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Soundscapes are promising indicators of marine habitat condition, yet this approach remains untested in many ecosystems, and soundscape-ecological relationships remain unclear. In this study, we analyzed soundscapes in kelp forest habitats off the coast of California, USA, in Channel Islands National Park. We investigated if (1) soundscape features correlated with ecological variables and (2) these features differed inside and outside of marine protected areas (MPAs). We recorded 1 min every 15 min at 5 sites from 12 May to 23 June 2018. Three sites were in MPAs with high kelp cover and low urchin density, while 2 were in adjacent, unprotected habitats with low kelp cover and high urchin density. To analyze the data, we calculated soundscape features using detection algorithms and acoustic indices, which we then correlated with annual ecological data from 2016 to 2018. We found that drivers of regime shifts in kelp forests, i.e. sea urchin density, kelp cover, and fish diversity, were significantly related to soundscape features. Sea urchin density was positively correlated and kelp cover negatively correlated with the rate of shrimp snaps. Fish species richness and abundance were positively correlated with the intensity and diel dynamics in the low-frequency bands that contained most fish vocalizations. This study demonstrates that marine soundscapes indicate the condition of kelp forests, which are vulnerable to destruction from urchin overgrazing. If marine soundscapes can reliably indicate the status of ecological drivers, then this approach could be a valuable complement to diver surveys in fully assessing marine ecosystem health.

Environmental risk assessment for impact pile driving requires characterization of the radiated sound field. Damped cylindrical spreading (DCS) describes propagation of the acoustic Mach cone generated by striking a pile and predicts sound exposure level (LE) versus range. For known water depth and sediment properties, DCS permits extrapolation from a measurement at a known range. Impact assessment criteria typically involve zero-to-peak sound pressure level (Lp;pk), root-mean-square sound pressure level (Lp;rms), and cumulative sound exposure level (LE;cum). To facilitate predictions using DCS, Lp;pk and Lp;rms were estimated from LE using empirical regressions. Using a wind farm construction scenario in the North Sea, DCS was applied to estimate ranges to recommended thresholds in fishes. For 3500 hammer strikes, the estimated LE;cum impact ranges for mortal and recoverable injury were up to 1.8 and 3.1km, respectively. Applying a 10dB noise abatement measure, these distances reduced to 0.29km for mortal injury and 0.65km for recoverable injury. An underlying detail that produces unstable results is the averaging time for calculating Lp;rms, which by convention is equal to the 90%-energy signal duration. A stable alternative is proposed for this quantity based on the effective signal duration

The acoustical output of marine-seismic airguns is determined from recordings of the sound pressure made on hydrophones suspended below a floating barge from which the airguns are also deployed. The signals from multiple types of airguns are considered and each type is operated over a range of deployment depths and chamber pressures. The acoustical output is characterized in terms of a “source waveform” with dimensions of the pressure-times-distance and in an infinite idealized medium, could be divided by the source-receiver distance to give the sound pressure at that receiver. In more realistic environments, the source waveform may be used to predict the pressure at any arbitrary receiver position simply by the application of a time-domain transfer function describing the propagation between the source and receiver. The sources are further characterized by metrics such as the peak source waveform and energy source level. These metrics are calculated in several frequency bands so that the resulting metrics can be used to characterize the acoustical output of the airguns in terms of their utility for seismic image-processing or possible effects on marine life. These characterizations provide reference data for the calibration of models that predict the airguns' acoustical output. They are validated via comparisons of the acoustic pressure measured on far-field hydrophones and predicted using the source waveforms. Comparisons are also made between empirically derived expressions relating the acoustic metrics to the chamber volume, chamber pressure, and deployment depth and similar expressions from the literature.

The papers in this special issue had its origins in the International Airgun Modeling Workshop (the Workshop), which took place in Dublin, Ireland, on July 16, 2016. The purpose of the Workshop was to address the demand for increasingly precise assessment of the environmental impacts of seismic surveys. However, an increase in precision requires accurate characterization of the sound field radiated by an airgun array, including the interface between source signature models and sound propagation models. The impacts of airgun sounds on marine life are predicted by first deriving the sound field through a combination of source signature models with sound propagation models. Impact ranges are then estimated according to acoustic criteria, and that information can be further analyzed by assessing risks to local densities and populations. The Workshop scope included modeling of the airguns’ signatures and of the sound field at distances from a few meters to a few tens of kilometers from each source, including the near field of a realistic airgun array. In addition to sound pressure, participants were requested to calculate sound particle acceleration because of its importance to fishes and invertebrates.

