Stoner et a\. : Recruitment of Strombus gigas 
889 
ing lateral spines) of crabs was measured, carapace 
length for shrimps, and shell length of gastropods. 
Data analysis 
To discern station differences, density data from the 
dredge sampling were log-transformed (log 10 (n+1)) 
to improve homogeneity of variance (Cochran’s test, 
P>0.05) and analysed by using 1-way AN OVA follow- 
ing the guidelines of Day and Quinn (1989). Tukey’s 
multiple comparison test was performed to determine 
pairwise relationships. Seven measures of density 
were examined: live conch, dead conch, total conch, 
alpheids, portunids, xanthids, and total predators. 
Relationships between these seven density mea- 
sures and eight environmental variables (water 
depth, distance of the station from the center of ju- 
venile queen conch aggregation, sediment grain size, 
sediment organics, Thalassia testudinum shoot den- 
sity, weight of T. testudinum detritus, and biomass 
of the macroalgae Batophora oerstedi and Laurencia 
spp.) were examined with pairwise correlation. Log- 
transformation improved the relationships, and 
Pearson correlation coefficients are reported for the 
log-transformed variables. 
The relationships between conch density (live, 
dead, and total) and each of the five predator fami- 
lies were also examined with correlation. Variables 
were not transformed in the analysis because trans- 
formation did not improve the correlations. 
Results 
Habitat characteristics 
Depth down the flow field was relatively uniform, 
ranging from 2.8 to 3.3 m at MLW, except at E where 
depth was 2 m (Table 1). Across the flow field at 
transect D, depth increased from bare sand (1.3 m) 
to high seagrass density (3.3 m), and, at transect C, 
greatest depth (3.5 m) occurred in low density 
seagrass (C2). Sediments were fine to medium sands 
(1.4-2. 6 0 ), with mean grain size decreasing slightly 
(increasing 0) with depth over both transects C and 
D (Table 1). Organic content of the sediments across 
transect D also increased with depth, ranging from 
2.7% (station Dl) to 5.2% (station D4). The range of 
organic content in the down flow-field dimension was 
3. 0-4.6%. 
Thalassia testudinum shoot density decreased down 
the flow field from 784 to 320 shoots/m 2 (Table 2). Across 
the channel, shoot density increased rapidly from 0 
to >500 shoots/m 2 in both transects, as had been in- 
Table 1 
Habitat characteristics for 11 dredge stations in the Shark Rock flow field. Depth was at mean low water and distance was 
measured from each station to the center of the juvenile queen conch nursery (see Fig. 1). Means and the range of values (paren- 
theses) are given for sediment grain size and organics ( n-2 for all stations except C3, where n= 3). Data for stations C3 and D3 are 
given twice for ease of comparison in both flow-field dimensions. 
Station 
Depth 
(m) 
Distance 
(km) 
Grain size 
(0) 
Sediments 
Organics 
(% dry wt) 
Down flow field, midchannel 
A 2.8 
3.60 
2.57 (2.56-2.58) 
4.08 (3.68-4.50) 
B 
3.0 
1.00 
1.81 (1.78-1.84) 
4.05 (3.46-4.65) 
C3 
3.1 
0.55 
1.84 (1.63-1.95) 
3.54 (3.17-3.75) 
D3 
2.8 
0.55 
2.07 (2.04-2.10) 
4.56 (4.43-4.69) 
E 
2.0 
1.10 
1.89 (1.86-1.92) 
2.95 (2.95-2.95) 
F 
3.3 
4.50 
2.04 (1.97-2.12) 
3.99 (3.98-4.00) 
Across flow field 
Transect C 
Cl 
2.0 
0.70 
1.51 (1.27-1.74) 
2.18 (2.16-2.21) 
C2 
3.5 
0.70 
1.78 (1.73-1.83) 
3.31 (3.09-3.53) 
C3 
3.1 
0.55 
1.84 (1.63-1.95) 
3.54(3.17-3.75) 
Transect D 
Dl 
1.3 
0.60 
1.44 ( 1.27-1.60) 
2.72 (2.60-2.84) 
D2 
2.1 
0.55 
1.73 (1.72-1.74) 
3.12 (3.06-3.19) 
D3 
2.8 
0.55 
2.07 (2.04-2.10) 
4.56 (4.43-4.69) 
D4 
3.3 
0.70 
1.87 (1.60-2.14) 
5.24 (5.12-5.37) 
