1aABa1 – Ending the day with a song: patterns of calling behavior in a species of rockfish

Annebelle Kok – akok@ucsd.edu
Ella Kim – ebkim@ucsd.edu
Simone Baumann-Pickering – sbaumann@ucsd.edu
Scripps Institution of Oceanography – University of California San Diego
9500 Gilman Drive
La Jolla, CA 92093

Kelly Bishop – kellybishop@ucsb.edu
University of California Santa Barbara
Santa Barbara, CA 93106

Tetyana Margolina – tmargoli@nps.edu
John Joseph – jejoseph@nps.edu
Naval Postgraduate School
1 University Circle
Monterey, CA 93943

Lindsey Peavey Reeves – lindsey.peavey@noaa.gov
NOAA Office of National Marine Sanctuaries
1305 East-West Highway, 11th Floor
Silver Spring, MD 20910

Leila Hatch – leila.hatch@noaa.gov
NOAA Stellwagen Bank National Marine Santuary
175 Edward Foster Road
Scituate, MA 02474

Popular version of paper 1aABa1 Ending the day with a song: Patterns of calling behavior in a species of rockfish
Presented Tuesday morning, June 8, 2021
180th ASA Meeting, Acoustics in Focus

Fish can be seen as ‘birds’ of the sea. Like birds, they sing during the mating season to attract potential partners to and to repel rival singers. At the height of the mating season, fish singing can become so prominent that it is a dominant feature of the acoustic landscape, or soundscape, of the ocean. Even though this phenomenon is widespread in fish species, not much is known about fish calling behavior, a stark contrast to what we’ve learned about bird calling behavior. As part of SanctSound, a large collaboration of over 20 organizations investigating soundscapes of US National Marine Sanctuaries, we have investigated the calling behavior of bocaccio (Sebastes paucispinis), a species of rockfish residing along the west coast of North America. Bocaccio produce helicopter-like drumming sounds that increase in amplitude.

We deployed acoustic recorders at five sites across the Channel Islands National Marine Sanctuary for about a year to record bocaccio, and used an automated detection algorithm to extract their calls from the data. Next, we investigated how their calling behavior varied with time of day, moon phase and season. Bocaccio predominantly called at night, with peaks at sunset and sunrise. Shallow sites had a peak early in the night, while the peak at deeper sites was more towards the end of the night, suggesting that bocaccio might move up and down in the water column over the course of the night. Bocaccio avoided calling during full moon, preferentially producing their calls when there was little lunar illumination. Nevertheless, bocaccio were never truly quiet: they called throughout the year, with peaks in winter and early spring.

The southern population of bocaccio on the US west coast was considered overfished by commercial and recreational fisheries prior to 2017, and has been rebuilt to be a sustainably fished stock today. One of the keys to this sustainability is reproductive success: bocaccio are very long-lived fish that don’t reproduce until they are 4-7 years old, and they can live to be 50 years old. They are known to spawn in the Channel Islands National Marine Sanctuary region from October to July, peaking in January, and studying their calling patterns can help us ensure that we keep this population and its habitat viable well into the future. Characterizing their acoustic ecology can tell us more about where in the sanctuary they reside and spawn, and understanding their reproductive calling behavior can help tell us which time of the year they are most vulnerable to noise pollution. More importantly, these results give us more insight into the wondrous marine soundscape and let us imagine what life must be like for marine creatures that contribute to and rely on it.

3aAB2 – Assembling an acoustic catalogue for different dolphin species in the Colombian Pacific coast: an opportunity to parameterize whistles before rising noise pollution levels.

