Acoustic Monitoring Data Research Articles

Moving Forward in a Reverse Estuary: Habitat Use and Movement Patterns of Black Drum (Pogonias cromis) Under Distinct Hydrological Regimes

Understanding the effects of freshwater inflow on estuarine fish habitat use is critical to the sustainable management of many coastal fisheries. The Baffin Bay Complex (BBC) of south Texas is typically a reverse estuary (i.e., salinity increases upstream) that has supported many recreational and commercial fisheries. In 2012, a large proportion of black drum (Pogonias cromis) landed by fishers were emaciated, leading to concerns about the health of this estuary. In response to this event and lacking data on black drum spatial dynamics, a 2-year acoustic telemetry study was implemented to monitor individual-based movement and seasonal distribution patterns. Coupled with simultaneous water quality monitoring, the relationship between environmental variables and fish movement was assessed under reverse and “classical” estuary conditions. Acoustic monitoring data suggested that the BBC represents an important habitat for black drum; individuals exhibited site fidelity to the system and were present for much of the year. However, under reverse estuary conditions, fish summertime distribution was constrained to the interior of the BBC, where food resources are limited (based on recent benthic sampling), with little evidence of movement across the system. Out of eight environmental variables used to model fish movement using multiple linear regression, the only significant variable was salinity, which exhibited a negative relationship with movement rate. These findings suggest that prolonged periods of hypersalinity, which are detrimental to other euryhaline species due to increased osmoregulatory costs, reduce black drum distribution patterns and can limit the species’ access to benthic habitats supporting abundant prey resources.

Vessel noise cuts down communication space for vocalizing fish and marine mammals.

Anthropogenic noise across the world's oceans threatens the ability of vocalizing marine species to communicate. Some species vocalize at key life stages or whilst foraging, and disruption to the acoustic habitat at these times could lead to adverse consequences at the population level. To investigate the risk of these impacts, we investigated the effect of vessel noise on the communication space of the Bryde's whale Balaenoptera edeni, an endangered species which vocalizes at low frequencies, and bigeye Pempheris adspersa, a nocturnal fish species which uses contact calls to maintain group cohesion while foraging. By combining long-term acoustic monitoring data with AIS vessel-tracking data and acoustic propagation modelling, the impact of vessel noise on their communication space was determined. Routine vessel passages cut down communication space by up to 61.5% for bigeyes and 87.4% for Bryde's whales. This influence of vessel noise on communication space exceeded natural variability for between 3.9 and 18.9% of the monitoring period. Additionally, during the closest point of approach of a large commercial vessel, <10km from the listening station, the communication space of both species was reduced by a maximum of 99% compared to the ambient soundscape. These results suggest that vessel noise reduces communication space beyond the evolutionary context of these species and may have chronic effects on these populations. To combat this risk, we propose the application or extension of ship speed restrictions in ecologically significant areas, since our results indicate a reduction in sound source levels for vessels transiting at lower speeds.

Feeding and social activity of insectivorous bats in a complex landscape: The importance of gallery forests and karst areas

Worldwide, increasing human activity, such as agriculture and mining, and decreased landscape complexity, are negatively affecting numerous mammal species. For example, bat communities are becoming threatened in many locations mostly due to the loss of their preferred roosting and foraging habitats. Brazilian landscapes and their associated bat communities are no exception, with the situation being further exacerbated by recently adopted permissive environmental laws that have resulted in reduced biodiversity protection and conservation. Therefore, there is an urgent need to understand how landscape and environmental variables relate to bat activities in Brazil in order to support efforts for their conservation. We used acoustic monitoring data to investigate differences in foraging and social activity of insectivorous bats among four habitat types in a heterogeneous landscape in the Cerrado-Atlantic forest ecotone in southeastern Brazil. We also sampled insect availability and measured temperature at the same sites. Our results showed increased social activity and a greater number of species emitting social calls in karst, and increased feeding activity with a greater number of species emitting feeding buzzes in gallery forest. We also found a positive influence of both temperature and insect abundance on foraging and social activity. Our study provides new insights regarding habitat use by bats in a heterogeneous landscape, and demonstrates the importance of preserving different habitats in heterogeneous landscapes for the conservation of bat species and the ecological functions they perform.

