Sanchez et al.: Patterns of courtship acoustics and spawning sites of Mycteroperca bonad 
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Time (s) 
Figure 2 
Examples of (A) strong and (B) weak spectrograms of courtship- 
associated sounds (CASs) made by black grouper {Mycteroperca 
bonaci) and collected by a digital spectrogram recorder at Bajo 
de Sico, Puerto Rico, in 2013. Presence of pulse train undulation 
specific to black grouper within the frequency band of 75-100 Hz 
is visually detectable in both spectrograms. The x-axis is time in 
seconds. The y-axis is frequency in hertz. Brightness of yellow color 
indicates increased strength of CAS call. 
The calendar day with a rising full moon (local time) 
was considered day 0. Each successive day was consid¬ 
ered another DAFM, until the next day of a rising full 
moon. Daily total numbers of CASs during periods of 
increased courtship calling were broken down into hour 
blocks. Hourly totals during these periods of increased 
activity were summed over the entire analysis period 
to examine daily patterns. 
For each site, analysis of variation was done with 
Fisher’s least significant difference test to determine 
differences between daily numbers of CASs for DAFM 
and hourly numbers of CASs for periods of increased 
activity. 
Temperature 
Temperature loggers (HOBO Water Temp Pro v2, Onset 
Computer Corp., Bourne, MA) were deployed at Mona 
Island and Bajo de Sico from 3 January to 31 April 
2014. Temperature data from Mona Island was record¬ 
ed at a spawning aggregation of red hind, nearby the 
spawning aggregation of black grouper, at a depth of 30 
m. Temperature data from Bajo de Sico was recorded 
at the site of a DSG recorder, nearby the spawning ag¬ 
gregation of black grouper, at a depth of 45 m. 
Site geophysical features 
Geophysical features of the sites were analyzed by 
using the methods from Kobara and Heyman (2008). 
Analysis was done in ArcGIS 10.3 (Esri, Redlands, CA) 
with the Spatial Analyst and 3D toolboxes. For the 
morphometric analysis, the specific location 
of each DSG recorder that supplied data 
used in acoustics analysis was considered 
the location of the FSA. That point loca¬ 
tion was overlaid on high-resolution multi¬ 
beam bathymetry maps for Bajo de Sico and 
Mona Island (Battista^). A 1-km-radius buf¬ 
fer around the location of the recorder was 
isolated from the bathymetry map. Depth 
was converted to slope and slope was ex¬ 
tracted into contours. Slope contours were 
superimposed on depth. The “shelf edge” 
was classified as the continuous 20°-slope 
contour at a steep vertical depth profile off 
the shallower structure. The structure out¬ 
lined within the 1-km buffer area was used 
to visually identify promontories along the 
shelf edge. A promontory was defined as a 
noticeable convex protrusion extending off 
the contour of the shelf edge within the 
1-km-radius scale. 
The morphometric parameters measured 
were the shortest distances from the FSA 
to 1) the shelf edge, 2) the 30-m depth con¬ 
tour, and 3) the horizontal inflection point 
defining the nearest promontory feature. 
The depth of the shelf edge was measured 
at its nearest point to the FSA location. The 
aggregation of black grouper at Riley’s Hump was not 
analyzed through bathymetric data; but the above pa¬ 
rameters were read from an existing bathymetric map 
from Locascio and Burton (2016), originally published 
in Mallinson et al. (2003). 
Results 
Temporal analysis 
Mona Island Mean daily CAS rates peaked in Febru¬ 
ary for all 3 years, from 2012 through 2014, at Mona 
Island. Production of CASs increased between the last 
quarter moon and the new moon, from 8 to 14 DAFM 
(Table 2). Production of CASs increased between 8 and 
12 DAFM (Fig. 3). CASs were correlated strongly with 
time of day (Table 3). During the 3 seasons at Mona 
Island, 54% of all recorded CASs by black grouper oc¬ 
curred during a 2-h period between 1700 and 1900 h 
local time (Fig. 4). The 4-h period between 1600 and 
2000 h, 16% of the day, contained 68% of the total num¬ 
ber of CASs produced (Fig. 4). 
2 Battista, T. 2015. Water depth and acoustic backscat- 
ter data collected from NOAA Ship Nancy Foster in Carib¬ 
bean Sea, southern coast of Isla de Mona, western coast of 
Puerto Rico from 2007-04-14 to 2007-04-24 (NCEI Accession 
0131853). Version 1.1. NOAA National Centers for Environ¬ 
mental Information, Silver Spring, MD. [Data set available 
from website.] 