Regulations for underwater anthropogenic noise are typically formulated in terms of peak sound pressure, root-mean-square sound pressure, and (weighted or unweighted) sound exposure. Sound effect studies on humans and other terrestrial mammals suggest that in addition to these metrics, the impulsiveness of sound (often quantified by its kurtosis β) is also related to the risk of hearing impairment. Kurtosis is often used to distinguish between ambient noise and transients, such as echolocation clicks and dolphin whistles. A lack of standardization of the integration interval leads to ambiguous kurtosis values, especially for transient signals. In the current research, kurtosis is applied to transient signals typical for high-power underwater noise. For integration time (t 2 - t 1), the quantity (t 2 - t 1) / β is shown to be a robust measure of signal duration, closely related to the effective signal duration, τ eff for sounds from airguns, pile driving, and explosions. This research provides practical formulas for kurtosis of impulsive sounds and compares kurtosis between measurements of transient sounds from different sources. © 2020 Acoustical Society of America.

Previous studies exploring injury response to pile driving in fishes presented exposure paradigms (>900 strikes) that emulated circumstances where fish would not leave an area being ensonified. Those studies did not, however, address the question of how many strikes are needed before injuries appear. Thus, the number of strikes paired with a constant single strike sound exposure level (SELss) that can cause injuries is not yet clear. In order to examine this question, hybrid striped bass (white bass Morone chrysops × striped bass Morone saxatilis) were exposed to 8–384 strikes in three different SELss treatments that generated different cumulative sound exposure level values. The treatment with the highest SELss values caused swim bladder injuries in fish exposed to as few as eight pile strikes. These results have important implications for pile driving operations where SELss values meet or exceed the exposure levels used in this study.

Pile driving for the installation of wind farms has become a recent topic of interest as we seek to learn how to protect the marine environment while energy efficient offshore turbines are installed. For environmental compliance, propagation models for spreading from a point source are sometimes used to evaluate impact volumes. Use of a point source is problematic in that a pile (either hammered or shaken using a vibratory source) fully extends through the water column and cannot be considered a point source. In this paper we present a hybrid model solution to evaluate the sound field at close and far ranges. First, a finite element model, consisting of the hammer, pile, the nearby seawater and the sediment, is used to computed the acoustic pressure field at a short range (∼3 m). The sound pressure field versus depth and frequency at this range is used as the starter field for the Parabolic Equation and the field is then propagated to range, including range dependent environments. Impact volumes, for various marine species hearing groups are computed. [Work supported by BOEM.]

Anthropogenic underwater sounds represent a potential risk to aquatic organisms. Many regulators require this risk to be assessed before allowing a sound-producing activity to proceed. Regulators typically set exposure criteria for a range of acoustic parameters and require the assessment to address whether a given acoustic metric would exceed a specified allowable threshold. While the value of the threshold is usually clear, the procedure required to calculate the metric sometimes lacks sufficient detail, leading to uncertainties and potential inconsistencies in interpretation. Procedures are described that enable intra- and inter-project consistency in use, processing, and reporting of metrics. Quantities derived from sound pressure and sound particle motion are considered, providing metrics relevant to assessments for fish, aquatic invertebrates, and aquatic mammals. Specific metrics for which procedures are described include transient duration, zero-to-peak quantities, mean-square and time-integrated-squared quantities (e.g., sound exposure), and their spectral densities. The metrics are relevant to ambient sound and to specified activities such as drilling, pile-driving, seismic imaging, or dynamic positioning. Issues addressed include the specification of fractional octave and fractional decade bands, and the harmonization of units and reference values used for reporting. Continuing efforts on standards for the characterization of underwater sound sources are described.Anthropogenic underwater sounds represent a potential risk to aquatic organisms. Many regulators require this risk to be assessed before allowing a sound-producing activity to proceed. Regulators typically set exposure criteria for a range of acoustic parameters and require the assessment to address whether a given acoustic metric would exceed a specified allowable threshold. While the value of the threshold is usually clear, the procedure required to calculate the metric sometimes lacks sufficient detail, leading to uncertainties and potential inconsistencies in interpretation. Procedures are described that enable intra- and inter-project consistency in use, processing, and reporting of metrics. Quantities derived from sound pressure and sound particle motion are considered, providing metrics relevant to assessments for fish, aquatic invertebrates, and aquatic mammals. Specific metrics for which procedures are described include transient duration, zero-to-peak quantities, mean-square and time-integrated-...

