James Locascio

Diel Periodicity of Fish Sound Production in Charlotte Harbor, Florida

Abstract Diel periodicity in sound production of estuarine fishes was documented in Charlotte Harbor, Florida, from 7 May to 10 June 2003. A long-term acoustic recording system was used to record 10 s of sound every 10 min within the frequency range of 0-1,250 Hz. Diel patterns in fish sound production were well defined throughout the study period. Chorusing events dominated by sand seatrout Cynoscion arenarius reached a mean daily (24-h period) maximum sound pressure level of 117 dB relative to a reference effective pressure of 1 μPa. Mean daily chorus start and end times were 1726 and 0210 hours Eastern Standard Time, respectively, and chorus events lasted an average of 8.7 h. Other species recorded on most nights included the Gulf toadfish Opsanus beta, spotted seatrout C. nebulosus, and silver perch Bairdiella chrysoura. The results from this study demonstrate how this technology can be scaled to examine spawning soniferous fishes across large spatial and temporal scales.

Sound Production and Reproductive Behavior of Yellowfin Grouper, Mycteroperca venenosa (Serranidae) at a Spawning Aggregation

Reproductive behaviors and sound production of the Yellowfin grouper (Mycteroperca venenosa) are described from in-situ observations by divers as well as synchronous underwater audio-video recordings at a spawning aggregation off Mona Island, Puerto Rico. The highest abundances of M. venenosa estimated from underwater visual surveys were detected in March and April, five to nine days after the full moon (DAFM). Four distinct color phases were observed for M. venenosa; two of these were unique to the spawning aggregation and one, the white-headed phase, was exhibited during interactions with other conspecifics corresponding to courtship displays. Variations in color phases during fish interactions and group formation coupled with sounds preceded spawning, which occurred near sunset. Low-frequency (<150 Hz) sounds produced by M. venenosa were variable yet they were classified into two types, pulsed and tonal. Both types of sounds were associated with reproductive behaviors although not linked to spawning rushes. These sounds were most frequent between 1800 and 2100 h, peaked the eighth DAFM, and ceased between 11–13 DAFM. Temporal patterns in sound production suggest that peak reproduction occurred in April followed by a smaller aggregation in May of 2010. The association of passive acoustics with reproductive behaviors for M. venenosa provides a tool to help identify spawning aggregation sites and monitor spawning stock abundance to evaluate the effectiveness of management and conservation efforts for this Near Threatened grouper.

Localization and source level estimates of black drum (Pogonias cromis) calls

A four hydrophone linear array was used to localize calling black drum and estimate source levels and signal propagation. A total of 1025 source level estimates averaged 165 dB(RMS) relative (re:) 1 μPa (standard deviation (SD)=1.0). The authors suggest that the diverticulated morphology of the black drum swimbladder increase the bladders surface area, thus contributing to sound amplitude. Call energy was greatest in the fundamental frequency (94 Hz) followed by the second (188 Hz) and third harmonics (282 Hz). A square root model best described propagation of the entire call, and separately the fundamental frequency and second harmonic. A logarithmic model best described propagation of the third harmonic which was the only component to satisfy the cut-off frequency equation. Peak auditory sensitivity was 300 Hz at a 94 dB re: 1 μPa threshold based on auditory evoked potential measurements of a single black drum. Based on mean RMS source level, signal propagation, background levels, and hearing sensitivity, the communication range of black drum was estimated at 33-108 m and was limited by background levels not auditory sensitivity. This estimate assumed the source and receiver were at approximately 0.5 m above the bottom. Consecutive calls of an individual fish localized over 59 min demonstrated a mean calling period of 3.6 s (SD=0.48), mean swimming speed of 0.5 body lengths/s, and a total distance swam of 1035 m.

ACOUSTIC COMMUNICATION IN FISHES

To study sound production in fishes, a variety of techniques are used, including hydrophones connected to recorders on the surface (e.g., Breder 1967), self-contained underwater recorders (e.g., Locascio & Mann 2005), and coupled underwater video and hydrophones (e.g., Lobel & Mann 1995). Coupled audio-video recordings can be used to identify sounds associated with specific behaviours. Long-term recordings with self-contained recorders can be used to infer diel and longer term behavioural patterns.