A Bayesian Probabilistic Approach for Acoustic Emission‐Based Rail Condition Assessment

AbstractThe investigation described in this article aims at developing a Bayesian‐based approach for probabilistic assessment of rail health condition using acoustic emission monitoring data. It comprises the following three phases: (i) formulation of a frequency‐domain structural health index (SHI), via a linear transformation method, tailored to damage‐sensitive frequency bandwidth; (ii) establishment of data‐driven reference models, using Bayesian regression about the real and imaginary parts of the SHI derived with monitoring data from the intact rail; and (iii) quantitative evaluation of discrimination between the new observations representative of current rail health condition and the baseline model predictions in terms of Bayes factor. If the deviation of the new observations from the predictions is within an acceptable tolerance, no damage is flagged, and the new data are further used to update and refine the reference models. If the observations deviate substantially from the model predictions in a probabilistic sense, damage is signaled, damage severity is quantified, and damage location determined. The proposed approach is examined by using field monitoring data acquired from an instrumented railway turnout, and the coincidence between the assessment results and the actual health conditions demonstrates its effectiveness in damage detection, localization, and quantification.

Decadal assessment of the sperm whale population trends in the northern Gulf of Mexico using acoustics

Passive acoustic monitoring data have been used to assess population trends of sperm whales in the northern Gulf of Mexico. In this paper, the variability of sperm whale abundance in the Mississippi Canyon area derived from acoustic data collected between 2001 and 2017 is discussed in relation to seasons, habitat type, ambient noise levels, and environmental disturbances. The results have shown that sperm whales were present in the region throughout the entire monitoring period with lower activity in winter months. A considerable habitat shift was observed after the 2010 oil spill with sperm whale activity higher at the sites further away from the spill site. The results clearly indicate the importance of long-term spatially distributed acoustic monitoring in characterizing changes in Gulf of Mexico marine mammal population and their habitat.

Species-level classification and clustering of beaked whale echolocation recordings

The Littoral Acoustic Demonstration Center—Gulf Ecological Monitoring and Modeling (LADC-GEMM) consortium has collected passive acoustic monitoring data in the northern Gulf of Mexico since 2001. Recordings were made in 2007 near the Deepwater Horizon oil spill, which have provided a baseline for an extensive study of regional marine mammal populations in response to the disaster. Beaked whales are of particular interest as they remain one of the least understood groups of marine mammals, and relatively few abundance estimates exist. Efficient classification and clustering algorithms are demanded for mining the long-term passive acoustic data. Three algorithms using k-means, self-organizing maps, and spectral clustering are tested with various features of detected echolocation transients. Several methods are observed to effectively isolate recorded echolocation clicks of regional beaked whale species. The waveform fractal dimension is introduced as a feature for marine biosonar classification and shown to improve accuracy. A feedforward neural network classifier is also evaluated and shows performance with high accuracy under various noise conditions. [This research was made possible by a grant from The Gulf of Mexico Research Initiative. Data are publicly available through the Gulf of Mexico Research Initiative Information &amp; Data Cooperative (GRIIDC) at https://data.gulfresearchinitiative.org.]

Acoustic monitoring data of avian species inside and outside the evacuation zone of the Fukushima Daiichi power plant accident

AbstractLarge‐scale land abandonment and reconstruction activity has altered the ecosystem structure in the evacuation area for the Fukushima Daiichi power plant accident in 2011. Despite social concerns about changes in the avian assemblages that occurred after the accident, publicly accessible data are quite limited. We engaged in acoustic monitoring of birds using digital voice recorders from 2014 in and around the Fukushima evacuation zone. All monitoring sites were located within schoolyards (including those that had been converted to community centers) to examine the bird assemblages in the urban and rural landscapes that were heavily altered by land abandonment due to the nuclear plant accident. A digital voice recorder was installed at each monitoring site during May–July, and we recorded 20 min a day using timer‐recording mode. We divided the audio data into 1‐min segments and identified species occurred in sampled segments by experts. These data represent the presence‐absence records from 52 sites monitored in 2014. In 2014, we identified the species for 7138 segments in total and 68 species occurred. We are continuing to monitor and intend to update the dataset with new observations hereafter. Our dataset will help people to recognize the status and dynamics of avian assemblage inside the evacuation zone, and will contribute to promote open science in avian ecological studies.

