Papers by Agnieszka Monczak
Aquatic Mammals
The Charleston Harbor in South Carolina (SC)is a major port that experiences high levels of vesse... more The Charleston Harbor in South Carolina (SC)is a major port that experiences high levels of vessel traffic. Historical analyses of coastal bottlenose dolphin (Tursiops truncatus, now Tursiops erebennus) sightings identified multiple core use areas in the harbor that overlap with these anthropogenic activities. Informed by these long-term spatial data, passive acoustic monitoring, visual surveys, and prey sampling were conducted from December 2017 to June 2019 to assess the relationships and multivariate interactions that may influence dolphin vocalization patterns. Vocalizations varied spatially and temporally, peaking in fall and winter months coinciding with decreases in water temperature and daylight hours, following patterns previously reported in other SC estuaries. Dolphin prey and total fish abundance decreased with water temperature, which may indicate that dolphins echolocate and whistle more frequently in the winter months when prey are scarce and sound-producing species a...
Black drum Pogonias cromis, red drum Sciaenops ocellatus, silver perch Bairdiella chrysoura, and ... more Black drum Pogonias cromis, red drum Sciaenops ocellatus, silver perch Bairdiella chrysoura, and spotted seatrout Cynoscion nebulosus belong to the family Sciaenidae and are commonly found in South Carolina (USA) estuaries. Fish within this family produce sounds that are associated with courtship behavior and spawning. By listening to estuarine soundscapes, we can identify spawning aggregations. In this study, our objectives were to investigate longterm patterns of black drum, silver perch, spotted seatrout, and red drum calling and chorusing (i.e. indicative of spawning) over a 6 yr time span; identify any shifts in seasonal sound production from one year to the next; and examine the relationship between chorusing and young-of-the-year (YOY) abundance collected through haul seines. We found that in years with warmer springs, black drum, silver perch, and spotted seatrout began chorusing earlier and had longer chorusing seasons than in the years with cooler temperatures. Inversely, cooler temperatures during late summer led to earlier and longer spawning seasons for red drum. We detected the appearance of YOY in the estuary approximately 1 mo after initiation of the chorusing season. Silver perch were the most abundant in the spring, spotted seatrout during the summer, and red drum during the fall. Additionally, we found positive correlations between chorusing and YOY abundance. In years with longer chorusing seasons, we detected higher abundance of silver perch, spotted seatrout, and red drum YOY than in the years with shorter chorusing periods. These patterns provide supporting evidence that passive acoustics can aid in monitoring reproductive output of an estuary. OPEN PEN ACCESS CCESS Passive acoustic recorders and seining were used to investigate long-term patterns of fish courtship sounds and their relationship to young-of-the-year appearance and abundance
In the Southeast USA, major contributors to estuarine soundscapes are the courtship calls produce... more In the Southeast USA, major contributors to estuarine soundscapes are the courtship calls produced by fish species belonging to the family Sciaenidae. Long-term monitoring of sciaenid courtship sounds may be valuable in understanding reproductive phenology, but this approach produces massive acoustic datasets. With this in mind, we designed a feature-based, signal detector for sciaenid fish calls and tested the efficacy of this detector against manually reviewed data. Acoustic recorders were deployed to collect sound samples for 2 min every 20 min at four stations in the May River estuary, South Carolina, USA from February to November, 2014. Manual analysis of acoustic files revealed that four fish species, belonging to the family Sciaenidae, were the major sound producers in this estuarine soundscape, and included black drum (Pogonias cromis), silver perch (Bairdiella chrysoura), spotted seatrout (Cynoscion nebulosus), and red drum (Sciaenops ocellatus). Recorded calls served as an acoustic library of signature features that were used to create a signal detector to automatically detect, classify, and quantify the number of calls in each acoustic file. Correlation between manual and automatic detection was significant and precision varied from 61% to 100%. Automatic detection provided quantitative data on calling rates for this long-term data set. Positive temperature anomalies increased calling rates of black drum, silver perch, and spotted seatrout, while negative anomalies increased calling rates of red drum. Acoustic monitoring combined with automatic detection could be an additional or alternative method for monitoring sciaenid spawning and changes in phenology associated with climate change.
The impact of boat related noise on marine life is a subject of concern, particularly for fish sp... more The impact of boat related noise on marine life is a subject of concern, particularly for fish species that utilize acoustic communication for spawning purposes. The goal of this study was to quantify and examine the risk of boat noise on fish acoustic communication by performing acoustic monitoring of the May River, South Carolina (USA) from February to November 2013 using DSG-Ocean recorders. The number of boats detected increased from the source to the mouth with the highest detections near the Intracoastal Waterway (ICW). Boat noise frequency ranges overlapped with courtship sounds of silver perch (Bairdiella chrysoura), black drum (Pogonias cromis), oyster toadfish (Opsanus tau), spotted seatrout (Cynoscion nebulosus), and red drum (Sciaenops ocellatus). In the May River estuary, red drum may experience the greatest risk of auditory masking because of late afternoon choruses (21% time overlap with boat noise) and only one spawning location near the noisy ICW.