Daniel Noreña – d.norena@uniandes.edu.co
Kerri D. Seger
Susana Caballero

Laboratorio de Ecologia Molecular de Vertebrados Marinos
Universidad de los Andes
Bogotá, Colombia

Popular version of paper 3aAB2
Presented Wednesday morning, December 9 , 2020
179th ASA Meeting, Acoustics Virtually Everywhere

Growing ship traffic worldwide has led to a relatively recent increase in underwater noise, raising concerns about effects on marine mammal communication. Many populations of several dolphin species inhabit the eastern Pacific Ocean, particularly along the Chocó coast of Colombia. Recent research has confirmed that anthropologic noise pollution levels in this region are one of the lowest in any studied area around the globe, allowing an opportunity for scientists to listen and analyze a relatively undisturbed soundscape in our oceans.

Figure 1. Vessel traffic in the Americas (a) and in (b) Colombia in particular. Red indicates high traffic and blue areas have no traffic. Note the gap in traffic in the Colombian Pacific coast where the Gulf of Tribugá is located (inside black/red box) as compared to all other coastal regions.

Currently, the CPC is slated for the construction of a port in the Gulf of Tribugá, pending permits. Previous port construction projects in other countries have shown that this will change the acoustic environment and could compromise marine fauna, such as dolphin communication. This is the first study to document the whistle acoustic parameters from several dolphin species in the region before any disturbance. Opportunistic recordings were made in two different locations alongside the coast: Coquí, Chocó, and a few hundred kilometers north Bahía Solano, Chocó.

Figure 1. (a) The Colombian Pacific coast and (b) whale-watching locations and ports of the Pacific coast of Colombia. Ports are red markers and whale-watching spots are blue markers.

Five different delphinid species were recorded: Common bottlenose dolphin (Tursiops truncatus), Pantropical spotted dolphin (Stenella attenuata), Spinner dolphin (Stenella longirostris), False killer whale (Pseudorca crassidens) and Short- beaked common dolphin (Delphinus delphis). Comparing these recordings to those made from dolphin populations in more disturbed areas around the globe showed that the repertoires of four of the five species were different. These differences could be because the Chocó dolphins represent populations that use whistles with more natural features while the other, more disturbed, populations may have already changed their whistle features to avoid overlapping with boat traffic noise.

However, avoiding overlap with other conspecifics or other species in the same habitat is natural, too. This is called the acoustic niche hypothesis (ANH). The ANH states that geographically sympatric species should occupy specific frequency bands to avoid overlapping with each other. A Linear Discriminant Analysis (LDA) was done to explore whether the five different species have already adjusted their whistle features to avoid overlapping with other species. Frequency band separation is not the only feature of whistles that dolphins could adjust. The LDA used nine different features to observe if there is any natural division between any of the features.

dolphinFigure 2. LDA plot for nine whistle variables among the five species.

Tracking these whistle features in Chocó over time will help determine whether the different whistle features between the Chocó dolphins and dolphins from more disturbed areas are a result of the natural acoustic niche hypothesis or a result of noise pollution avoidance. If constructed, the port could force species to adjust their whistle features like populations from noisier habitats already have, and that could disrupt the acoustic niches that already exist, some of their whistles may still be interrupted by boat noise. Such disturbances could increase their stress levels or could lead to area abandonment, which would cause economic and ecological disasters for the region that relies on artisanal fishing and ecotourism.

2pAB – Sound production of the critically endangered totoaba: applying underwater sound detection to fish species conservation

Goldie Phillips – gphillips@sci-brid.com
Sci-Brid International Consulting, LLC
16192 Coastal Hwy
Lewes, DE 19958

Gerald D’Spain – gdspain@ucsd.edu
Catalina López-Sagástegui – catalina@ucr.edu
Octavio Aburto-Oropeza – maburto@ucsd.edu
Dennis Rimington – drimington@ucsd.edu
Dave Price – dvprice@ucsd.edu
Scripps Institution of Oceanography,
University of California, San Diego
9500 Gilman Drive
San Diego, CA 92093

Miguel Angel Cisneros-Mata – macisne@yahoo.com
Daniel Guevara – danyguevara47@hotmail.com
Instituto Nacional de Pesca y Acuacultura (INAPESCA) Mexico
Del Carmen, Coyoacán
04100 Mexico City, CDMX, Mexico