Seasonal acoustic behavior of blue whales (Balaenoptera musculus) in the Gulf of California, Mexico

AbstractSix years of passive acoustic monitoring data from the Gulf of California reveal seasonality and movements for the northeastern Pacific blue whales. Three sites were studied, one from the southern (Punta Pescadero) and two from the northern (Isla Tiburon and Canal de Ballenas) regions. A total of 4,953 h were analyzed, and 15,539 blue whale calls were detected, of which 2,723 (18%) were A calls, 11,249 were B calls (72%), and 1,567 were D calls (10%). A and B calls were produced both as song units (2,524) or AB singular calls (2,026). The high rate of songs and their seasonality suggest that the GC is a winter‐breeding ground. A shift from AB call predominance in winter, to D calls in spring and early summer, especially at the entrance of the GC, suggests the importance of this area for reproduction and foraging. Analysis of calling frequency suggests a clear movement of blue whales from the southern region (Punta Pescadero) to the northern regions (Canal de Ballenas and Isla Tiburon), with subsequent southern movement in March. The seasonality and mobility of blue whales in the Gulf of California, inferred from their calling, contributes to the ecological understanding of this population.

Evaluating underwater ambient noise levels across a changing Arctic environment

As a result of climate change, the Arctic underwater acoustic environment is undergoing an unprecedented transformation of its ambient noise sources, including an expanded wind fetch over open water and an intensification of maritime transportation lanes across Northern routes. This comparative study synthesizes multi-annual passive acoustic monitoring (PAM) data collected at various Alaskan Arctic environments (Bering Strait, Chukchi Plateau, Chukchi, and Beaufort Seas) in order to evaluate the statistics of ambient noise across the changing region. Mean levels at significant frequency ranges are presented, as well as percentile PSD levels in 1-Hz frequency bins. Remote sensing sea ice data is utilized to separate each annual dataset into 3 different regimes: open water, covered, and transition (when ice is forming or breaking up). During each, the dominant large-scale noise sources are characterized and the relationship between noise and local wind speed is evaluated. Through manual inspection, ship transits and seismic surveys have been extracted, allowing ambient level associations on the scale of hours or days. Consistently across all years, the Chukchi Plateau site, which is the most distant from shore, presents the lowest overall ambient noise levels (20-40 dB lower than other locations), potentially indicating a new Arctic ambient noise baseline.

Long-term spatially distributed observations of deep diving marine mammals in the Northern Gulf of Mexico using passive acoustic monitoring

This paper will present the results of processing long-term passive acoustic monitoring (PAM) data collected July through October 2015 in the Northern Gulf of Mexico in the vicinity of the Deep Water Horizon oil spill site to aid in understanding factors driving the distribution of sperm and beaked whales in the Gulf of Mexico. The Littoral Acoustic Demonstration Center -Gulf Ecological Monitoring and Modeling Consortium (LADC-GEMM) deployed five bottom-anchored acoustic moorings (LADC EARS buoys) at 10, 25, and 50 nmi distance from the 2010 oil spill location. Autonomous surface vehicles and a glider were simultaneously operated in the area for the additional collection of PAM data. The daily and monthly activity of three species of beaked whales exhibits spatial and seasonal variability, which appear to be correlated with levels of anthropogenic noise at the monitoring sites. Acoustic detection data are used to estimate abundances at three sites and compare them to the estimates obtained from baseline data collected before (2007) and right after (2010) the oil spill. Long-term abundance trends for both beaked and sperm whales are discussed. [Research supported by GOMRI.]

Passive acoustic monitoring of Pygmy blue whales (Balaenoptera musculus brevicauda) in Southern Sri Lanka

Two ecological acoustic recorders were deployed in Southern Sri Lanka to study the presence of the assumed resident population of pygmy blue whales. A major shipping lane runs through this feeding area of the whales and it has been recognized by the International Whaling Commission as well as International Maritime Organization as a risk area for ship strikes. To implement any management practices to mitigate ship strikes, a solid scientific basis is needed. Such data must include information on migration and movement patterns of the whale population. Therefore, combining the passive acoustic monitoring data with existing visual transect survey results gives further insight to choosing suitable management practices to address the issue. Passive acoustic monitoring data indicate that at least part of the population is indeed resident in the area throughout the year but there is both seasonal and inter-annual variation in the acoustic activity of the whales. The acoustic data were further combined with data...