Six species of fishes were tested under aquatic far-field, plane-wave acoustic conditions to answer several key questions regarding the effects of exposure to impulsive pile driving. The issues addressed included which sound levels lead to the onset of barotrauma injuries, how these levels differ between fishes with different types of swim bladders, the recovery from barotrauma injuries, and the potential effects exposure might have on the auditory system. The results demonstrate that the current interim criteria for pile-driving sound exposures are 20 dB or more below the actual sound levels that result in the onset of physiological effects on fishes.

The potential impact of seismic surveys on marine life has given regulators and scientists a shared interest in quantifying the sound field radiated by airgun arrays. Predictions do not always agree well with measurements, and there is a need to build confidence in model accuracy. To address this need, experts in airgun sound field modeling were invited to participate in an international workshop that took place in Dublin on 16 July 2016.The purpose of the Dublin workshop was to improve insight in the characterization of the airgun array sound field, including the interaction between source and propagation models. Well-specified, biologically relevant scenarios were developed, solutions were compared and the differences quantified. Possible causes of these differences were discussed. Qualitative agreement was demonstrated in the time domain source signature. In the frequency domain, inter-model differences exceeded 30 dB above 1 kHz. Differences in initial rise time were identified as the probable cause o...

Pile-driving and other impulsive sound sources have the potential to injure or kill fishes. One mechanism that produces injuries is the rapid motion of the walls of the swim bladder as it repeatedly contacts nearby tissues. To further understand the involvement of the swim bladder in tissue damage, a specially designed wave tube was used to expose three species to pile-driving sounds. Species included lake sturgeon ( Acipenser fulvescens )—with an open (physostomous) swim bladder, Nile tilapia ( Oreochromis niloticus )—with a closed (physoclistous) swim bladder and the hogchoker ( Trinectes maculatus )—a flatfish without a swim bladder. There were no visible injuries in any of the exposed hogchokers, whereas a variety of injuries were observed in the lake sturgeon and Nile tilapia. At the loudest cumulative and single-strike sound exposure levels (SEL cum and SEL ss respectively), the Nile tilapia had the highest total injuries and the most severe injuries per fish. As exposure levels decreased, the number and severity of injuries were more similar between the two species. These results suggest that the presence and type of swim bladder correlated with injury at higher sound levels, while the extent of injury at lower sound levels was similar for both kinds of swim bladders.

Caged fish were exposed to sound from mid-frequency active (MFA) transducers in a 5 × 5 planar array which simulated MFA sounds at received sound pressure levels of 210 dB SPL(re 1 μPa). The exposure sound consisted of a 2 s frequency sweep from 2.8 to 3.8 kHz followed by a 1 s tone at 3.3 kHz. The sound sequence was repeated every 25 s for five repetitions resulting in a cumulative sound exposure level (SEL(cum)) of 220 dB re 1 μPa(2) s. The cumulative exposure level did not affect the hearing sensitivity of rainbow trout, a species whose hearing range is lower than the frequencies in the presented MFA sound. In contrast, one cohort of channel catfish showed a statistically significant temporary threshold shift of 4-6 dB at 2300 Hz, but not at lower tested frequencies, whereas a second cohort showed no change. It is likely that this threshold shift resulted from the frequency spectrum of the MFA sound overlapping with the upper end of the hearing frequency range of the channel catfish. The observed threshold shifts in channel catfish recovered within 24 h. There was no mortality associated with the MFA sound exposure used in this test.

