@article{ricci_bohnenstiehl_2022, title={Monitoring visitation at North Carolina artificial reef sites using high spatiotemporal resolution PlanetScope imagery}, volume={55}, ISSN={["2352-4855"]}, url={http://dx.doi.org/10.1016/j.rsma.2022.102511}, DOI={10.1016/j.rsma.2022.102511}, abstractNote={Historically, the recreational use of reefs has been assessed through on-water observations, which often provide limited spatiotemporal coverage, and boater interviews, which may have low response rates. To overcome these limitations, an object detection model was trained and deployed to identify small boats within high resolution (∼3 m/pixel) PlanetScope imagery at four North Carolina offshore artificial reefs during 2019. The resulting visitation time series consisted of 1319 stationary and 201 underway vessels detections. This is ∼12 times the number of visitations reported during 2019 from the Marine Recreational Information Program (MRIP) boat-ramp interviews and ∼20 times the number captured using Automatic Identification System (AIS) vessel-tracking data. Although the MRIP surveys do not report any visitations during the winter months, imagery-based detections show that the use of these reefs extends throughout the winter. Detections also show steady use of the sites on weekends, whereas the MRIP interviews indicate relatively fewer visitors on Sundays. Imagery-based detections and MRIP results show AR-315 to be the most visited reef. However, whereas the MRIP results indicate limited use of the other sites, the imagery-based visitation shows that AR-370 and AR-425 reefs are visited nearly as often, with AR-160 being under-utilized relative to these sites. These comparisons show how the low survey response rate and sparsity of tracking beacons on small vessels may lead to a biased assessment of visitation patterns. The clustering of detections within sites highlights the relative popularity of different reef materials among users. Leveraging the growing availability of high spatiotemporal resolution satellite imagery, this automated framework can be used to detect boats around other areas and times of interest. Visitation information is essential in assessing the socioeconomic impacts of these reefs, and important in the design and maintenance of current and future reefs to support local coastal economies and recreation.}, journal={REGIONAL STUDIES IN MARINE SCIENCE}, publisher={Elsevier BV}, author={Ricci, Shannon W. and Bohnenstiehl, DelWayne R.}, year={2022}, month={Sep} }
 @article{lyon_eggleston_bohnenstiehl_layman_ricci_allgeier_2019, title={Fish community structure, habitat complexity, and soundscape characteristics of patch reefs in a tropical, back-reef system}, volume={609}, ISSN={["1616-1599"]}, url={http://dx.doi.org/10.3354/meps12829}, DOI={10.3354/meps12829}, abstractNote={Fig. S1. Box plots for nightly low frequency (0.1 – 1.5 kHz) SPL (a) and high frequency (4 – 20 kHz) SPL (b) for reef 5 for each lunar quarter. Red lines indicate median SPLs, ticks indicate maximum and minimum values, horizontal blue lines indicate 75% and 25% quantiles, and angled blue lines indicate the 95% upper and lower confidence levels in the median. Kruskal-Wallis tests were used to test for differences in SPL between lunar quarters. Relationships between water temperature (in C) and low frequency (0.1 – 1.5 kHz) SPL (c) and high frequency (4 – 20 kHz) SPL (d) were evaluated using linear regression models. 2 = 2.52 p = 0.47}, journal={MARINE ECOLOGY PROGRESS SERIES}, publisher={Inter-Research Science Center}, author={Lyon, R. Patrick and Eggleston, David B. and Bohnenstiehl, DelWayne R. and Layman, Craig A. and Ricci, Shannon W. and Allgeier, Jacob E.}, year={2019}, month={Jan}, pages={33–48} }
