A large-scale experiment finds no consistent evidence of change in mortality or commercial productivity in silverlip pearl oysters (Pinctada maxima) exposed to a seismic source survey.

High-intensity, impulsive sounds are used to locate oil and gas reserves during seismic exploration of the seafloor. The impacts of this noise pollution on the health and mortality of marine invertebrates are not well known, including the silverlip pearl oyster (Pinctada maxima), which comprises one of the world's last remaining significant wildstock pearl oyster fisheries, in northwestern Australia. We exposed ≈11,000 P. maxima to a four-day experimental seismic survey, plus one vessel-control day. After exposure, survival rates were monitored throughout a full two-year production cycle, and the number and quality of pearls produced at harvest were assessed. Oysters from two groups, on one sampling day, exhibited reduced survival and pearl productivity compared to controls, but 14 other groups receiving similar or higher exposure levels did not. We therefore found no conclusive evidence of an impact of the seismic source survey on oyster mortality or pearl production.

Global inventory of species categorized by known underwater sonifery.

A working group from the Global Library of Underwater Biological Sounds effort collaborated with the World Register of Marine Species (WoRMS) to create an inventory of species confirmed or expected to produce sound underwater. We used several existing inventories and additional literature searches to compile a dataset categorizing scientific knowledge of sonifery for 33,462 species and subspecies across marine mammals, other tetrapods, fishes, and invertebrates. We found 729 species documented as producing active and/or passive sounds under natural conditions, with another 21,911 species deemed likely to produce sounds based on evaluated taxonomic relationships. The dataset is available on both figshare and WoRMS where it can be regularly updated as new information becomes available. The data can also be integrated with other databases (e.g., SeaLifeBase, Global Biodiversity Information Facility) to advance future research on the distribution, evolution, ecology, management, and conservation of underwater soniferous species worldwide.

Habitat type drives the spatial distribution of Australian fish chorus diversitya).

Fish vocalize in association with life functions with many species calling en masse to produce choruses. Monitoring the distribution and behavior of fish choruses provides high-resolution data on fish distribution, habitat use, spawning behavior, and in some circumstances, local abundance. The purpose of this study was to use long-term passive acoustic recordings to obtain a greater understanding of the patterns and drivers of Australian fish chorus diversity at a national scale. This study detected 133 fish choruses from year-long recordings taken at 29 Australian locations with the highest fish chorus diversity identified at a site in the country's northern, tropical waters. A linear model fitted with a generalized least squares regression identified geomorphic feature type, benthic substrate type, and northness (of slope) as explanatory variables of fish chorus diversity. Geomorphic feature type was identified as the significant driver of fish chorus diversity. These results align with broad-scale patterns reported previously in fish biodiversity, fish assemblages, and fish acoustic diversity. This study has highlighted that passive acoustic monitoring of fish chorus diversity has the potential to be used as an indicator of fish biodiversity and to highlight habitats of ecological importance.

Surgical Approach and Dislocation Risk After Hemiarthroplasty in Geriatric Patients With Femoral Neck Fracture With and Without Cognitive Impairments-Does Cognitive Impairment Influence Dislocation Risk?