To protect marine life, piling activities at sea are subject to regulations on sound emission. Different regulatory authorities base different action criteria based on different statistics of the emitted sound pressure. Modelling efforts to predict these metrics have achieved mixed success. While the sound exposure level (SEL) can be predicted relatively well, it has proven harder to model the peak sound pressure level (Lpk) accurately. It would therefore be valuable to have a reliable way of estimating Lpk, based on a prediction of SEL. Correlations between SEL and Lpk and between SEL and rms sound pressure level (Lrms) are obtained from measurements during piling of the Luchterduinen wind farm off the Dutch west coast, and are used to assess the applicability of correlations found at other wind farms. A metastudy using data from Luchterduinen as well as the German Bight gives a more robust trend line for use at other North Sea sites. Lrms is computed in two different ways, involving the 90 % energy signal duration on the one hand and the effective signal time duration (Teff) on the other. The value of Lrms based on Teff is found to be more robust. [Work sponsored by BOEM.]To protect marine life, piling activities at sea are subject to regulations on sound emission. Different regulatory authorities base different action criteria based on different statistics of the emitted sound pressure. Modelling efforts to predict these metrics have achieved mixed success. While the sound exposure level (SEL) can be predicted relatively well, it has proven harder to model the peak sound pressure level (Lpk) accurately. It would therefore be valuable to have a reliable way of estimating Lpk, based on a prediction of SEL. Correlations between SEL and Lpk and between SEL and rms sound pressure level (Lrms) are obtained from measurements during piling of the Luchterduinen wind farm off the Dutch west coast, and are used to assess the applicability of correlations found at other wind farms. A metastudy using data from Luchterduinen as well as the German Bight gives a more robust trend line for use at other North Sea sites. Lrms is computed in two different ways, involving the 90 % energy sign...

Fish rely on their auditory system for survival to detect and interpret sounds in their surroundings, especially those originating from predators, prey, and conspecifics. The sensitivity of fish hearing can be impaired, for example, by masking or temporary threshold shifts. To understand and quantify the impact of noise in the oceans, we need a quantitative and comparable understanding of fishes’ impaired and unimpaired hearing sensitivities to sound pressure and sound particle motion. Historically, hearing sensitivities were measured to generate an audiogram for a fish species of interest. Therefore, audiograms are only available for a few individuals representing a few species. Crucially, differences between measurement protocols leave existing audiograms mostly incomparable. The goldfish (Carassius auratus) is a species for which many audiograms have been measured and the reported hearing thresholds exceed a 40 dB spread, largely attributed to differences in methodology rather than in hearing sensitivity [Ladich & Fay, 2013; Maruska & Sisneros, 2016]. These large differences indicate a need to harmonize measurement procedures. Standardization of hearing sensitivity measurements is therefore essential if we are to achieve environmental management goals in the United States, Europe, and worldwide. We propose a path that leads to the development of suitable international standards.

To avoid mortality caused by passage through dam turbines and spillways, juvenile Chinook salmon Oncorhynchus tshawytscha are annually transported downstream by barge through the federal hydropower system on the Snake and Columbia rivers. Survival of transported fish is higher than that of in-river migrants; however, transported fish experience higher rates of postrelease mortality. Increased mortality could result from a decrease in the ability to detect or avoid predators due to stressors associated with the barge environment. This study examined the effects of barging on juvenile Chinook salmon olfaction and auditory function, two sensory systems involved in predator detection. We focused on dissolved metals known to be toxic to the salmon olfactory system and on the level of noise from the barge, which could impair the auditory system. Experimental groups included animals collected (1) before barge loading (control group), (2) at the Bonneville Dam bypass system (migrant fish), (3) immediatel...

This study investigated the effects on rainbow trout (Oncorhynchus mykiss) of exposure to high-intensity, low-frequency sonar using an element of the standard Surveillance Towed Array Sensor System Low Frequency Active (LFA) sonar source array. Effects of the LFA sonar on hearing were tested using auditory brainstem responses. Effects were also examined on inner ear morphology using scanning electron microscopy and on nonauditory tissues using general pathology and histopathology. Animals were exposed to a maximum received rms sound pressure level of 193 dB re 1 microPa(2) for 324 or 648 s, an exposure that is far in excess of any exposure a fish would normally encounter in the wild. The most significant effect was a 20-dB auditory threshold shift at 400 Hz. However, the results varied with different groups of trout, suggesting developmental and/or genetic impacts on how sound exposure affects hearing. There was no fish mortality during or after exposure. Sensory tissue of the inner ears did not show morphological damage even several days post-sound exposure. Similarly, gross- and histopathology observations demonstrated no effects on nonauditory tissues.

