Carrie C. Wall

Trouble-shooting deployment and recovery options for various stationary passive acoustic monitoring devices in both shallow- and deep-water applications.

Deployment of any type of measuring device into the ocean, whether to shallow or deeper depths, is accompanied by the hope that this equipment and associated data will be recovered. The ocean is harsh on gear. Salt water corrodes. Currents, tides, surge, storms, and winds collaborate to increase the severity of the conditions that monitoring devices will endure. All ocean-related research has encountered the situations described in this paper. In collating the details of various deployment and recovery scenarios related to stationary passive acoustic monitoring use in the ocean, it is the intent of this paper to share trouble-shooting successes and failures to guide future work with this gear to monitor marine mammal, fish, and ambient (biologic and anthropogenic) sounds in the ocean-in both coastal and open waters.

Quantification of Boat Visitation Rates at Artificial and Natural Reefs in the Eastern Gulf of Mexico Using Acoustic Recorders

Artificial reefs are commonly used as a management tool, in part to provide ecosystem services, including opportunities for recreational fishing and diving. Quantifying the use of artificial reefs by recreational boaters is essential for determining their value as ecosystem services. In this study, four artificial–natural reef pairs in the eastern Gulf of Mexico (off western Florida) were investigated for boat visitation rates using autonomous acoustic recorders. Digital SpectroGram (DSG) recorders were used to collect sound files from April 2013 to March 2015. An automatic detection algorithm was used to identify boat noise in individual files using the harmonic peaks generated by boat engines, and by comparing the sound amplitude of each file with surrounding files. In all four pairs, visitation rates were significantly higher at the artificial reef than the natural reef. This increase in boat visitation was likely due to actual or perceived increased quality of fishing and diving at the artificial reefs, or to lack of knowledge of the presence or locations of the natural reefs. Inshore reefs (<15 m depth) had high variability in monthly visitation rates, which were generally highest in warmer months. However the seasonal signal was dampened on offshore reefs (>25 m depth). This study appears to be the first to use acoustic data to measure participant use of boating destinations, and highlights the utility of acoustic monitoring for the valuation of this important ecosystem service provided by artificial reefs.

Fish Sound Production in the Presence of Harmful Algal Blooms in the Eastern Gulf of Mexico

This paper presents the first known research to examine sound production by fishes during harmful algal blooms (HABs). Most fish sound production is species-specific and repetitive, enabling passive acoustic monitoring to identify the distribution and behavior of soniferous species. Autonomous gliders that collect passive acoustic data and environmental data concurrently can be used to establish the oceanographic conditions surrounding sound-producing organisms. Three passive acoustic glider missions were conducted off west-central Florida in October 2011, and September and October 2012. The deployment period for two missions was dictated by the presence of red tide events with the glider path specifically set to encounter toxic Karenia brevis blooms (a.k.a red tides). Oceanographic conditions measured by the glider were significantly correlated to the variation in sounds from six known or suspected species of fish across the three missions with depth consistently being the most significant factor. At the time and space scales of this study, there was no detectable effect of red tide on sound production. Sounds were still recorded within red tide-affected waters from species with overlapping depth ranges. These results suggest that the fishes studied here did not alter their sound production nor migrate out of red tide-affected areas. Although these results are preliminary because of the limited measurements, the data and methods presented here provide a proof of principle and could serve as protocol for future studies on the effects of algal blooms on the behavior of soniferous fishes. To fully capture the effects of episodic events, we suggest that stationary or vertically profiling acoustic recorders and environmental sampling be used as a complement to glider measurements.

The benefits and challenges of passive acoustic monitoring of fish

While is it widely known that numerous families of fish produce sound for communication, discerning when, where, and who is more difficult. Recent developments in passive acoustic technologies have facilitated marine bioacoustic studies to effectively monitor soniferous fishes. Because acoustic data can be collected over a wide range of habitats and depth for long periods of time, passive acoustic monitoring can map and monitor marine species to efficiently provide year-round information on distribution. This presentation reviews data recorded using moored passive acoustic arrays and hydrophone-integrated gliders. Low frequency (50–6000 Hz) sounds recorded by these methods provide a better understanding of the diurnal and spatial distribution of known fish calls (e.g., red grouper). However, this is seemingly overwhelmed by the vast number of sounds produced by unknown species. Instrument and anthropogenic noise, managing the large of amounts of data collected, and identifying the source of previously und...

Large scale passive acoustic data management.