Popular version of paper 2pAB
Presented Tuesday afternoon, December 3rd, 2019
178th ASA Meeting, San Diego, CA

The totoaba (Figure 1), the largest fish of the croaker family, faces a severe illegal fishing threat due largely to the high value of its swim bladder (or buche; Figure 2) in Asian markets. While several conservation measures have been implemented in the Gulf of California (GoC) to protect this endemic species, the totoaba’s current population status remains unknown. Passive acoustic monitoring (PAM) – the use of underwater microphones (called hydrophones) to detect, monitor, and localize sounds produced by soniferous species – offers a powerful means of addressing this problem.

Croaker fishes are well known for their ability to produce sound. Their characteristic “croaking” sound is produced by the vibration of their swim bladder membrane caused by the rapid contraction and expansion of nearby sonic muscles. As sound propagates very efficiently underwater, croaks and other sounds produced by species like the totoaba can be readily detected and recorded by specialized PAM systems.

However, as little is known about the characteristics of totoaba sounds, it is necessary to first gain an understanding of the acoustic behavior of this species before PAM can be applied to the GoC totoaba population. Here we present the first step in a multinational effort to implement such a system.

Totoaba

Figure 1. Totoaba housed at CREMES

Totoaba

Figure 2. Totoaba swim bladder.

We conducted a passive acoustic experiment at the aquaculture center, El Centro Reproductor de Especies Marinas (CREMES), located in Kino Bay, Mexico, between April 29 and May 4, 2019. We collected video and acoustic recordings from totoaba of multiple age classes, both in isolation and within group settings. These recordings were collectively used to characterize the sounds of the totoaba.

We found that in addition to croaks (Video 1) captive totoaba produce 4 other call types, ranging from short duration (<0.03s), low-frequency (<1kHz) narrowband pulses, classified here as “knocks” (Video 2), to longer duration, broadband clicks with significant energy over 10kHz. There is also indication that one of the remaining call types may function as an alarm or distress call. Furthermore, call rates and dominant call type were found to be dependent on age.

Video 1. Visual representation (spectrogram) of a croak produced by totoaba at CREMES. Time (in minutes and seconds) is shown on the x-axis with frequency (in kHz) displayed on the y-axis. Sounds with the greatest amplitude are indicated by warmer colors.

Video 2. Visual representation (spectrogram) of a series of “knocks” produced by totoaba at CREMES.

As PAM systems typically produce large amounts of data that can make manual detections by a human analyst extremely time-consuming, we also used several of the totoaba call types to develop and evaluate multiple automated pre-processing/detector algorithms for a future PAM system in the GoC. Collectively, results are intended to form the basis of a totoaba population assessment that spans multiple spatial and temporal scales.

4aAB4 – A Machine Learning Model of the Global Ambient Sound Level

Shane V. Lympany – shane.lympany@blueridgeresearch.com
Michael M. James – michael.james@blueridgeresearch.com
Alexandria R. Salton
Matthew F. Calton
Blue Ridge Research and Consulting, LLC
29 N Market St, Suite 700
Asheville, NC 28801

Kent L. Gee
Mark K. Transtrum
Katrina Pedersen
Department of Physics and Astronomy
Brigham Young University
Provo, Utah 84602

Popular version of paper 4aAB4
Presented Thursday morning, December 5, 2019
178th ASA Meeting, San Diego, CA

Work funded by an Army SBIR

Traffic on a busy road, birds chirping, rushing water—these are some of the many sounds that make up the ambient soundscape, or acoustic environment, that surrounds us. The ambient soundscape is produced by anthropogenic (man-made) and natural sources, and, in turn, the ambient sound level affects the behavior and well-being of humans and animals. Therefore, it is important to understand how the ambient sound level varies in space. To answer this question, we developed a machine learning model to predict the ambient sound level at every point on Earth’s land surface, and we used the model to estimate the global impact of anthropogenic noise.