Six species of fishes were tested under aquatic far-field, plane-wave acoustic conditions to answer several key questions regarding the effects of exposure to impulsive pile driving. The issues addressed included which sound levels lead to the onset of barotrauma injuries, how these levels differ between fishes with different types of swim bladders, the recovery from barotrauma injuries, and the potential effects exposure might have on the auditory system. The results demonstrate that the current interim criteria for pile-driving sound exposures are 20 dB or more below the actual sound levels that result in the onset of physiological effects on fishes.

Many species of odontocete cetaceans (toothed whales) use high-frequency clicks (60–170 kHz) to identify objects in their environment, including potential prey. Behavioral studies have shown that American shad, Alosa sapidissima, can detect ultrasonic signals similar to those of odontocetes that are potentially their predators. American shad also show strong escape behavior in response to ultrasonic pulses between 70 and 110 kHz and can determine the location of the sound source at least in the horizontal plane. The present study examines physiological aspects of ultrasound detection by American shad and provides the first insights into the neural encoding of ultrasound signals in any nonmammalian vertebrate. The recordings were obtained by penetration through the cerebellar surface. All but two units responded exclusively to ultrasound. Ultrasound-sensitive units did not phase-couple to any stimulus frequency. Some units resembled the response of constant latency neurons found in the ventral nucleus of the lateral lemniscus of bats. We suggest that ultrasonic and sonic signals are processed along different pathways in Alosa. The ultrasonic pathway in Alosa appears to be a feature detector that is likely to be adapted (e.g., frequency, intensity) to odontocete echolocation signals.

Cockroaches ( Periplaneta americana) orient their antennae toward moving objects based on visual cues. Presumably, this allows exploration of novel objects by the antennal flagellum. We used videographic and electrophysiological methods to determine if receptors on the flagellum are essential for triggering escape, or if they enable cockroaches to discriminate threatening from non-threatening objects that are encountered. When a flagellum was removed, and replaced with a plastic fiber, deflection of a "prosthetic flagellum" still activated the descending mechanosensory interneurons associated with escape and produced typical escape responses. However, escape was essentially eliminated by constraining the movement of the scape and pedicel at the antennal base. When cockroaches approached and briefly explored the surface of a spider or another cockroach with the flagellum, they produced escape significantly more often in response to subsequent controlled contact from a spider than from a cockroach. This discrimination did not depend on visual or wind-sensory input, but required flagellar palpation of the surface. The crucial sensory cues appear to involve texture rather than surface chemicals. These results indicate that cockroaches acquire basic information on stimulus identity during exploration of surfaces with flagellar receptors, but that basal receptors are triggers for escape behavior.

The high intensity controlled impedance fluid filled wave tube (HICI-FT) was used to expose fishes, in the laboratory, to impulsive sound signals under controlled conditions. Fish species were exposed to pile driving signals under different experimental paradigms, followed by detailed investigations of their physiological tissue response (aka, barotrauma injuries). Most often the cumulative sound exposure level (SELcum) was held constant while varying the number of pile strikes and the single strike sound exposure level (SELss). Altering these three variables proved the equal energy hypothesis irrelevant; the higher SELss values with fewer number of strikes caused a highest injury levels. The first dose-response curve was generated for fish responses. Comparisons between different species showed fish with no swim bladder at low injury risk, fish with a closed swim bladder (physoclists) at a high injury risk, and fish with an open swim bladder (physostomes) at a moderate injury risk. If fish find safe have...

Anthropogenic underwater sounds can impact aquatic life. Adherence to the Marine Mammal Protection Act (MMPA), the Endangered Species Act (ESA), and the Magnuson-Stevens Fishery Conservation and Management Act (MSA) requires a risk assessment of the potential effects from underwater noise. Procedures for evaluating the risk to marine mammals (MMPA) are increasingly sophisticated, and quantitative science-based criteria for mammals were published in 2007 by Southall et al. The need for equivalent criteria for fishes and sea turtles (ESA and MSA) led to the creation of our expert working group co-led by Professors Arthur Popper and Richard Fay, pillars in the USA for everything fish. While Professor Tony Hawkins, a pillar in the EU for everything fish, brought his own unique perspectives and broad expertise of fish hearing studies and sound exposure. The results from our working group are described from its inception in 2004 to the 2014 publication of its findings as an ANSI/ASA report. The report determine...

Chapters cannot be read stand-alone. Please see complete SpringerBrief at: http://link.springer.com/book/10.1007/978-3-319-06659-2.