Sound production and spawning by black brum (Pogonias cromis) in southwest Florida

We used the Long Term Acoustic Recording System (LARS) to investigate patterns of sound production in spawning aggregations of black drum (Pogonias cromis) during 2004 ‐ 2006 in southwest Florida. Our purposes were to document trends in black drum sound production on daily and seasonal time scales and to investigate the temporal and quantitative relationships between egg production and sound production. Sound production was strongly diel, beginning near dusk and lasting for several hours. Sound production occurred from October through April and peaked in February‐March, consistent with prior descriptions of the spawning season for this species based on the gonado‐somatic index (GSI). To investigate the relationship between sound production and egg production, surface plankton tows were conducted hourly between 1600 ‐ 0400 on two consecutive nights while continuous underwater acoustic recordings were made. This was done five times between January and April, 2006. Neither the timing nor quantity of sound pr...

Diel periodicity of fish sound production in Charlotte Harbor, Florida

Diel periodicity in sound production of spawning aggregations of fishes was documented in Charlotte Harbor, Florida from 7 May 2003–10 June 2003. The Long Term Acoustic Recording System (LARS) recorded 10 s of sound every 10 min within the frequency range of 0–1250 Hz. Field data collected in this study revealed diel patterns in fish sound production in great detail. Autocorrelation results demonstrated pronounced diel periodicity in fish sound production with significant lags occurring at 24‐h periods. Chorusing events dominated by sand seatrout, Cynoscion arenarius, lasted for several hours each night and were not highly variable in duration, maximum recorded SPL, or start and end times. Mean daily (24‐h period) maximum sound‐pressure level was 119 decibels, mean daily chorus start time was 17:26 h Eastern Standard Time, mean daily chorus end time was 02:10 h Eastern Standard Time, and the average nightly chorus duration lasted 8 h and 43 min.

Passive acoustic detection of grouper sound production

Passive acoustic recordings were used to study the behavior of red hind (Epinephelus guttatus) at spawning aggregation sites off of Puerto Rico and Mona Island, and goliath grouper (Epinephelus itajara) and red grouper (Epinephelus morio) on the West Florida Shelf. The sounds produced by each species were unique, low‐frequency pulsed sounds and associated with reproductive‐related behavior. Male red hind produced sounds composed of a series of pulses that graded into a tonal‐like sound, mostly during territorial patrolling. Long‐term acoustic recorder (LARS) data from the west coast of Puerto Rico and Mona Island showed similar diel periodicities of sound production of red hind, but had different monthly peaks in sound production. Goliath grouper sounds consisted of low‐frequency individual pulses (50‐100 Hz) that are consistent with sounds produced by a large fish, and showed lunar periodicity in sound production. Peaks in sound production occurred nightly after midnight, but sounds were also produced throughout the day. Sound production and spawning by red grouper was recorded using a remotely operated vehicle (ROV) at depths of 80‐100 m. Passive acoustic techniques can provide synoptic, long‐term time series of sound production associated with reproductive activities of soniferous species at widely spaced sites.

Listening in the Ocean: New Discoveries and Insights on Marine Life from Autonomous Passive Acoustic Recorders

Passive acoustics provides a near perfect ocean observatory sensor for biological activity in fishes. For species whose sounds have been documented, we can use passive acoustic recording to learn about their ecology. In this chapter we review the history of the development of passive acoustics research on fishes. Today, fish passive acoustic monitoring is in a rapid stage of development as an additional tool for fisheries research. The latest studies have focused on temporal and spatial patterns of sound production of fishes, including many commercially important species such as groupers and cods. These studies have been conducted with long-term fixed passive acoustic recorders and more recently with gliders and other autonomous platforms. These methods are complementary, as long-term recorders provide excellent temporal coverage and gliders provide excellent spatial coverage. The greatest impediment to further advance is that for most fishes we still do not know what sounds they make. We suggest that miniature acoustic tags may be one way to increase our library of known fish sounds. The main challenges remaining are the development of tools to automatically analyze large datasets, and experimental studies to enable quantification of fish numbers and spawning using passive acoustics.

Chorusing in fishes

Many fishes in the family Sciaenidae engage in nightly chorusing events where sound production starts near dusk and lasts for several hours. This paper examines the periodicity and dynamics of chorusing in the Sciaenidae. Underwater acoustic recorders have been deployed in southwest Florida to record sound production with a high temporal resolution (10 s of recording every 10 min) over a large spatial area. Sound production was dominated by three sciaenid species: silver perch (Bairdiella chyrsoura), sand seatrout (Cynoscion arenarius), and spotted seatrout (Cynoscion nebulosus). Sounds produced by black drum (Pogonias cromis), gafftopsail catfish (Bagre marinus), and gulf toadfish (Opsanus beta) were also recorded. Sound levels in sciaenid choruses typically reach levels of approximately 110–120 dB re 1 μPa spectrum level, and are among the loudest sources of sustained ambient noise in temperate and subtropical coastal waters. Little is known about the behavior accompanying sound production, because it o...