First, we trained a machine learning model to identify the relationships between more than 1.5 million hours of ambient sound level measurements and 37 environmental variables, such as population density, land cover, and climate. The model predicts the median sound level in A-weighted decibels (dBA). (A-weighting adjusts the sound level based on how the human ear perceives loudness.)

We applied the machine learning model to predict the median daytime ambient sound level at every point on Earth’s land surface (Figure 1). The loudest sound levels occur in highly populated areas, and the quietest sound levels occur in dry biomes with few humans or animals.

daytime Ambient Sound Level
Figure 1. Median daytime ambient sound level produced by anthropogenic and natural sources.

Next, we estimated the natural sound level (Figure 2) by applying the machine learning model to environmental variables that we modified to remove the influence of humans. The natural sound level is loudest in areas with significant biodiversity, such as rainforests.
daytime Ambient Sound Level
Figure 2. Median daytime ambient sound level produced by natural sources only.

The difference between the overall and natural sound levels (Figure 3) is the amount that anthropogenic noise increases the existing ambient sound level above the natural level. Approximately 5.5 billion people and 28 million square kilometers—an area the size of Russia and Canada combined—are affected by anthropogenic noise that increases the ambient sound level by 3 dBA or more. A 3-dBA increase means that anthropogenic noise is about as loud as the natural sound level. Furthermore, approximately 2.2 billion people and 6.1 million square kilometers—an area the size of the Amazon Rainforest—are affected by anthropogenic noise that increases the ambient sound level by 10 dBA or more. A 10-dBA increase means that anthropogenic noise roughly doubles the perceived loudness of the ambient sound level compared to the natural level.
difference Ambient Sound Level
Figure 3. Difference between the overall and natural ambient sound levels.

In this research, we produced the first-ever global maps of the overall and natural ambient sound levels, and we showed that anthropogenic noise impacts billions of people and vast land areas worldwide. Furthermore, our method for modifying environmental variables is a powerful tool that enables us to predict the effects of future scenarios, such as population growth, urbanization, deforestation, and climate change, on the ambient sound level.

2pAB2
 – Sound pollution decreases the chances of love for oyster toadfish

Rosalyn Putland rputland@d.umn.edu
University of Minnesota Duluth, 1035 Kirby Drive
Duluth, Minnesota 55812

Alayna Mackiewicz alaynam@live.unc.edu
University of North Carolina Chapel Hill, 120 South Road
Chapel Hill, North Carolina 27599

Jacey Van Wert jcvanwert@ucsb.edu
University of California, Santa Barbara
Santa Barbara, California 93106

Allen Mensinger amensing@d.umn.edu
University of Minnesota Duluth, 1035 Kirby Drive
Duluth, Minnesota 55812

Popular version of paper 2pAB2
 Presented Tuesday afternoon, December 3, 2019
178th ASA Meeting, San Diego, California

Despite the famous marine explorer Jacques Cousteau describing the underwater environment as a “silent world”, scientists have discovered sound plays a key role in the lives of many aquatic species. For example, many fishes vocalize to deter predators and attract mates. The oyster toadfish, Opsanus tau, has a rich vocal repertoire, producing a variety of calls with fast contracting muscles along its swimbladder. At the beginning of the mating season, in early summer, male toadfish establish a nest and produce calls termed “boatwhistles” to both announce their territory to competing males and attract females to lay eggs in their nest. However, despite toadfish being studied since 1888, surprisingly little is known about the what part of the song attracts the female, what is the range of the male’s call and the potential effects of sound produced by anthropogenic activity within coastal waters where the toadfish reside.

toadfishFigure 1: Photograph of an oyster toadfish, Opsanus tau. Taken by Allen Mensinger