Chapters cannot be read stand-alone. Please see complete SpringerBrief at: http://link.springer.com/book/10.1007/978-3-319-06659-2.

Chapters cannot be read stand-alone. Please see complete SpringerBrief at: http://link.springer.com/book/10.1007/978-3-319-06659-2.

Chapters cannot be read stand-alone. Please see complete SpringerBrief at: http://link.springer.com/book/10.1007/978-3-319-06659-2.

Chapters cannot be read stand-alone. Please see complete SpringerBrief at: http://link.springer.com/book/10.1007/978-3-319-06659-2.

Chapters cannot be read stand-alone. Please see complete SpringerBrief at: http://link.springer.com/book/10.1007/978-3-319-06659-2.

(2008). EFFECTS OF EXPOSURE TO PILE-DRIVING SOUNDS ON FISH. Bioacoustics: Vol. 17, No. 1-3, pp. 305-307.

The effects of loud sounds on fishes, such as those produced during impulsive pile driving, are an increasing concern in the management of aquatic ecosystems. However, very little is known about such effects. Accordingly, a High Intensity Controlled Impedance Fluid Filled wave Tube (HICI-FT) was used to investigate the effects of sounds produced by impulsive pile driving on two size groups of hybrid striped bass (white bass Morone chrysops x striped bass Morone saxatilis ). The larger striped bass (mean size 17.2 g) had more severe injuries, as well as more total injuries, than the smaller fish (mean size 1.3 g). However, fish in each size group recovered from most injuries within 10 days of exposure. A comparison with different species from previously published studies show that current results support the observation that fishes with physoclistous swim bladders are more susceptible to injury from impulsive pile driving than are fishes with physostomous swim bladders.

To address growing concern over the impact of anthropogenic sound on fishes, a series of experiments was conducted that exposed several fish species to high-intensity low-frequency naval sonar. This study extends auditory findings by adding largemouth bass, yellow perch, and channel catfish. No effects on hearing were found in largemouth bass and yellow perch and only small effects in channel catfish (a fish with morphological adaptations for enhanced pressure reception). Together with prior findings, these results suggest limited impact on hearing from high-intensity sonar. Susceptibility may be due to genetic stock, developmental conditions, seasonal variation, and/or buoyancy during exposure.

Impulsive pile driving sound can cause injury to fishes, but no studies to date have examined whether such injuries include damage to sensory hair cells in the ear. Possible effects on hair cells were tested using a specially designed wave tube to expose two species, hybrid striped bass (white bass Morone chrysops × striped bass Morone saxatilis) and Mozambique tilapia (Oreochromis mossambicus), to pile driving sounds. Fish were exposed to 960 pile driving strikes at one of three treatment levels: 216, 213, or 210 dB re 1 μPa2·s cumulative Sound Exposure Level. Both hybrid striped bass and tilapia exhibited barotraumas such as swim bladder ruptures, herniations, and hematomas to several organs. Hybrid striped bass exposed to the highest sound level had significant numbers of damaged hair cells, while no damage was found when fish were exposed at lower sound levels. Considerable hair cell damage was found in only one out of 11 tilapia specimens exposed at the highest sound level. Results suggest that impulsive sounds such as from pile driving may have a more significant effect on the swim bladders and surrounding organs than on the inner ears of fishes, at least at the sound exposure levels used in this study.

Potential environmental effects of offshore wind (OSW) energy projects are not well understood, and regulatory agencies are required to make decisions in spite of substantial uncertainty about environmental impacts and their long-term consequences. An understanding of risks associated with interactions between OSW installations and aquatic receptors, including animals, habitats, and ecosystems, can help define key uncertainties and focus regulatory actions and scientific studies on interactions of most concern. To examine the environmental risks associated with OSW developments in the U.S. Pacific Northwest National Laboratory (PNNL) focused on the following four priority research areas in FY 2012: • Environmental Risk Evaluation System (ERES) - Followed project developments on the two OSW projects that PNNL screened in FY 2011 for environmental consequence: Fishermen’s Energy off the coast of Atlantic City, NJ and LEEDCo. near Cleveland, OH in Lake Erie. • Tethys - Developed a smart knowledge base which houses environmental research, data and information pertaining to OSW energy: • Technical Assessment - Produced a new software to create an automated process of identifying and differentiating between flying organism such as birds and bats by using thermal imagery; and • North Atlantic Right Whales - Developed an environmental risk management system to mitigatemore » the impacts on North Atlantic Right Whales (NARW) during installation and piledriving stages of OSW developments. By identifying and addressing the highest priority environmental risks for OSW devices and associated installations the ERES process assists project proponents, regulators, and stakeholders to engage in the most efficient and effective siting and permitting pathways.« less

Progress report on defining and determining monitoring and mitigation measures for protecting North Atlantic Right Whales from the effects of pile driving and other activities associated with installation of offshore wind farms.