OBJECTIVES: To determine whether there is an association between surgical approach and dislocation risk in patients with cognitive impairment compared with those without cognitive impairment treated with hemiarthroplasty for femoral neck fracture. DESIGN: Retrospective study. SETTING: Large, multicenter health system. PATIENTS/PARTICIPANTS: One thousand four hundred eighty-one patients who underwent hemiarthroplasty for femoral neck fractures. 828 hips met inclusion criteria, 290 (35.0%) were cognitively impaired, and 538 (65.0%) were cognitively intact. INTERVENTION: Hemiarthroplasty. MAIN OUTCOME MEASURE: Prosthetic hip dislocation. RESULTS: The overall dislocation rate was 2.1% (17 of 828), 3.4% (10 of 290) in the cognitively impaired group, and 1.3% (7 of 538) in the cognitively intact group with a median time to dislocation of 20.5 days (range 2-326 days), 24.5 days (range 3-326 days), and 19.0 days (range 2-36 days), respectively. In the entire cohort, there were no dislocations (0 of 58) with the direct anterior approach (DA); 1.1% (6 of 553) and 5.1% (11 of 217) dislocated with the modified Hardinge (MH) and posterior approaches (PA), respectively. In the cognitively impaired group, there were no dislocations with the DA (0 of 19); 1.5% (3 of 202) and 10.1% (7 of 69) dislocated with the MH and PA, respectively. In the cognitively intact group, there were no dislocations (0 of 39) with the DA; 0.85% (3 of 351) and 2.7% (4 of 148) dislocated with the MH and PA, respectively. There were statistically significant associations between surgical approach and dislocation in the entire cohort and the cognitively impaired group when comparing the MH and PA groups. This was not observed in the cognitively intact group. Patients who dislocated had 3.2 times (95% CI 1.2, 8.7) ( P = 0.0226) the hazard of death compared with patients who did not dislocate. Dislocation effectively increased the risk of death by 221% (HR 3.2 95% CI 1.2, 8.7) ( P = 0.0226). CONCLUSIONS: In this patient population, the PA has a higher dislocation rate than other approaches and has an especially high rate of dislocation when the patients were cognitively impaired. The authors of this study suggest careful consideration of surgical approach when treating these injuries. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

A large-scale experiment finds no evidence that a seismic survey impacts a demersal fish fauna.

Seismic surveys are used to locate oil and gas reserves below the seabed and can be a major source of noise in marine environments. Their effects on commercial fisheries are a subject of debate, with experimental studies often producing results that are difficult to interpret. We overcame these issues in a large-scale experiment that quantified the impacts of exposure to a commercial seismic source on an assemblage of tropical demersal fishes targeted by commercial fisheries on the North West Shelf of Western Australia. We show that there were no short-term (days) or long-term (months) effects of exposure on the composition, abundance, size structure, behavior, or movement of this fauna. These multiple lines of evidence suggest that seismic surveys have little impact on demersal fishes in this environment.

The soundscape of the Anthropocene ocean.

Oceans have become substantially noisier since the Industrial Revolution. Shipping, resource exploration, and infrastructure development have increased the anthrophony (sounds generated by human activities), whereas the biophony (sounds of biological origin) has been reduced by hunting, fishing, and habitat degradation. Climate change is affecting geophony (abiotic, natural sounds). Existing evidence shows that anthrophony affects marine animals at multiple levels, including their behavior, physiology, and, in extreme cases, survival. This should prompt management actions to deploy existing solutions to reduce noise levels in the ocean, thereby allowing marine animals to reestablish their use of ocean sound as a central ecological trait in a healthy ocean.

The use of singlebeam echo-sounder depth data to produce demersal fish distribution models that are comparable to models produced using multibeam echo-sounder depth.

Seafloor characteristics can help in the prediction of fish distribution, which is required for fisheries and conservation management. Despite this, only 5%-10% of the world's seafloor has been mapped at high resolution, as it is a time-consuming and expensive process. Multibeam echo-sounders (MBES) can produce high-resolution bathymetry and a broad swath coverage of the seafloor, but require greater financial and technical resources for operation and data analysis than singlebeam echo-sounders (SBES). In contrast, SBES provide comparatively limited spatial coverage, as only a single measurement is made from directly under the vessel. Thus, producing a continuous map requires interpolation to fill gaps between transects. This study assesses the performance of demersal fish species distribution models by comparing those derived from interpolated SBES data with full-coverage MBES distribution models. A Random Forest classifier was used to model the distribution of Abalistes stellatus, Gymnocranius grandoculis, Lagocephalus sceleratus, Loxodon macrorhinus, Pristipomoides multidens, and Pristipomoides typus, with depth and depth derivatives (slope, aspect, standard deviation of depth, terrain ruggedness index, mean curvature, and topographic position index) as explanatory variables. The results indicated that distribution models for A. stellatus, G. grandoculis, L. sceleratus, and L. macrorhinus performed poorly for MBES and SBES data with area under the receiver operator curves (AUC) below 0.7. Consequently, the distribution of these species could not be predicted by seafloor characteristics produced from either echo-sounder type. Distribution models for P. multidens and P. typus performed well for MBES and the SBES data with an AUC above 0.8. Depth was the most important variable explaining the distribution of P. multidens and P. typus in both MBES and SBES models. While further research is needed, this study shows that in resource-limited scenarios, SBES can produce comparable results to MBES for use in demersal fish management and conservation.