Therefore, in 2015 the Mensinger lab began conducting passive acoustic monitoring on a resident population of oyster toadfish located in Eel Pond, a small saltwater harbour, adjacent to the Marine Biological Laboratory (MBL) in Woods Hole, Massachusetts. Male toadfish produce unique acoustic signatures in their boatwhistles and the relatively small number of toadfish in the area (< 15) provided an opportunity to study the effect of anthropogenic sound on individual male calling, as males remain in their nests for the entire mating season. Additionally, the movements of large motorized watercraft are restricted by a drawbridge, allowing a natural control, or quiet time, at night when no man-made sound was present. The lab suspended four hydrophones from the dock to record boatwhistles and mathematically compute individual fish locations.

toadfishFigure 2: Toadfish boatwhistles are shown during an 8 second calling window. Three distinct individuals were identified based on waveform shape, spectrogram components and amplitude with one highlight in the box. From Putland et al. 2018.

Toadfish SOUND 1 (1 second)

Toadfish SOUND 2 (1 minute)
Sound clip of oyster toadfish boatwhistles recorded in Eel Pond, Woods Hole, Massachusetts, USA.

Figure 3: Photograph of equipment being deployed at the end of the dock with the research vessel passing by. Taken by Rosalyn Putland

Male toadfish called significantly less following exposure to even brief vessel sound, (5 to 10 minutes) with the motor sound swamping the sound frequency (50 – 500 Hz) and “loudness” of toadfish boatwhistles. Unique sound characteristics of the boatwhistle (pitch, volume, duration) are thought to be used by females to pick the biggest and best mates. For example, larger fish tend to produce lower frequency, louder and longer boatwhistles than smaller individuals. However, exposure to vessel sound could potentially mask the mating call and leave the females swimming aimlessly.

Determining when, where and how often fish, such as the oyster toadfish, are producing sound allows acoustically sensitive times and areas to be prioritized during management strategy. For example, vessel speed restrictions or restricted boat traffic could be enforced to reduce sound levels during critical spawning periods. The male fish is considered by many to be unattractive and does not need man made sound interfering with his love song.

4aAB1 – The best available science? Are NOAA Fisheries marine mammal exposure noise guidelines up to date?

Michael Stocker – mstocker@OCR.org
Ocean Conservation Research
P.O. Box 559
Lagunitas, California 94938

Popular version of paper 4aAB1
Presented Thursday morning, May 16, 2019
177th ASA Meeting, Louisville, KY
Click here tor read the abstract
Click here to read the proceedings paper

Abstract
NOAA Fisheries employs a set of in-water noise exposure guidelines that establish regulatory thresholds for ocean actions that impact marine mammals. These are established based on two impact criteria: Level A – a physiological impact, and Level B – a behavioral impact or disruption. Since the introduction of these exposure definitions, much more work has been published on behavioral impacts of various noise exposures, and consideration of other variables such as frequency, sound quality, and multiple sound-source exposures. But these variables have not yet been incorporated into the NOAA Fisheries exposure guidelines.

Determining regulatory thresholds
In the Marine Mammal Protection Act (MMPA) sound exposure levels are categorized in two levels, Level A” and “Level B.” “Level A Take” defined by the National Marine Fisheries Service (NMFS) as a “do not exceed” threshold below which physical injury would not occur. In whales and whales, dolphins, and porpoises this was 180dB (re: 1μPa).

A “Level B Take” is defined as “any act that disturbs or is likely to disturb a marine mammal or marine mammal stock in the wild by causing disruption of natural behavioral patterns, including, but not limited to, migration, surfacing, nursing, breeding, feeding, or sheltering, to a point where such behavioral patterns are abandoned or significantly altered.” But defining what constitutes “disruption” is fraught with threshold vagaries – given that behavior is always contextual, and the weight of the “biological significance” of the disruption hinges on a human value scale. How biologically significant is it when Bowhead whales change their vocalization rates in response to barely audible airgun exposure, well below the Level B threshold? How biologically significant is it when a sea lion risks exposure to loud, intentionally (above Level A) Acoustic Harassment Devices intended to scare sea lions away from fish farms actually attracts them by letting them know that “dinner” is available.