Elasmobranch fishes have been around for hundreds of millions of years with very little evolutionary changes, yet our understanding of their hearing abilities is limited to only a few of the hundreds of extant species. Our general understanding suggests a relatively narrow hearing range with relatively poor sensitivity, particularly compared with many teleosts. This lack of knowledge makes it difficult to evaluate the potential effects that could be associated with exposure to anthropogenic noise. However, given the combination of the worldwide increase in anthropogenic aquatic noise as well as the drastic population decline in many species of elasmobranch fishes, it is imperative that noise-exposure studies be conducted to determine whether these fishes are being further threatened by our noise pollution.

There is growing concern that sounds produced by anthropogenic sources have the potential to impact bony fishes. However, there are no data as to whether elasmobranch fishes (sharks, rays, and skates) could be affected by exposure to anthropogenic sources.

Juvenile Chinook salmon, Oncorhynchus tshawytscha, were exposed to simulated high intensity pile driving signals to evaluate their ability to recover from barotrauma injuries. Fish were exposed to one of two cumulative sound exposure levels for 960 pile strikes (217 or 210 dB re 1 µPa(2)·s SEL(cum); single strike sound exposure levels of 187 or 180 dB re 1 µPa(2)⋅s SEL(ss) respectively). This was followed by an immediate assessment of injuries, or assessment 2, 5, or 10 days post-exposure. There were no observed mortalities from the pile driving sound exposure. Fish exposed to 217 dB re 1 µPa(2)·s SEL(cum) displayed evidence of healing from injuries as post-exposure time increased. Fish exposed to 210 dB re 1 µPa(2)·s SEL(cum) sustained minimal injuries that were not significantly different from control fish at days 0, 2, and 10. The exposure to 210 dB re 1 µPa(2)·s SEL(cum) replicated the findings in a previous study that defined this level as the threshold for onset of injury. Furthermore, these data support the hypothesis that one or two Mild injuries resulting from pile driving exposure are unlikely to affect the survival of the exposed animals, at least in a laboratory environment.

Concern continues about the potential effects the sounds produced during pile-driving activities have on fish (e.g., Popper and Hastings 2009). We investigated the effects of high-intensity sound on juvenile Chinook salmon (Oncorhynchus tshawytscha). State-of-the-art equipment was developed to expose fish to pile-driving signals in the laboratory.

Naturally spawning stocks of Chinook salmon (Oncorhynchus tshawytscha) that utilize Puget Sound are listed as threatened (http://www.nwr.noaa.gov/ESA-Salmon-Listings/Salmon-Populations/ Chinook/CKPUG.cfm). Plans exist for prototype tidal turbines to be deployed into their habitat. Noise is known to affect fish in many ways, such as causing a threshold shift in auditory sensitivity or tissue damage. The characteristics of noise, its spectra and level, are important factors that influence the potential for the noise to injure fish. For example, the frequency range of the tidal turbine noise includes the audiogram (frequency range of hearing) of most fish. This study (Effects on Aquatic Organisms, Subtask 2.1.3.2: Acoustics) was performed during FY 2011 to determine if noise generated by a 6-m-diameter open-hydro turbine might affect juvenile Chinook salmon hearing or cause barotrauma. After they were exposed to simulated tidal turbine noise, the hearing of juvenile Chinook salmon was measured and necropsies performed to check for tissue damage. Experimental groups were (1) noise exposed, (2) control (the same handling as treatment fish but without exposure to tidal turbine noise), and (3) baseline (never handled). Preliminary results indicate that low levels of tissue damage may have occurred but that there were no effects of noise exposure on the auditory systems of the test fish.

