190 
Fishery Bulletin 115(2) 
Table 2 
Results of analysis of variance tests comparing the dependent variable mean 
number of courtship-associated sounds per day against the independent vari¬ 
able days after full moon for this study of acoustic courtship of black grouper 
(Mycteroperca bonaci) during 2012-2014 at Riley’s Hump (RH) off southern 
Florida and at Mona Island (MI) and Bajo de Sico (BDS). iV=total number of 
days recorded. df=degrees freedom. MS=means squared. 
Site and year 
N 
df 
MS 
F 
P-value 
RH 2012 
149 
29 
5.43 
3.89 
<0.0001 
MI 2012 
120 
29 
12.43 
4.38 
<0.0001 
MI 2013 
119 
29 
21.59 
3.98 
<0.0001 
MI 2014 
120 
29 
22.33 
3.93 
<0.0001 
BDS 2013 
119 
29 
4.74 
2.06 
<0.0001 
BDS 2014 
120 
29 
7.47 
1.81 
0.0178 
Table 3 
Results of analysis of variance tests comparing the dependent variable mean 
hourly numbers of courtship-associated sounds against the independent vari¬ 
able hour of day for this study of acoustic courtship of black grouper (Mycte¬ 
roperca bonaci) during 2012-2014 at Riley’s Hump (RH) off southern Florida 
and at Mona Island (MI) and Bajo de Sico (BDS). iV=hours of day (24)xnum- 
ber of months analyzed. df=degrees freedom. MS=mean square. 
Site and year 
N 
df 
MS 
F 
P-value 
RH 2012 
144 
23 
6.78 
6.99 
<0.0001 
MI 2012 
120 
23 
37.84 
19.83 
<0.0001 
MI 2013 
120 
23 
79.59 
31.79 
<0.0001 
MI 2014 
120 
23 
80.93 
13.77 
<0.0001 
BDS 2013 
120 
23 
2.78 
2.34 
0.0034 
BDS 2014 
120 
23 
9.21 
4.68 
<0.0001 
Temperature 
Temperature time-series data for 
2014 indicated decreasing tempera¬ 
tures from January to March (Fig. 
5). In March, temperatures remained 
near annual minimums before be¬ 
ginning to increase in April. At both 
Bajo de Sico and Mona Island, tem¬ 
peratures dropped below 27°C from 
mid-January to mid-April. Tempera¬ 
tures remained slightly lower at 
Bajo de Sico than at Mona Island 
but only by tenths of a degree Cel¬ 
sius, potentially a result of deploy¬ 
ment of the temperature logger at a 
depth of 45 m at Bajo de Sico com¬ 
pared with deployment at a depth of 
30 m at Mona Island. 
Site geophysical features 
All 3 spawning sites fell within the 
geophysical parameters described 
for multispecies FSAs in the Cay¬ 
man Islands and Belize (Table 4). 
The Bajo de Sico and Mona Island 
spawning sites were less than 100 m 
from convex promontories, less than 
100 m from the shelf edge, and in an 
area where the shelf edge is found 
at depths of 25-30 m. Similar geo¬ 
physical parameters were evident 
at Riley’s Hump. This site was situ¬ 
ated at a depth of approximately 35 
m and was adjacent to deep water 
(>100 m). All 3 sites were within 500 
m of a 30-m vertical wall. 
Riley's Hump The daily mean number of CASs peaked 
in April at Riley’s Hump in 2012, increasing 2-fold 
from the month of lowest activity, February. Produc¬ 
tion of CASs increased from 7 to 11 DAFM, and peaked 
at 10 DAFM (Fig. 3). Daily production of CASs was 
correlated strongly with time of day (Table 3). Of all 
CASs at Riley’s Hump, 35% occurred in a 2-h window 
from 1600 to 1800 h local time. Almost half (48%) of all 
CASs occurred from 1500 to 1900 h local time (Fig. 4). 
Bajo de Sico At Bajo de Sico, CAS counts were sub¬ 
stantially lower than counts recorded at Mona Island 
and Riley’s Hump. Daily mean number of CASs peaked 
in January. Production of CASs increased from 4 to 10 
DAFM (Fig. 3) in 2013; however, no defined peak pe¬ 
riod was evident. In 2014, peaks were more defined. 
Production of CASs increased 6-9 DAFM (Fig. 3). Sim¬ 
ilar variation in hourly numbers of CASs was found 
between the 2 years at Bajo de Sico. Hour was deter¬ 
mined to be significant (Table 3) for both years; how¬ 
ever, patterns were more evident in 2014 (Fig. 4). 
Discussion 
The 3 spawning aggregations of black grouper had 
comparable patterns in their CAS production (Figs. 3 
and 4) and site geophysical features (Table 4). Selected j 
sites exhibited definable geophysical parameters that ; 
can be used to identify undocumented FSAs. In addi- ! 
tion, distinct, well-defined, comparable patterns in CAS ' 
production were observed at 2 of the 3 FSAs analyzed 
in this study. Patterns of sound production at Mona Is¬ 
land were very similar over the 3 years. Seasonal tim¬ 
ing of CAS production at Mona Island had little inter- ; 
annual variability, when examined in relation to DAFM j 
and time of day, and was similar to temporal patterns 
observed at Riley’s Hump. Elevated periods of CASs 
production at Riley’s Hump were observed monthly 
during December-April, except January. 
At Bajo de Sico, CAS temporal patterns varied be¬ 
tween the 2 seasons during which passive acoustic re¬ 
cordings were collected. In 2013, there were periods of 