Listening forward: approaching marine biodiversity assessments using acoustic methods.

Ecosystems and the communities they support are changing at alarmingly rapid rates. Tracking species diversity is vital to managing these stressed habitats. Yet, quantifying and monitoring biodiversity is often challenging, especially in ocean habitats. Given that many animals make sounds, these cues travel efficiently under water, and emerging technologies are increasingly cost-effective, passive acoustics (a long-standing ocean observation method) is now a potential means of quantifying and monitoring marine biodiversity. Properly applying acoustics for biodiversity assessments is vital. Our goal here is to provide a timely consideration of emerging methods using passive acoustics to measure marine biodiversity. We provide a summary of the brief history of using passive acoustics to assess marine biodiversity and community structure, a critical assessment of the challenges faced, and outline recommended practices and considerations for acoustic biodiversity measurements. We focused on temperate and tropical seas, where much of the acoustic biodiversity work has been conducted. Overall, we suggest a cautious approach to applying current acoustic indices to assess marine biodiversity. Key needs are preliminary data and sampling sufficiently to capture the patterns and variability of a habitat. Yet with new analytical tools including source separation and supervised machine learning, there is substantial promise in marine acoustic diversity assessment methods.

Reducing vessel noise: An example of a solar-electric passenger ferry.

Concern over the impacts of anthropogenic noise on aquatic fauna is increasing, as is the number of vessels in the world's oceans, lakes, and rivers. Sound signatures of different vessel types are increasingly characterized, yet few reports are available on solar-electric powered vessels. Such data are important to model the sound levels experienced by marine fauna and their potential impacts. Sounds from two vessel types were recorded in the shallow waters of the Swan River, Western Australia, using bottom-mounted OceanInstruments SoundTraps. Multiple passes from two 10-m solar-electric powered passenger ferries and, for comparison, two 25-m conventionally powered (inboard diesel engine) passenger ferries were selected. Analysis was conducted on 58 and 16 passes by the electric ferries (in 2016 and 2017-2018, respectively) and 10 and 14 passes by the conventional ferry (2016 and 2017-2018, respectively) at 5-m range. At 55-m range, analysis was conducted on 17 and 1 passes by the electric ferry (2016 and 2017-2018, respectively) and 9 and 3 passes of the conventional ferry (2016 and 2017-2018, respectively). Measured received levels and modeled sound propagation were then used to estimate monopole source levels (MSL) and radiated noise levels (RNL). At 55-m range, the conventionally powered ferry type produced 156 and 157 dB re 1 µPa2m2 MSL and RNL, respectively, while the same metrics for the electric ferry were 12 dB lower. At frequencies below 500 Hz, spectral levels of the electric ferry at a range of <5 m were 10-25 dB lower than those of the conventional ferry, implying a potential benefit for animals that use low-frequency communication, if electric motors replaced petrol or diesel engines.

Fin whale (Balaenoptera physalus) migration in Australian waters using passive acoustic monitoring.

