Table of Contents

• Coverage
• Dataset Description
  • Methods & Sampling
  • Data Processing Description
  • BCO-DMO Processing Description
• Data Files
• Related Publications
• Parameters
• Instruments
• Deployments
• Project Information
• Funding

This dataset contains passive acoustic recordings from a mid-latitude oyster reef in Pamlico Sound, North Carolina, USA. Each file contains raw acoustic records collected using a DSG hydrophone recorder (Loggerhead Instruments) deployed near the center of West Bay Marine Reserve between June 2011 and July 2012. The hydrophone was configured to record 60 or 30 seconds of data every 15 or 30 minutes (depending on the deployment duration). The sample rate for each deployment was 50,000 Hz.

Related References:

Additional information about this dataset can be found in:

Bohnenstiehl, D.R., Lillis, A., & Eggleston, D.B. (2016). The Curious Acoustic Behavior of Estuarine Snapping Shrimp: Temporal Patterns of Snapping Shrimp Sound in Sub-Tidal Oyster Reef Habitat. PLOS ONE 11(1): e0143691. https://doi.org/10.1371/journal.pone.0143691

Beginning in June of 2011, a long-term effort was initiated to record ambient underwater sound within the West Bay Marine Reserve. This was accomplished using a low-power DSG acoustic recorder (Loggerhead Instruments, Sarasota, FL, USA) equipped with an off-the-shelf HTI-96 hydrophone with a sensitivity of -185.8 dBV/μPa and flat frequency response between ~0.1 and 30 kHz (High-Tech Inc., Gulfport Mississippi). The instrument was powered by a set of standard alkaline D-cell batteries. The data were digitized using a 16-bit resolution and written to a standard solid-state SD memory card. All components are housed in a 0.65 m long, 11.5 cm diameter PVC pressure case.

The instrument was deployed near the center of the West Bay Marine Reserve at a depth of ~3 m below MLLW and on an area of flat lying seabed ~10 m from surrounding oyster reef habitat. The pressure case was mounted vertically using a concrete anchor to position the hydrophone element ~1 m off the seabed. The tidal range within West Bay is small, typically <0.75 m.

A total of eight deployments were carried out using a single DSG recorder between 18 June 2011 and 06 July 2012. The resulting time series includes data collected on a total of 321 days over this 384-day monitoring period, which represents an 83% data return rate. Depending on the planned length of the deployment, the instrument was programmed to record for a 60 sec duration at 15-minute intervals, or for a duration of 30 sec at 30-minute intervals. A 50-kHz sampling rate was used for all deployments. The usable bandwidth of the data is taken to be ~0.1-20.0 kHz, as the DSG applies an anti-alias filter prior to A/D conversion. In total, 27,565 separate recordings were made as part of this monitoring initiative.

The data may be read into MATLAB using the included function DSGread.m (from Loggerhead Instruments).

Example:
% Set calibration and gain
hydro_cal=-185.8;
DSG_gain=10; % or 20

% Load DSG file
% DF_HEAD and SID_SPEC are structures with file information
% (e.g. record date and time)
% datacat are data strung together and scaled to +/-1 by MATLAB
[DF_HEAD,SID_SPEC,totrecs,datacat]=DSGread(FileName,0,0);

% convert to uPa
VoltsPeruPa=power(10,(hydro_cal+DSG_gain)/20);
datacat=datacat/VoltsPeruPa;

% plot
srate=1000000/(SID_SPEC.SP256/256);
t=[0:length(datacat)-1]/srate; %create time scale
figure(1)
plot(t,datacat);
xlabel('Time (s)');
ylabel('Sound Level (uPa)');

% Calculate rms SPL (dB re 1uPa)
rmsdB=20*log10(std((datacat-mean(datacat)))) %calculate dB re 1uP

No processing. These are the raw data files in DSG format.

Version 1 (date: 2015-12-09):
- Added conventional header with dataset name, PI name, version date.
- Renamed parameters to BCO-DMO standard.
- Created flat file with submitted metadata including lat and lon, date/time, recording parameters, and links to download the data files.
- Calculated ISO_TimeDate_Local_start and _end.

Version 2 (Date: 2024-02-16):
- Replaced the 'file_link' field with 'file_name' in the CSV data file.
- Attached the 8 .zip files as data files.

The overall goal of this study is to advance our general understanding of the role of underwater sound in biological oceanography by characterizing spatiotemporal variation in an estuarine soundscape, and determine if this variation affects the settlement of larval invertebrates. The investigators will use larval bivalves and subtidal oyster reefs in Pamlico Sound, North Carolina as a study system. A combination of field and laboratory experiments will be used to test the effects of sound on larval behaviors and settlement. The underwater sonic environment has the potential to provide meaningful sensory information to all aquatic animals. Acoustic signals are transmitted relatively large distances, are present at all depths, and reflect biological and physical characteristics of the environment, while other cues (e.g. light, chemicals) are rapidly attenuated from the source. Sound is well established as an orientation and habitat selection cue for marine mammals and fishes, and has recently emerged as a potentially important contributor to larval settlement. Building capacity (knowledge, expertise, equipment) for integrating geophysical aspects of underwater sound propagation with ecological and oceanographic processes is central to bio-physical studies of larval connectivity and recruitment in marine systems. It also informs our understanding of the potential adverse effects of noise pollution in the ocean and may elucidate untested benefits of marine reserves - ultimately leading to healthier and better managed oceans and estuaries. The project supports graduate, postdoctoral and undergraduate student training, as well as educational outreach programs that span local, regional and national levels