scholarly journals Drifting hydrophones as an ecologically meaningful approach to underwater soundscape measurement in coastal benthic habitats

2018 ◽  
Vol 2 (1) ◽  
pp. 1-1 ◽  
Author(s):  
Ashlee Lillis ◽  
Francesco Caruso ◽  
T. Aran Mooney ◽  
Joel Llopiz ◽  
DelWayne Bohnenstiehl ◽  
...  

The ambient acoustic environment, or soundscape, is of broad interest in the study of marine ecosystems as both a source of rich sensory information to marine organisms and, more broadly, as a driver of the structure and function of marine communities. Increasing our understanding of how soundscapes affect and reflect ecological processes first requires appropriate characterization of the acoustic stimuli, and their patterns in space and time. Here, we present a novel method developed for measuring soundscape variation, using drifting acoustic recorders to quantify acoustic dynamics related to benthic habitat composition. Selected examples of drifter results from sub-tidal oyster-reef habitats in Pamlico Sound, North Carolina, USA, and from coral reef habitats in St. John, US Virgin Islands, highlight the efficacy and utility of this approach in quantifying soundscape variation in diverse habitats. The platform introduces minimal noise into the acoustic recordings, and allows sampling at spatial scales that might typically be overlooked using stationary hydrophone methods. We demonstrate that mobile hydrophone recording methods offer new insight into soundscape variation and provide a complementary approach to conventional passive acoustic monitoring techniques.

2020 ◽  
Vol 653 ◽  
pp. 131-151
Author(s):  
JJ Suca ◽  
A Lillis ◽  
IT Jones ◽  
MB Kaplan ◽  
AR Solow ◽  
...  

Understanding the cues that drive larval fish settlement is critical for managing reef systems under stress. Reef sound is increasingly reported to influence fish recruitment, yet the physical and acoustic environment in which larval fish settle varies in space and time. Accordingly, testing potential settlement cues under different conditions is vital for understanding their ecological importance. We conducted 2 sets of field playback experiments in St. John, US Virgin Islands, one nearshore (10 m depth) and the second ‘offshore’ (25 m depth), to assess the effects of reef soundscape playback on settlement rates of multiple reef fish families. In each experiment, nightly currents were quantified and we replicated the diel soundscape cycle using high, low, and control (silent) amplitude recordings from nearby reefs. The first experiment revealed significant current-based, down-stream reduction in larval fish catches in subsurface light traps and a significant effect of increasing amplitude of reef playbacks on larval lizardfish (Synodontidae) catches. In the second, offshore experiment which had no current effect, increasing reef playback amplitude led to a significantly greater catch of parrotfish (Scaridae) larvae and decreased larval pelagic fish catch. Total reef fish larvae only showed attraction to reef playbacks at the most nearshore site. This work demonstrates that while sound can play a role in the settlement of certain reef fishes, responses are influenced by multiple factors, including larger-scale physical processes, underscoring the need to consider the scale of soundscape cues for reef fish settlement within an oceanographic context.


2018 ◽  
Vol 69 (7) ◽  
pp. 1026 ◽  
Author(s):  
Renee E. Bartolo ◽  
Andrew J. Harford ◽  
Chris L. Humphrey ◽  
Amy K. George ◽  
Rick A. van Dam

Key ecological processes must be present and maintained in ecosystems to ensure the success of ecological restoration and conservation programs. The present paper identifies and defines key ecological processes operating at various spatial scales within aquatic ecosystems of the Magela Creek catchment, within Kakadu National Park, and prioritises those that may be vulnerable to potential mine-derived stressors. This assessment was required to ensure that current and future environmental monitoring programs are in place to safeguard the protection of these processes, particularly in the context of rehabilitation of Ranger uranium mine. Ecological processes within riparian habitats and biotic interactions across all habitats were at a higher risk of exposure to potential stressors. Generally, the selected assessment endpoints used for the operational phase of the mine are sufficient to measure and assess ecological processes. However, biological endpoints require additional suitable early detection indicators because marked lags exist in their response, which will be more important during the rehabilitation phase of the mine because of the longer timeframes to be assessed. The lags would otherwise allow potential impacts to underpinning processes to pass undetected. Risk identification allows monitoring programs to move beyond simple measurement variables to full evaluation of underlying ecological processes, which maintain both structure and function in ecosystems.


2018 ◽  
Vol 81 (2) ◽  
pp. 109-124 ◽  
Author(s):  
JL Pinckney ◽  
C Tomas ◽  
DI Greenfield ◽  
K Reale-Munroe ◽  
B Castillo ◽  
...  