The fin whale is a globally endangered species and is listed as threatened in Australia, however no peer-reviewed studies are available to indicate the migratory movements of the species in Australian waters. This study uses passive acoustic monitoring as a tool to identify the migratory movements of fin whales in Australian waters. Sampling was conducted from eight locations around Australia between 2009 and 2017, providing a total of 37 annual migratory records. Taken together, our observations provide evidence of fin whale migration through Australian waters, with earliest arrival of the animals recorded on the Western Australian coast, at Cape Leeuwin in April. The whales travel through Cape Leeuwin, migrating northward along the Western Australian coast to the Perth Canyon (May to October), which likely acts as a way-station for feeding. Some whales continue migrating as far north as Dampier (19°S). On Australia's east coast, at Tuncurry, fin whale seasonal presence each year occurred later, from June to late September/October. A total of only 8,024 fin whale pulses were recorded on the east coast, compared to 177,328 pulses recorded at the Perth Canyon. We suggest these differences, as well as the spatial separation between coasts, provide preliminary evidence that the fin whales present on the east and west coasts constitute separate sub-populations.

Underwater noise from airplanes: An overlooked source of ocean noise.

The effects of underwater noise pollution on marine life are of increasing concern. Research and management have focussed on the strongest underwater sound sources. Aerial sound sources have understandably been ignored as sound transmits poorly across the air-water interface. However, there might be situations when air-borne noise cannot be dismissed. Commercial passenger airplanes were recorded in a coastal underwater soundscape exhibiting broadband received levels of 84-132 dB re 1 µPa rms. Power spectral density levels of airplane noise underwater exceeded ambient levels between 12 Hz and 2 or 10 kHz (depending on site) by up to 36 dB. Underwater noise from airplanes is expected to be audible to a variety of marine fauna, including seals, manatees, and dolphins. With many of the world's airports lying close to the coast, it is cautioned that airplane noise not be ignored, in particular in the case of at-risk species in small, confined habitats.

Patterns of biophonic periodicity on coral reefs in the Great Barrier Reef.

The coral reefs surrounding Lizard Island in the Great Barrier Reef have a diverse soundscape that contains an array of bioacoustic phenomena, notably choruses produced by fishes. Six fish choruses identified around Lizard Island exhibited distinctive spatial and temporal patterns from 2014 to 2016. Several choruses displayed site fidelity, indicating that particular sites may represent important habitat for fish species, such as fish spawning aggregations sites. The choruses displayed a broad range of periodicities, from diel to annual, which provides new insights into the ecology of vocalising reef fish species and the surrounding ecosystem. All choruses were affected by one or more environmental variables including temperature and moonlight, the latter of which had a significant influence on the timing and received sound levels. These findings highlight the utility of passive acoustic tools for long-term monitoring and management of coral reefs, which is highly relevant in light of recent global disturbance events, particularly coral bleaching.

Percutaneous freezing of sensory nerves prior to total knee arthroplasty.

BACKGROUND: Total knee arthroplasty (TKA) is a common procedure resulting in significant post-operative pain. Percutaneous cryoneurolysis targeting the infrapatellar branch of the saphenous nerve and anterior femoral cutaneous nerve could relieve post-operative knee pain by temporarily blocking sensory nerve conduction. METHODS: A retrospective chart review of 100 patients who underwent TKA was conducted to assess the value of adding perioperative cryoneurolysis to a multimodal pain management program. The treatment group consisted of the first 50 patients consecutively treated after the practice introduced perioperative (five days prior to surgery) cryoneurolysis as part of its standard pain management protocol. The control group consisted of the 50 patients treated before cryoneurolysis was introduced. Outcomes included hospital length of stay (LOS), post-operative opioid requirements, and patient-reported outcomes of pain and function. RESULTS: A significantly lower proportion of patients in the treatment group had a LOS of ≥2days compared with the control group (6% vs. 67%, p<0.0001) and required 45% less opioids during the first 12weeks after surgery. The treatment group reported a statistically significant reduction in symptoms at the six- and 12-week follow-up compared with the control group and within-group significant reductions in pain intensity and pain interference at two- and six-week follow-up, respectively. CONCLUSIONS: Perioperative cryoneurolysis in combination with multimodal pain management may significantly improve outcomes in patients undergoing TKA. Promising results from this preliminary retrospective study warrant further investigation of this novel treatment in prospective, randomized trials. LEVEL OF EVIDENCE: III.