Spatio-temporal patterns in acoustic presence and distribution of Antarctic blue whales Balaenoptera musculus intermedia in the Weddell Sea

Distribution and movement patterns of Antarctic blue whales Balaenoptera musculus intermedia at large temporal and spatial scales are still poorly understood. The objective of this study was to explore spatio-temporal distribution patterns of Antarctic blue whales in the Atlantic sector of the Southern Ocean, using passive acoustic monitoring data. Multi-year data were collected between 2008 and 2013 by 11 recorders deployed in the Weddell Sea and along the Greenwich meridian. Antarctic blue whale Z-calls were detected via spectrogram cross-correlation. A Blue Whale Index was developed to quantify the proportion of time during which acoustic energy from Antarctic blue whales dominated over background noise. Our results show that Antarctic blue whales were acoustically present year-round, with most call detections between January and April. During austral summer, the number of detected calls peaked synchronously throughout the study area in most years, and hence, no directed meridional movement pattern was detectable. During austral winter, vocalizations were recorded at latitudes as high as 69°S, with sea ice cover exceeding 90%, suggesting that some Antarctic blue whales overwinter in Antarctic waters. Polynyas likely serve as an important habitat for baleen whales during austral winter, providing food and reliable access to open water for breathing. Overall, our results support increasing evidence of a complex and non-obligatory migratory behavior of Antarctic blue whales, potentially involving temporally and spatially dynamic migration routes and destinations, as well as variable timing of migration to and from the feeding grounds.

Diel and seasonal patterns in acoustic presence and foraging behaviour of free-ranging harbour porpoises

A temporal and geographical analysis of echolocation activity can give insights into the behaviour of free-ranging harbour porpoises Phocoena phocoena. Seasonal and diel patterns in the presence and foraging activity of harbour porpoises were investigated based on a year-long passive acoustic monitoring data set recorded at 5 sites in the western Baltic Sea. Diel patterns in detection rates were found at 4 sites. A year-round rhythm in presence, however, was found at only 1 station, whereas the other 3 stations showed diel rhythms for 2 to 3 seasons. Three of the sites showed diel patterns in foraging sequences on a seasonal level, but no station showed such patterns for the complete year of investigation. Both diurnal and nocturnal patterns in harbour porpoise detections were observed, indicating that diel rhythmic behaviour is more complex than previously reported. In contrast, foraging behaviour showed only nocturnal rhythms. Owing to the limitations in passive acoustic monitoring, all categorized foraging sequences are a minimum esti- mate. Therefore, classified foraging sequences are most likely pelagic foraging, while bottom grubbing could have been missed. Differences in the occurrence of foraging sequences between station, season and time of day lead to the assumption that the long-term echolocation diel pat- terns of porpoises strongly depend on the temporal changes in food availability and composition within a certain habitat. Echolocation behaviour of foraging porpoises is strongly influenced by seasonally available prey resources, which require adaptive foraging strategies. Therefore, owing to seasonal variations, analyses of diel patterns need to be conducted over sufficiently long time periods and large geographic scales to allow generalized interpretation of the findings. Conse- quently, no general conclusion regarding diel rhythms in harbour porpoise echolocation was found. We hypothesize that porpoises in the study area alternate between foraging on benthic prey in shallow waters at daytime and in the pelagic in deeper waters at night.

Exploring habitat selection in sea snakes using passive acoustic monitoring and Bayesian hierarchical models

