that very little is known about effects of pile driving and other anthropogenic sounds on fishes, and that it is not yet possible to extrapolate from one experiment to other signal parameters of the same sound, to other types of sounds, to other effects, or to other species.

The effects of anthropogenic sources of sound on fishes.

Ocean noise pollution is of special concern for cetaceans, as they are highly dependent on sound as their principal sense. Sound travels very efficiently underwater, so the potential area impacted ...

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The impacts of anthropogenic ocean noise on cetaceans and implications for management

https://homepage.univie.ac.at/friedrich.ladich/Codarin%20et%20al.,%202009.pdf

Effects of ambient and boat noise on hearing and communication in three fish species living in a marine protected area (Miramare, Italy).

Observations of marine fish and invertebrates on an inshore reef were made using TV and acoustic tags one week before, during, and four days after a seismic triple G. airgun (three synchronised airguns, each gun 2.5 l and 2000 psi) was deployed and repeatedly fired. The guns were fired once/min for eight periods on four days at different positions. The structure and intensity of the sound of each triple G. gun explosion was recorded and calibrated. Peak sound pressure levels of 210 dB (rel to 1 μPa) at 16 m range and 195 dB (rel to 1 μPa) at 109 m range were measured at positions where the fish were being observed. The final position of the triple G. gun, at 5.3 m range, had a peak pressure level of 218 dB (rel to 1 μPa). Neither the fish, nor the invertebrates, showed any signs of moving away from the reef. Firing the guns did not interrupt a diurnal rhythm of fish gathering at dusk and passing the TV camera position while the guns were firing. The long-term day-to-night movements of two tagged pollack were slightly changed by the arrival and banging of the guns particularly when positioned within 10 m of their normal living positions. Those reef fish, watched by the TV camera, always showed involuntary reactions in the form of a Mauthner cell reflex, C-start, at each explosion of the guns at all ranges tested (maximum range was 109 m, 195 dB rel to 1 μPa). When the explosion source was not visible to the fish, the C-start reaction was cut short and the fish continued with what they were doing before the stimulus. When the G. gun rack was sunk to the seabed (depth 14 m) visible to the fish and the TV camera, those fish that were observed approaching the G. gun rack when the guns were fired were seen to turn and flee from the very visible explosion. When the gun rack was suspended midwater (5 m depth) and just outside visible range at 16 metres, the fish receiving a 6 ms peak to peak, 206 dB (rel to 1 μPa) pressure swing exhibited a C-start and then continued to swim towards the gun position, their intended swimming track apparently unaltered. The sound of the G. guns had little effect on the day-to-day behaviour of the resident fish and invertebrates.

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Effects of seismic air guns on marine fish

The invention relates to a method of mapping subsurface resistivity contrasts by making multichannel transient electromagnetic (MTEM) measurements on or near the earth's surface using at least one source, receiving means for measuring the system response and at least one receiver for measuring the resultant earth response. All signals from the or each source-receiver pair are processed to recover the corresponding electromagnetic impulse response of the earth and such impulse responses, or any transformation of such impulse responses, are displayed to create a subsurface representation of resistivity contrasts. The invention enables subsurface fluid deposits to be located and identified and the movement of such fluids to be monitored.

Detection of subsurface resistivity contrasts with application to location of fluids

There are three related problems with our approach to signature deconvolution. First, there is a confusion among geophysicists about the basis of the convolutional model itself, which leads to doubts about the value of measurements of the source signature. Secondly, it is not generally recognized that statistical methods of wavelet estimation are unreliable. Thirdly, many explorationists are unaware that it is practical in many cases to make meaningful measurements of the source signature. The convolutional model of the reflection seismogram applies only for a point source, and is the convolution of the source signature with the impulse response of the earth, of Green’s function, which contains all possible arrivals, including reflections, refractions, multiples and diffractions. Stabilized deconvolution of the data with a known band‐limited signature is straightforward. The signature can be obtained by independent measurements, as described in the literature. The recovery of the elastic layer parameters ...

Why don't we measure seismic signatures?

We present results from a transient electromagnetic experiment to detect hydrocarbons and to monitor their movement within a reservoir. The method is illustrated with data obtained from multichannel transient electromagnetic (MTEM) surveys.

Hydrocarbon detection and monitoring with a multicomponent transient electromagnetic (MTEM) survey

We present results of synthetic time-lapse and real repeatability multi-transient electromagnetic
surveys over the North Sea Harding field. Using Archie’s law to convert
porosity and fluid saturation to resistivity we created 3D isotropic models of the reservoir
resistivity at different stages of production from the initial state in 1996 through
to complete hydrocarbon production by 2016 and, for each stage, we simulated an
east-west transient electromagnetic survey line across Harding. Unconstrained 1D
full-waveform Occam inversions of these synthetic data show that Harding should be
detectable and its lateral extent reasonably well-defined. Resistivity changes caused
by hydrocarbon production from initial pre-production state to production of the oil
rim in 2011 are discernible as are significant changes from 2011–2016 during the
modelled gas blowdown phase.
The 2D repeatability surveys of 2007 and 2008 tied two wells: one on and the other
off the structure. Between the two surveys the segment of the field under investigation
produced 3.9 million barrels of oil – not enough to generate an observable time-lapse
electromagnetic anomaly with a signal-to-noise ratio of 40 dB. Processing of the
2007 and 2008 data included deconvolution for the measured source current and
removal of spatially-correlated noise, which increased the signal-to-noise ratio of the
recovered impulse responses by about 20 dB and resulted in a normalized root-meansquare
difference of 3.9% between the data sets. 1D full-waveform Occam inversions
of the real data showed that Harding was detectable and its lateral extent was also
reasonably well-defined.
The results indicate that the multi-transient electromagnetic method is suitable for
exploration, appraisal and monitoring hydrocarbon production.

Antoni Ziolkowski

Papers

Effects of seismic air guns on marine fish

Detection of subsurface resistivity contrasts with application to location of fluids

Why don't we measure seismic signatures?

Hydrocarbon detection and monitoring with a multicomponent transient electromagnetic (MTEM) survey

Multi‐transient electromagnetic repeatability experiment over the North Sea Harding field‡