Dataset: Original recordings of reef soundscapes and recordings of playbacks from coral reefs in St. John, U.S. Virgin Islands collected between 2013 to 2017

Experiment 1 Original Reef Recordings:  Continuous recordings of Tektite and Ramhead reefs in August 2013 Pa
Experiment 1 Playback Experiment:  Recordings Recordings of playbacks from experiment 1 in 2016 for each site in each night
Experiment 2 Original Reef Recordings: Continuous recordings of Tektite and Booby Rock reefs in summer 2017
Experiment 2 Playback Experiment Recordings: Recordings of playbacks from experiment 2 in 2017 for each site in each nightFull Methods can be found in Suca et al. (2020). The following descriptions are exercpts from the methods of this paper.

Units in these data are Pa.

Experiment 1 Original Reef Recordings: Natural reef soundscape treatments were randomly selected 24 h periods from a 4 d continuous recording of 2 nearby reefs, Tektite (18.310° N, 64.722° W) and Ram Head (18.301° N, 64.704° W) (see Fig. 1 in Suca et al., 2020). Initial recordings were made in August 2013 using a 120 kHz sampling rate and 50 kHz low-pass filter, and were down-sampled to 48 kHz for this experiment.

Experiment 1 Playback Experiment Recordings: The reef soundscape recordings were amplified using Adobe Audition (Adobe Systems) to ensure broadband SPLrms were similar to the original reef recordings. At the initiation of a given trial, the playback recordings were started at the time of day matching the start time of the experiment. This allowed the playback recordings to match the diel cycle, including the crepuscular fish chorus, of the local coral reefs. High and low sound level treatments were manipulated through the volume settings on the audio players such that the full-band SPLrms (0.1−20 kHz) of the high and low treatments were approximately 120 and 115 dB re 1 µPa, respectively. Because decibels are logarithmic, this 5 dB difference is equivalent to one treatment being about twice the amplitude of the other in terms of sound pressure. A silent file was played on loop as the silent control treatment to account for potential effects of the electromagnetic field generated by the playback equipment. Locations of treatments (high, low, and silent) were randomly selected each night to minimize confounding spatial effects on settlement.

Experiment 2 Original Reef Recordings: Soundscape playback treatments consisted of natural reef soundscapes, recorded continuously for 24 h from 1−4 nights prior to each trial. This allowed us to closely match season and lunar phase of fish settlement (unlike Expt 1), as reef soundscapes are known to vary (though weakly) at these temporal scales. Recordings were made using a SoundTrap ST300 with a 48 kHz sampling rate, at 2 reefs, both with high coral cover and fish abundance relative to other reefs in the region (Booby Rock, 18.302° N, 64.710° W; Tektite, 18.310° N, 64.722° W) maximizing the likelihood of elevated SPLrms in frequencies below 3000 Hz. While it is unlikely that most fish hear the high frequencies of snapping shrimp, it is worth noting that these reefs had similar SPLrms in the snapping shrimp acoustic band (which generally have greatest acoustic energy above 2000 Hz). Five continuous recordings of reef sounds were collected and used for playbacks.

Experiment 2 Playback Experiment Recordings: A hydrophone (SoundTrap ST300, Ocean Instruments) was attached to the bottom of each light trap and recorded at a sampling rate of 48 kHz for 63 s every 5 min to acquire sufficient recordings of playbacks while maximizing the efficiency of data processing. The playback experiment was conducted for 13 nights, with 10 nights occurring in July and 3 in August. Five continuous recordings of reef sounds were collected and used for playbacks. Three of these recordings were collected at Tektite reef and 2 at Booby Rock reef. Most recordings were used for less than 3 playbacks, except for 20−23 July when the same recording was used for 4 experiments due to time constraints precluding the collection and processing of an additional continuous recording. Overall, this randomization of multiple acoustic treatments sought to reduce pseudoreplication of sound stimuli and more closely replicate natural soundscapes from reefs with abundant fish sounds. The continuous recordings of reef soundscapes were amplified and initiated, and treatments (high, low, silent) were assigned in the same manner as Expt 1.

Instruments: 
Experiment 1: DMON; Woods Hole Oceanographic Institution; flat frequency response from 100 Hz to 50 kHz and total design sensitivity of −167 dB re V/µPa

Experiment 2: SoundTrap ST300; Ocean Instruments; ST8 = -171.3 dB re V/µPa; ST10 = -171.9 dB re V/µPa; ST4 = -171.2 dB re V/µP