 @article{bohnenstiehl_lyon_caretti_ricci_eggleston_2018, title={Investigating the utility of ecoacoustic metrics in marine soundscapes}, volume={2}, url={http://dx.doi.org/10.22261/jea.r1156l}, DOI={10.22261/jea.r1156l}, abstractNote={Soundscape analysis is a potentially powerful tool in ecosystem monitoring. Ecoacoustic metrics, including the Acoustic Complexity Index (ACI) and Acoustic Entropy (H), were originally developed for terrestrial ecosystems and are now increasingly being applied to investigate the biodiversity, habitat complexity and health of marine systems, with mixed results. To elucidate the efficacy of applying these metrics to marine soundscapes, their sensitivity to variations in call rate and call type were evaluated using a combination of field data and synthetic recordings. In soundscapes dominated by impulsive broadband snapping shrimp sounds, ACI increased nonlinearly with increased snapping rate (∼100–3500 snaps/min), with a percent range of variation (∼40–50%) that exceeds that reported in most studies. H, however, decreased only slightly (∼0.04 units) in response to these same snap rate changes. The response of these metrics to changes in the rate of broadband snapping was not strongly influenced by the spectral resolution of the analysis. For soundscapes dominated by harmonic fish calls, increased rates of calling (∼5–120 calls/min) led to decreased ACI (∼20–40% range of variation) when coarse spectral resolutions (Δf = 94 or 47 Hz) were used in the analysis, but ACI increased (∼20% range of variation) when a finer resolution (Δf = 23 Hz) was employed. Regardless of spectral resolution used in the analysis, H decreased (∼0.20 units) in response to increased rates of harmonic calling. These results show that ACI and H can be modulated strongly by variations in the activity of a single sound-producing species, with additional sensitivity to call type and the resolution of the analysis. Variations in ACI and H, therefore, cannot be assumed to track call diversity, and the utility of these metrics as ecological indicators in marine environments may be limited.}, number={2}, journal={Journal of Ecoacoustics}, publisher={MDPI AG}, author={Bohnenstiehl, DelWayne R. and Lyon, R. Patrick and Caretti, Olivia N. and Ricci, Shannon W. and Eggleston, David B.}, year={2018}, month={Sep}, pages={1–1} }
 @article{ricci_bohnenstiehl_eggleston_kellogg_lyon_2017, title={Oyster toadfish (Opsanus tau) boatwhistle call detection and patterns within a large-scale oyster restoration site}, volume={12}, ISSN={["1932-6203"]}, url={http://dx.doi.org/10.1371/journal.pone.0182757}, DOI={10.1371/journal.pone.0182757}, abstractNote={During May 2015, passive acoustic recorders were deployed at eight subtidal oyster reefs within Harris Creek Oyster Sanctuary in Chesapeake Bay, Maryland USA. These sites were selected to represent both restored and unrestored habitats having a range of oyster densities. Throughout the survey, the soundscape within Harris Creek was dominated by the boatwhistle calls of the oyster toadfish, Opsanus tau. A novel, multi-kernel spectral correlation approach was developed to automatically detect these boatwhistle calls using their two lowest harmonic bands. The results provided quantitative information on how call rate and call frequency varied in space and time. Toadfish boatwhistle fundamental frequency ranged from 140 Hz to 260 Hz and was well correlated (r = 0.94) with changes in water temperature, with the fundamental frequency increasing by ~11 Hz for every 1°C increase in temperature. The boatwhistle call rate increased from just a few calls per minute at the start of monitoring on May 7th to ~100 calls/min on May 10th and remained elevated throughout the survey. As male toadfish are known to generate boatwhistles to attract mates, this rapid increase in call rate was interpreted to mark the onset of spring spawning behavior. Call rate was not modulated by water temperature, but showed a consistent diurnal pattern, with a sharp decrease in rate just before sunrise and a peak just after sunset. There was a significant difference in call rate between restored and unrestored reefs, with restored sites having nearly twice the call rate as unrestored sites. This work highlights the benefits of using automated detection techniques that provide quantitative information on species-specific call characteristics and patterns. This type of non-invasive acoustic monitoring provides long-term, semi-continuous information on animal behavior and abundance, and operates effectively in settings that are otherwise difficult to sample.}, number={8}, journal={PLOS ONE}, publisher={Public Library of Science (PLoS)}, author={Ricci, Shannon W. and Bohnenstiehl, DelWayne R. and Eggleston, David B. and Kellogg, M. Lisa and Lyon, R. Patrick}, editor={Li, SonghaiEditor}, year={2017}, month={Aug} }