Passive acoustic recording systems can generate large amounts of data, especially given the increasing capability of inexpensive flash memory. DSGLab, an open‐source database and data analysis system implemented with MATLAB and a portal to MYSQL, was created to handle large amounts of raw data collected by dozens of acoustic recorders over periods up to a year. Each recorded data file is tagged with header information including latitude, longitude, depth or altitude, timestamp, sample rate, and calibration, among other metadata variables, and uploaded to the database. This information allows all files in the database to be queried based on, for example, location (latitude, longitude, depth) and time (date, hour). Then the data analysis section processes the desired selection of files according to a user‐specified signal processing chain, which does not require prior programming knowledge, and returns the results to a database and to individual files. The signal processing results can then be quickly brows...

Leveraging big data: How acoustic archives facilitate ecosystem research

The National Oceanic and Atmospheric Administration’s (NOAA) National Centers for Environmental Information (NCEI) has developed archives for the long-term stewardship of active and passive acoustic data. Water column sonar data have been collected for fisheries and habitat characterization over large spatial and temporal scales around the world, and archived at NCEI since 2013. Protocols for archiving passive acoustic data are currently being established in support of the NOAA Ocean Noise Reference Station Network project, and monitoring marine mammals and fish. Archives maintain data, but access to these data is a core mission of NCEI that allows users to discover, query, and analyze the data in new and innovative ways. Visualization products continue to be developed and integrated into the data access portal so that researchers of varying backgrounds can easily understand the quality and content of these complex data. Spatially and temporally contemporary oceanographic and bathymetric data are also lin...

Global access to sonar data: Where can it take you?

Scientific echosounders aboard NOAA fishery survey vessels are used to estimate biomass, measure fish school morphology, and characterize habitat. These surveys produce large volumes of data that are stored locally and difficult to access. Data that are easily discoverable and accessible provide valuable information beyond their original collection purpose. NOAA’s National Centers for Environmental Information, in partnership with the National Marine Fisheries Service and the University of Colorado, created a national archive for the stewardship and distribution of water column sonar data. A data access web page allows users to query the metadata and access the raw sonar data. Visualization products allow researchers and the public to understand the quality and content of large volumes of archived data. Such products transform the complex raw data into a digestible image and are highly valuable for a broad audience of varying backgrounds. Concurrently collected oceanographic and bathymetric data are being...

Shelf-scale mapping of fish sound production with ocean gliders

Ocean gliders are a powerful platform for collecting large-scale data on the distribution of sound-producing animals while also collecting environmental data that may influence their distribution. Since 2009, we have performed extensive mapping on the West Florida Shelf with ocean gliders equipped with passive acoustic recorders. These missions have revealed the distribution of red grouper as well as identified several unknown sounds likely produced by fishes. In March 2014, we ran a mission along the shelf edge from Cape Canaveral, FL to North Carolina to map fish sound production. The Gulf Stream and its strong currents necessitated a team effort with ocean modeling to guide the glider successfully to two marine protected areas. This mission also revealed large distributions of unknown sounds, especially on the shallower portions of the shelf. Gliders provide valuable spatial coverage, but because they are moving and most fish have strong diurnal sound production patterns, data analysis on presence and ...

Getting more for less: Increasing the accessibility of water column sonar data for fisheries management

Active acoustic technology is of increasing importance for studies examining fish populations and biological abundance in the water column. Multibeam echosounders are employed routinely on NOAA fishery vessels to estimate biomass, conduct trophic- and species-level identification, measure school morphology and behavior, and characterize habitat for commercially important species. These surveys deliver valuable information for ecosystem-based fisheries management but they also produce massive amounts of data that are costly and difficult to maintain. With its ability to store and preserve large datasets, NOAAs National Geophysical Data Center is acquiring and archiving acoustic data collected from NOAA and academic fleets. Through these efforts, an accessible archive of acoustic water column data will be made available to researchers and the public around the world. A web-based search engine will allow anyone to identify where data were collected, what instrument was used, and access the raw data and asso...

Long-term mapping of red grouper sound production on the West Florida Shelf

While it is widely known that numerous fish species produce sound, discerning when and where is more challenging. Through the use of autonomous passive acoustic technology, the spatial and temporal patterns of fish sound production, namely red grouper Epinephelus morio, in the eastern Gulf of Mexico were documented. Two methods have been employed off west-central Florida: moored passive acoustic arrays deployed in 2008 and 2009 covering over 16 600 km2 from the coast to 100 m deep, and autonomous gliders with integrated hydrophones deployed cross-shelf for up to 4weeks. Over four million acoustic files generated from these methods were analyzed using DSGLab, an open-source database and data analysis system implemented using Matlab and MySQL. An automatic detection algorithm was created and implemented in DSGLab to determine the presence of red grouper calls. False detections were removed manually and the results were analyzed to determine diel and seasonal variability of red grouper sound production in ad...