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 546:249-262 (2016) - DOI: https://doi.org/10.3354/meps11632 Exploring habitat selection in sea snakes using passive acoustic monitoring and Bayesian hierarchical models V. Udyawer1,*, C. A. Simpfendorfer1, M. Read2, M. Hamann1, M. R. Heupel1,3 1Centre for Sustainable Tropical Fisheries and Aquaculture & College of Marine and Environmental Sciences, James Cook University, Townsville, Queensland 4811, Australia 2Great Barrier Reef Marine Park Authority, PO Box 1379, Townsville, Queensland 4810, Australia 3Australian Institute of Marine Science, Townsville, Queensland 4810, Australia *Corresponding author: vinay.udyawer@my.jcu.edu.au ABSTRACT: Resource selection studies often use analytical techniques that provide information at either a population or an individual level. We applied a Bayesian hierarchical model that simultaneously estimates population- and individual-level habitat selection to explore how varying levels of dietary specialisation affect resource requirements of 2 species of sea snakes that occupy the same coastal environment. We used passive acoustic telemetry to monitor the movements of the 2 species—a dietary generalist, Hydrophis (Lapemis) curtus, and a dietary specialist, H. elegans—and investigated how individuals select habitats based on habitat type, depth and proximity to sources of freshwater within a nearshore environment. Composition of diets in both species was also assessed using regurgitated material from captured individuals. Selection of habitats by the 2 species differed, with H. elegans displaying an affinity for mudflat and seagrass habitats <4 km from sources of freshwater and depths <3 m. H. curtus selected for slightly deeper seagrass habitats (1-4 m) further from freshwater sources (2-5 km). Data from regurgitated material showed that the diet of H. curtus comprised at least 4 families of fish and displayed some level of intraspecific predation, whereas H. elegans preyed solely on eels. Both species predominantly selected seagrass areas, indicating that these habitats provide key resources for sea snakes within nearshore environments. The results illustrated the utility of Bayesian hierarchical models when analysing passive acoustic monitoring data to provide population-level habitat selection metrics and incorporate individual-level variability in selection, both of which are necessary to inform targeted management and conservation practices. KEY WORDS: Acoustic telemetry · Coastal habitat · Hydrophis (Lapemis) curtus · Hydrophis elegans · Resource selection · Dietary specialisation Full text in pdf format PreviousNextCite this article as: Udyawer V, Simpfendorfer CA, Read M, Hamann M, Heupel MR (2016) Exploring habitat selection in sea snakes using passive acoustic monitoring and Bayesian hierarchical models. Mar Ecol Prog Ser 546:249-262. https://doi.org/10.3354/meps11632 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 546. Online publication date: March 21, 2016 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2016 Inter-Research.

Ghosts in the data: false detections in VEMCO pulse position modulation acoustic telemetry monitoring equipment

False-positive data (better known as “false detections”) in VEMCO VR2 acoustic telemetry monitoring studies that use pulse position modulation coding can cause biased or erroneous outcomes in data analysis. To understand the occurrence of false detections in acoustic monitoring data sets, the results of a range test experiment using eight acoustic receivers and 12 transmitters were examined. One hundred and fifty one tag ID codes were recorded, 137 of which were identified as likely from false detections, 12 were from test tags, and two were from tagged sharks. False detections accounted for <0.05 % of detections (918) in the experiment. False detection tag ID codes were not randomly distributed amongst the available codes, being more likely to occur at IDs close to tags used in the experiment. Receivers located near the bottom recorded the most false detections and tag ID codes from false detections. Receivers at the same depth did not differ significantly in the mean number of daily false detections. The daily number of false detections recorded by a receiver did not conform to a random pattern, and was not strongly correlated with daily receiver performance. In an era of increasing data sharing and public storage of scientific data, the occurrence of false detections is of significant concern and the results of this study demonstrate that while rare they do occur and can be identified and accounted for in analyses.

Passive acoustic monitoring of beaked whale densities in the Gulf of Mexico.

Beaked whales are deep diving elusive animals, difficult to census with conventional visual surveys. Methods are presented for the density estimation of beaked whales, using passive acoustic monitoring data collected at sites in the Gulf of Mexico (GOM) from the period during and following the Deepwater Horizon oil spill (2010–2013). Beaked whale species detected include: Gervais’ (Mesoplodon europaeus), Cuvier’s (Ziphius cavirostris), Blainville’s (Mesoplodon densirostris) and an unknown species of Mesoplodon sp. (designated as Beaked Whale Gulf — BWG). For Gervais’ and Cuvier’s beaked whales, we estimated weekly animal density using two methods, one based on the number of echolocation clicks, and another based on the detection of animal groups during 5 min time-bins. Density estimates derived from these two methods were in good general agreement. At two sites in the western GOM, Gervais’ beaked whales were present throughout the monitoring period, but Cuvier’s beaked whales were present only seasonally, with periods of low density during the summer and higher density in the winter. At an eastern GOM site, both Gervais’ and Cuvier’s beaked whales had a high density throughout the monitoring period.

Statistical mechanics techniques applied to the analysis of humpback whale inter-call intervals

Techniques developed in statistical mechanics recently have been applied to the analysis of the topology of complex human communication networks. These methods examine the network's macroscopic statistical properties rather than the details of individual interactions. Here, these methods are applied to the analysis of the time intervals between humpback whale calls detected in passive acoustic monitoring data collected by the bottom-mounted hydrophones on the Pacific Missile Range Facility (PMRF) west of Kauai, Hawaii. Recently developed localization and tracking algorithms for use with PMRF data have been applied to separate the calls of an individual animal from those of a collection of animals. As with the distributions of time intervals between human communications, the distributions of time intervals between humpback whale call detections are distinctly different than those expected for a purely independent, random (Poisson) process. This conclusion holds both for time intervals between calls from individual animals and from the collection of animals vocalizing simultaneously. although significant differences in these probability distributions occur. A model based on the migration of clusters of animals is developed to fit the distributions. Possible mechanisms giving rise to aspects of the distributions are discussed. [Work supported by the Office of Naval Research, Code 322-MMB.]