 @article{ricci_eggleston_bohnenstiehl_2017, title={Use of passive acoustic monitoring to characterize fish spawning behavior and habitat use within a complex mosaic of estuarine habitats}, volume={93}, ISSN={["1553-6955"]}, url={http://dx.doi.org/10.5343/bms.2016.1037}, DOI={10.5343/bms.2016.1037}, abstractNote={Structurally complex estuarine habitats, such as seagrass beds, salt marshes, and oyster reefs, are used by fish for foraging, avoiding predators, and spawning. Here, we used passive acoustics to characterize spatiotemporal patterns in the soundscape of an estuarine reserve that contained a mosaic of habitat types, and focused on relating characteristics of the soundscape [e.g., low-frequency (150–1500 Hz) sound pressure levels (SPLs), amount of fish chorusing] to patterns in the seascape (percent cover of estuarine habitats surrounding the recording sites). Over a 3-mo period, 2-min duration underwater sound recordings were made every 20 min at eight sites within Middle Marsh in Back Sound, North Carolina, USA. While habitat composition was not related to spatial patterns in low-frequency SPLs, there was a positive and statistically significant relationship between the percent recordings with fish chorusing, and percent cover of seagrass for silver perch [Bairdiella chrysoura (Lacepede, 1802)], spotted seatrout [Cynoscion nebulosus (Cuvier, 1830)], and other fish, irrespective of spatial scale (10 vs 25 m). Moreover, silver perch and spotted seatrout, soniferous species that share similar spawning locations, exhibited temporal partitioning in the soundscape with seatrout calls occurring just before sunset and peaking several hours after sunset, and declining sharply as perch chorusing increased after sunset with a peak at midnight. Overall, local habitat composition and the soundscape at these sites were not highly correlated; where major sound producing fish species are transient, other seascape characteristics, such as proximity to channels, likely have a larger influence on the resulting soundscape.}, number={2}, journal={BULLETIN OF MARINE SCIENCE}, publisher={Bulletin of Marine Science}, author={Ricci, Shannon W. and Eggleston, David B. and Bohnenstiehl, DelWayne R.}, year={2017}, month={Apr}, pages={439–453} }
 @article{ricci_eggleston_bohnenstiehl_lillis_2016, title={Temporal soundscape patterns and processes in an estuarine reserve}, volume={550}, ISSN={["1616-1599"]}, url={http://dx.doi.org/10.3354/meps11724}, DOI={10.3354/meps11724}, abstractNote={: Underwater acoustic recordings can be used to measure the distribution and activity of sound-producing species and investigate variability in the physical and biological characteristics of marine ecosystems. This study characterized the summer soundscape of a coastal estuarine reserve, Middle Marsh, near Beaufort Inlet, North Carolina, USA. Passive recorders were de ployed at 8 sites, within a mixture of seagrass, saltmarsh, oyster reef and soft-bottom habitats, and sampled for 2 min every 20 min between June and August 2014. Sound pressure levels (SPLs) in a high-frequency band (7−43 kHz) exhibited a periodicity of once per day, being 11 dB higher during the nighttime. This pattern is correlated with snapping shrimp sounds, with an average excess of ~12% more snaps detected at night. The same analysis for SPLs in a low-frequency band (150−1500 Hz) revealed a periodicity of twice per day, with diurnal sound levels varying by up to 29 dB. Temporal variability in the low-frequency soundscape is correlated with fish chorusing, as well as tidal water level, which may influence both the presence and absence of fish and the propagation of sound in the water column. The greatest SPLs are observed in association with periods of high biological activity during nighttime high tides. Sampling marine animals and their activities over ecologically relevant time scales is challenging using conventional techniques (trawls and throw traps) within complex shallow water habitats, particularly at night. Soundscape monitoring provides an additional method to assess spatiotemporal variation in essential fish habitat use within a complex mosaic of habitat types.}, journal={MARINE ECOLOGY PROGRESS SERIES}, publisher={Inter-Research Science Center}, author={Ricci, Shannon W. and Eggleston, David B. and Bohnenstiehl, DelWayne R. and Lillis, Ashlee}, year={2016}, month={May}, pages={25–38} }