Sound production by the West Australian dhufish (Glaucosoma hebraicum).

Biological examinations of Glaucosomatid fish species have suggested that they could produce sound via swimbladder vibration, using "sonic" muscles. However, there have been few reported instances of it in the family. West Australian dhufish (Glaucosoma hebraicum) is an iconic teleost, endemic to Western Australia. Dissection of G. hebraicum in this study identified the presence of "sonic" muscle pairs in immature and sexually mature individuals. The muscle tissue originates in the otic region of the skull with its insertion at the anterior of the swimbladder. Recordings of sounds were acquired from two male G. hebraicum, at a range of 1 m, during capture. Calls comprised 1 to 14 swimbladder pulses with spectral peak frequency of 154 ± 45 Hz (n = 67 calls) and 3 dB bandwidth of 110 ± 50 Hz. The mean of all call maximum source levels was 126 dB re 1 µPa at 1 m with the highest level at 137 dB re 1 µPa at 1 m. The confirmation of sound production by G. hebraicum and the acoustic characteristics of those sounds could be used to gain a better understanding of its ecology and, particularly, whether the production of sound is associated with specific behaviors, such as reproduction.

Source levels of dugong (Dugong dugon) vocalizations recorded in Shark Bay.

Dugongs (Dugong dugon) spend significant time in shallow, turbid waters and are often active at night, conditions which are not conducive to visual cues. In part, as a result, dugongs vocalize to gain or pass information. Passive acoustic recording is a useful tool for remote detection of vocal marine animals, but its application to dugongs has been little explored compared with other mammals. Aerial surveys, often used to monitor dugong distribution and abundance, are not always financially or logistically viable and involve inherent availability and perception bias considerations. Passive acoustic monitoring is also subject to sampling biases and a first step to identifying these biases and understanding the detection or communication range of animal calls is to determine call source level. In March 2012, four dugongs were fitted with satellite tags in Shark Bay, Western Australia by the Department of Environment and Conservation. During this, acoustic recordings were taken at 5.1 m range. Source levels for each of five call types (two types of chirp, bark, squeak, and quack) were estimated, assuming spherical spreading as the transmission loss. Mean source levels for these call types were 139 (n = 19), 135 (12), 142 (2), 158 (1), and 136 (9) dB re 1 µPa at 1 m, respectively.

In situ source levels of mulloway (Argyrosomus japonicus) calls.

Mulloway (Argyrosomus japonicus) in Mosman Bay, Western Australia produce three call categories associated with spawning behavior. The determination of call source levels and their contribution to overall recorded sound pressure levels is a significant step towards estimating numbers of calling fish within the detection range of a hydrophone. The source levels and ambient noise also provide significant information on the impacts anthropogenic activity may have on the detection of A. japonicus calls. An array of four hydrophones was deployed to record and locate individual fish from call arrival-time differences. Successive A. japonicus calls produced samples at various ranges between 1 and 100 m from one of the array hydrophones. The three-dimensional localization of calls, together with removal of ambient noise, allowed the determination of source levels for each call category using observed trends in propagation losses and interference. Mean source levels (at 1 m from the hydrophone) of the three call categories were calculated as 163 ± 16 dB re 1 µPa for Category 1 calls (short call of 2-5 pulses); 172 ± 4 dB re 1 µPa for Category 2 calls (long calls of 11-32 pulses); and 157 ± 5 dB re 1 µPa for Category 3 calls (series of successive calls of 1-4 pulses, increasing in call rate).