Regulatory Metrics
Regulations work best when they are unambiguous. Regulators are not fond of nuance. Dichotomous decisions of Yes/No, Go/No-Go are their stock and trade. It was for this reason that until just recently the marine mammal exposure guidelines were really simple:

Noise exposure above 180dB = Level A exposure.
Noise exposure above 160dB = Level B exposure (for impulsive sounds)
Noise exposure above 120dB = Level B exposure (for continuous sounds)

But it was clear that these original regulatory thresholds were actually too simple. When dolphins ride the bow waves of seismic survey vessels – frolicking in a Level A noise field, it was apparent that the regulatory thresholds did not reflect common field conditions. This was recently addressed in guidelines that more accurately reflected the noise exposure criteria relative to the hearing ranges of a range of the various marine mammal species – from large “Low Frequency” baleen whales, to small “High Frequency” dolphins and porpoises. While this new standard more accurately reflects the frequency-defined hearing ranges of the exposed animals, it does not accurately address the complexity of the noise exposures in terms of sound qualities, nor in terms of the complexity of the sound environments in which the exposures would typically occur.

Actual sound exposures
Increasingly complex signals are being used in the sea for underwater communication and equipment control. These communication signals can be rough or “screechy” sounding and more disturbing and more damaging than the simple signals used for auditory testing.

Additionally, when sounds presented in a typical Environmental Impact Statements, they are presented as single sources of sound. And while there is some consideration for accumulated noise impacts, the accumulation period “resets” after 24 hours, so the metric only reflects accumulated noise exposure and does not address the impacts of a habitat completely transformed by continuous, or ongoing noise. Given that typical seismic airgun surveys run around the clock for weeks to months at a time, and have an acoustical reach of hundreds to thousands of kilometers, the activity is likely to have much greater behavioral impact than is reflected in accumulating and dumping of a noise exposure index every 24 hours.

Furthermore, operations such as seismic survey, or underwater extraction industry operations typically use a lot of different, but simultaneous sound sources. Seismic surveys may include seafloor profiling with multi-beam or side-scan sonars. Underwater extraction industries such as seafloor processing for oil and gas extraction, or seafloor mining operations will necessarily have multiple sound sources – with noisy equipment, along with acoustical communications for status monitoring, and acoustical remote control of the equipment. These concurrently operating compliments of equipment can create a very complex soundscape. And even if the specific pieces of equipment don’t in-and-of-themselves exceed regulatory thresholds, they may nonetheless create acoustically-hostile soundscapes likely to have behavioral and metabolic impacts on marine animals. So far there is no qualitative metrics for compromised soundscapes, but modeling for concurrent sound exposures is possible, and in this context, many concurrent sounds would constitute “continuous sound,” thereby qualifying the soundscape as a whole under the Level B continuous sound criteria of 120dB.

This is particularly the case for a proposed set of seismic surveys in the Mid-Atlantic, wherein three separate geophysical surveys would be occurring simultaneously in close proximity. “Incidental Harassment Authorizations” have been released by NOAA Fisheries for these surveys which have not taken the ‘concurrent noise exposures’ into account.

Additionally, while sound sources in the near-field may be considered “impulsive sounds.” And thus regulated under “Level B” criteria for impulse sounds, due to reverberation, louder sounds which have a long reach should be considered as “continuous sound sources” and thus be regulated under the Level B ‘continuous sound’ criteria of 120dB.

Recommendations:
1. NOAA sound exposure metric should be updated to reflect sound quality (accommodating for signal characteristics) as well as amplitude.
2. “Soundscapes” need qualitative and quantitative definitions, and then incorporated into the regulatory framework.
3. Exposure metrics needs to accommodate for concurrent sound source exposures.
4. The threshold for what constitutes “continuous sound” needs to be more clearly defined, particularly in terms of loud sound sources in the far field subject to reverberation and “multi-path” echoes.