In this study, our goal was to perform
acoustic monitoring of the May River, South Carolina
(USA)... more In this study, our goal was to perform
acoustic monitoring of the May River, South Carolina
(USA), for a 9 mo period and estimate reproductive
timelines for a community of soniferous fishes.
Acoustic recorders were deployed to collect sound
samples for 2 min, every 20 min at 4 stations from the
source to the mouth from February to November
2013. We detected the acoustic presence of 6 fish
species: Atlantic croaker Micropogonias undulatus,
black drum Pogonias cromis, silver perch Bairdiella
chrysoura, oyster toadfish Opsanus tau, spotted sea -
trout Cynoscion nebulosus, and red drum Sciaenops
ocellatus. Acoustic detection rates and diversity of
soniferous fish were higher near the mouth and de -
creased towards the source, suggesting a selection of
deeper water and/or more stable water quality conditions
for spawning. We estimated the start and end
dates of the spawning season and calculated the total
hours of chorusing for silver perch, oyster toadfish,
spotted seatrout, and red drum. Each species followed
a specific seasonal and daily pattern of calling,
and we observed synchrony of these calling patterns
among stations. For silver perch, oyster toadfish,
black drum, and spotted seatrout, a negative tem -
perature anomaly correlated with decreased calling
intensity, while a positive anomaly increased sound
production. For oyster toadfish and spotted seatrout,
the lunar phase significantly influenced calling.
These data serve as a foundation for future studies
that are investigating how climate variability may
affect seasonal spawning timelines and year class
strength of fish populations using passive acoustic
monitoring.
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Papers by Agnieszka Monczak
acoustic monitoring of the May River, South Carolina
(USA), for a 9 mo period and estimate reproductive
timelines for a community of soniferous fishes.
Acoustic recorders were deployed to collect sound
samples for 2 min, every 20 min at 4 stations from the
source to the mouth from February to November
2013. We detected the acoustic presence of 6 fish
species: Atlantic croaker Micropogonias undulatus,
black drum Pogonias cromis, silver perch Bairdiella
chrysoura, oyster toadfish Opsanus tau, spotted sea -
trout Cynoscion nebulosus, and red drum Sciaenops
ocellatus. Acoustic detection rates and diversity of
soniferous fish were higher near the mouth and de -
creased towards the source, suggesting a selection of
deeper water and/or more stable water quality conditions
for spawning. We estimated the start and end
dates of the spawning season and calculated the total
hours of chorusing for silver perch, oyster toadfish,
spotted seatrout, and red drum. Each species followed
a specific seasonal and daily pattern of calling,
and we observed synchrony of these calling patterns
among stations. For silver perch, oyster toadfish,
black drum, and spotted seatrout, a negative tem -
perature anomaly correlated with decreased calling
intensity, while a positive anomaly increased sound
production. For oyster toadfish and spotted seatrout,
the lunar phase significantly influenced calling.
These data serve as a foundation for future studies
that are investigating how climate variability may
affect seasonal spawning timelines and year class
strength of fish populations using passive acoustic
monitoring.
acoustic monitoring of the May River, South Carolina
(USA), for a 9 mo period and estimate reproductive
timelines for a community of soniferous fishes.
Acoustic recorders were deployed to collect sound
samples for 2 min, every 20 min at 4 stations from the
source to the mouth from February to November
2013. We detected the acoustic presence of 6 fish
species: Atlantic croaker Micropogonias undulatus,
black drum Pogonias cromis, silver perch Bairdiella
chrysoura, oyster toadfish Opsanus tau, spotted sea -
trout Cynoscion nebulosus, and red drum Sciaenops
ocellatus. Acoustic detection rates and diversity of
soniferous fish were higher near the mouth and de -
creased towards the source, suggesting a selection of
deeper water and/or more stable water quality conditions
for spawning. We estimated the start and end
dates of the spawning season and calculated the total
hours of chorusing for silver perch, oyster toadfish,
spotted seatrout, and red drum. Each species followed
a specific seasonal and daily pattern of calling,
and we observed synchrony of these calling patterns
among stations. For silver perch, oyster toadfish,
black drum, and spotted seatrout, a negative tem -
perature anomaly correlated with decreased calling
intensity, while a positive anomaly increased sound
production. For oyster toadfish and spotted seatrout,
the lunar phase significantly influenced calling.
These data serve as a foundation for future studies
that are investigating how climate variability may
affect seasonal spawning timelines and year class
strength of fish populations using passive acoustic
monitoring.