Acoustic monitoring of migratory birds over western Lake Erie: avian responses to barriers and the importance of islands

Understanding the flight patterns of migrating birds is critical for informing conservation actions and management decisions. We studied the geographic and temporal distribution of birds migrating through the southern Great Lakes using nocturnal acoustic monitoring data and banding records from sites on Pelee Island in Lake Erie and on the mainland along the north shore of Lake Erie. Given that Lake Erie may represent an ecological barrier to migratory birds, we predicted that mainland and island sites would show different patterns in both the number of passage migrants and the timing of their migration. Analysis of over 60,000 flight calls from 6200 h of recordings revealed significantly more migrants over the island than the mainland in both spring and fall 2012. The acoustic data provide evidence that none of the species or species groups examined avoided crossing the lake. Birds were detected significantly earlier on Pelee Island than on the north shore of Lake Erie in spring, although they were not detected earlier on the mainland in fall. These results suggest that Lake Erie is not a major barrier to migration. The large number of birds detected over the island suggest that birds may concentrate their flight over islands in the middle of the lake, although recordings of migrants over open water will be required to support this suggestion. Our results show that Pelee Island is an important part of the migratory route of North American birds and provide valuable information on the movement of nocturnal migrants over the Great Lakes.

New Method of Active Electromagnetic Induction and Seismic Monitoring in Oil Saturated Media

It is provided a comparison of no equilibrium effects by independent hydro dynamical and electromagnetic induction influence on an oil layer and the medium, which it surrounds. It is known, that by drainage and steeps the hysteresis effect on curves of the relative phase permeability in dependence from porous medium water saturation by some cycles of influence: drainage-steep-drainage is observed. In earlier papers the analysis of the seism acoustic monitoring data in regimes of phone radiation, response on the first influence of given frequency and on the second influence is developed. For the analysis of seism acoustic response in time on fixed intervals along the borehole an algorithm of phase diagrams of the state of many phase medium is suggested. On the base of developed algorithm a new algorithm of analyze of space, but integral in time for equal observation periods changing by the method of phase diagram state of many phase medium in the oil layer is developed. The developed method allows on quality level to classify the state of the polyphase medium, which is the oil layer, using data of many cycles influence. In that paper we suggest the algorithm of modeling of 2-d seismic field distribution in the heterogeneous medium with hierarchic inclusions. Using the developed earlier 3-d method of induction electromagnetic frequency geometric monitoring we showed the opportunity of defining of physical and structural features of hierarchic oil layer structure and estimating of water saturating by crack inclusions. That allows managing the process of drainage and steeping by water displacement the oil out of the layer. Thus, the developed methods allow on the quality and quantity levels to make a classification of the many phase medium, which is an oil layer, using data for multiple excitation. For quantitative solution of earlier listed events of no equilibrium and hysteretic interaction of water and oil by out working of the oil layer, it is urgently to add and to further develop the system of seism acoustic and electromagnetic observations.

Integration of passive acoustic monitoring data into OBIS-SEAMAP, a global biogeographic database, to advance spatially-explicit ecological assessments

We successfully developed an extension of the OBIS-SEAMAP database, a global biogeographic database specializing in marine mammals, seabirds and sea turtles, to integrate passive acoustic monitoring (PAM) data with other commonly collected data types (i.e. line-transect visual sightings, animal telemetry, and photo-identification). As part of this effort, we made significant improvements in mapping and visualization tools for PAM data, including spatially and temporally interactive summary statistics, diel plots, temporal effort representation, and the unique rendering of PAM data to distinguish them from other data types. In this paper, we summarize technical challenges we overcame, report the methodologies and implementation of the integration, and conduct case studies using visual sightings and PAM data from bowhead whales and Risso's dolphins to demonstrate how the integrated database facilitates in-depth ecological assessments that form the foundation for spatially-explicit conservation efforts.