Snohomish Public Utility District No.1 plans to deploy two 6 meter OpenHydro tidal turbines in Admiralty Inlet in Puget Sound, under a FERC pilot permitting process. Regulators and stakeholders have raised questions about the potential effect of noise from the turbines on marine life. Noise in the aquatic environment is known to be a stressor to many types of aquatic life, including marine mammals, fish and birds. Marine mammals and birds are exceptionally difficult to work with for technical and regulatory reasons. Fish have been used as surrogates for other aquatic organisms as they have similar auditory structures. This project was funded under the FY09 Funding Opportunity Announcement (FOA) to Snohomish PUD, in partnership with the University of Washington - Northwest National Marine Renewable Energy Center, the Sea Mammal Research Unit, and Pacific Northwest National Laboratory. The results of this study will inform the larger research project outcomes. Proposed tidal turbine deployments in coastal waters are likely to propagate noise into nearby waters, potentially causing stress to native organisms. For this set of experiments, juvenile Chinook salmon (Oncorhynchus tshawytscha) were used as the experimental model. Plans exist for prototype tidal turbines to be deployed into their habitat. Noise is known to affect fish in many ways, such as causing a threshold shift in auditory sensitivity or tissue damage. The characteristics of noise, its spectra and level, are important factors that influence the potential for the noise to injure fish. For example, the frequency range of the tidal turbine noise includes the audiogram (frequency range of hearing) of most fish. This study was performed during FY 2011 to determine if noise generated by a 6-m diameter OpenHydro turbine might affect juvenile Chinook salmon hearing or cause barotrauma. Naturally spawning stocks of Chinook salmon that utilize Puget Sound are listed as threatened (http://www.nwr.noaa.gov/ESA-Salmon-Listings/Salmon-Populations/Chinook/CKPUG.cfm); the fish used in this experiment were hatchery raised and their populations are not in danger of depletion. After they were exposed to simulated tidal turbine noise, the hearing of juvenile Chinook salmon was measured and necropsies performed to check for tissue damage. Experimental groups were (1) noise exposed, (2) control (the same handling as treatment fish but without exposure to tidal turbine noise), and (3) baseline (never handled). Experimental results indicate that non-lethal, low levels of tissue damage may have occurred but that there were no effects of noise exposure on the auditory systems of the test fish.

This study investigated immediate effects of intense sound exposure associated with low-frequency (170-320 Hz) or with mid-frequency (2.8-3.8 kHz) sonars on caged rainbow trout Oncorhynchus mykiss, channel catfish Ictalurus punctatus and hybrid sunfish Lepomis sp. in Seneca Lake, New York, U.S.A. This study focused on potential effects on inner ear tissues using scanning electron microscopy and on non-auditory tissues using gross and histopathology. Fishes were exposed to low-frequency sounds for 324 or 628 s with a received peak signal level of 193 dB re 1 microPa (root mean square, rms) or to mid-frequency sounds for 15 s with a received peak signal level of 210 dB re 1 microPa (rms). Although a variety of clinical observations from various tissues and organ systems were described, no exposure-related pathologies were observed. This study represents the first investigation of the effects of high-intensity sonar on fish tissues in vivo. Data from this study indicate that exposure to low and midfrequency sonars, as described in this report, might not have acute effects on fish tissues.

Assessment of fish physiology after exposure to impulsive sound has been limited by quantifying physiological injuries, which range from mortal to recoverable. A complex panel of injuries was reduced to a single metric by a model called the Fish Index of Trauma. Over several years, six species of fishes from different morphological groupings, (e.g., physoclistous, physostomous, and lack of a swim bladder) were studied. The onset of physiological tissue effect was determined across a range of cumulative sound exposure levels with varying number of pile strikes. Follow up studies included investigation of healing from incurred injuries. The level of injury that animals expressed was influenced by their morphological grouping. Finally, investigation of the inner ear sensory hair cells showed that damage occurred at higher sound exposure levels than when the onset of tissue injury would occur.

Reporting accurate metrics while employing good measurement practices is a topic that is gaining awareness. Seemingly a simple and expected task, however when reading current and past literature, reporting sound metrics utilized is often not met. It is clear that increased awareness and development of standardization of acoustic metrics is necessary. When reviewing previously published literature on the effects of sound on fish, it is often difficult to fully understand how metrics were calculated leaving the reader to make assumptions. Furthermore, the lack of standardization and definition decreases the amount of data and research studies that could be directly comparable. In a field that has paucity of effects of sound on fish, this situation underscores the importance and need for standardization.