2021 ◽  
Vol 6 (2) ◽  
pp. 66
Author(s):  
S. Grace Prakalapakorn ◽  
Lucas Bonafede ◽  
Linda Lawrence ◽  
Daniel Lattin ◽  
Nicola Kim ◽  
...  

Among children born with laboratory-confirmed Zika virus (ZIKV) infection, visual impairment (VI) can occur despite normal ocular structure. The objective of this report is to describe ocular findings and visual function among children examined during the Department of Health Zika Health Brigade (ZHB) in the United States Virgin Islands in March 2018. This analysis is based on a retrospective chart review of children eligible to participate in the ZHB (i.e., part of the US Zika Pregnancy and Infant Registry) and who were examined by ophthalmologists. Eighty-eight children attended the ZHB. This report includes 81 children [48 (59.3%) males] whose charts were located [average gestational age = 37.6 weeks (range: 27.6–41.3) and average adjusted age at examination = 9.1 months (range: 0.9–21.9)]. Of those examined, 5/81 (6.2%) had microcephaly at birth, 2/81 (2.5%) had a structural eye abnormality, and 19/72 (26.4%) had VI. Among children with normal ocular structure and neurologic examination, 13/51 (25.5%) had VI. Despite a low incidence of abnormal ocular structure and microcephaly, about a quarter of children examined had VI. Our findings emphasize that ophthalmological examinations should be performed in all children with suspicion for antenatal ZIKV infection, even children with normal ocular structure and neurologic examination.


Toxins ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 413
Author(s):  
Justin D. Liefer ◽  
Mindy L. Richlen ◽  
Tyler B. Smith ◽  
Jennifer L. DeBose ◽  
Yixiao Xu ◽  
...  

Ciguatera poisoning (CP) poses a significant threat to ecosystem services and fishery resources in coastal communities. The CP-causative ciguatoxins (CTXs) are produced by benthic dinoflagellates including Gambierdiscus and Fukuyoa spp., and enter reef food webs via grazing on macroalgal substrates. In this study, we report on a 3-year monthly time series in St. Thomas, US Virgin Islands where Gambierdiscus spp. abundance and Caribbean-CTX toxicity in benthic samples were compared to key environmental factors, including temperature, salinity, nutrients, benthic cover, and physical data. We found that peak Gambierdiscus abundance occurred in summer while CTX-specific toxicity peaked in cooler months (Feb–May) when the mean water temperatures were approximately 26–28 °C. These trends were most evident at deeper offshore sites where macroalgal cover was highest year-round. Other environmental parameters were not correlated with the CTX variability observed over time. The asynchrony between Gambierdiscus spp. abundance and toxicity reflects potential differences in toxin cell quotas among Gambierdiscus species with concomitant variability in their abundances throughout the year. These results have significant implications for monitoring and management of benthic harmful algal blooms and highlights potential seasonal and highly-localized pulses in reef toxin loads that may be transferred to higher trophic levels.


Diversity ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 234 ◽  
Author(s):  
Eric A. Griffin ◽  
Joshua G. Harrison ◽  
Melissa K. McCormick ◽  
Karin T. Burghardt ◽  
John D. Parker

Although decades of research have typically demonstrated a positive correlation between biodiversity of primary producers and associated trophic levels, the ecological drivers of this association are poorly understood. Recent evidence suggests that the plant microbiome, or the fungi and bacteria found on and inside plant hosts, may be cryptic yet important drivers of important processes, including primary production and trophic interactions. Here, using high-throughput sequencing, we characterized foliar fungal community diversity, composition, and function from 15 broadleaved tree species (N = 545) in a recently established, large-scale temperate tree diversity experiment using over 17,000 seedlings. Specifically, we tested whether increases in tree richness and phylogenetic diversity would increase fungal endophyte diversity (the “Diversity Begets Diversity” hypothesis), as well as alter community composition (the “Tree Diversity–Endophyte Community” hypothesis) and function (the “Tree Diversity–Endophyte Function” hypothesis) at different spatial scales. We demonstrated that increasing tree richness and phylogenetic diversity decreased fungal species and functional guild richness and diversity, including pathogens, saprotrophs, and parasites, within the first three years of a forest diversity experiment. These patterns were consistent at the neighborhood and tree plot scale. Our results suggest that fungal endophytes, unlike other trophic levels (e.g., herbivores as well as epiphytic bacteria), respond negatively to increasing plant diversity.


2015 ◽  
Vol 3 ◽  
pp. 242-255 ◽  
Author(s):  
Katherine E. Wirt ◽  
Pamela Hallock ◽  
David Palandro ◽  
Kathleen Semon Lunz

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