330 
Fishery Bulletin 113(3) 
29°48'0"N 
93°56'0"W 
Point 
Louisiana 
O Sample stations 
Land 
Reef areas 
93°20'0"W 
Dredge Spoil g 
Island 
Figyre 2 
Maps of the locations of the 3 stations (o) at each of 4 sites in coastal Louisiana where resident reef 
communities and reef structure were sampled in 2010: (A) Sabine Lake, (B) Sister Lake, (C) northern 
Calcasieu Lake, and (D) southern Calcasieu Lake. All reef areas were determined from sonar data, ex- 
cept the reef area in northern Calcasieu Lake, which is based on only GPS coordinates for the footprint 
of a cultch planting in 1969. The sites at Sabine and Sister lakes were sampled in summer 2010 with 3 
samples per station; the northern and southern sites at Calcasieu Lake were sampled in fall 2010 with 
4 samples per station. 
interstitial reef space, respectively. Total numbers of 
oysters, of market-size oysters (shell height: >75 mm), 
and of seed oysters (shell height: 25-75 mm) were 
counted. At tray retrieval, the number of hooked mus- 
sels ( Ischadium recurvum) within 1.0 L of substrate 
per tray was counted as an indicator of settlement of 
other (nonoyster) sessile organisms. 
Reef integrity and vertical relief were estimated at 
each sample station. To estimate reef integrity (per- 
centage of area that consisted of solid reef), 20 hap- 
hazard measurements were taken by quickly tapping 
the bottom of the seafloor twice with a long pole and 
recording the bottom type (solid, mixed shell and mud, 
or mud). Solid reef was assigned a value of 1.0, mixed 
shell and mud was assigned a value of 0.5, and mud 
was assigned a value of 0.0. An index of integrity was 
calculated by adding the assigned values and dividing 
by 20. To measure vertical relief, 20 haphazard depth 
measurements were taken at each station. The differ- 
ence between the 2 extreme depth measures was used 
as an index of vertical relief. 
Water quality Upon retrieval of each nekton sampling 
tray, dissolved oxygen (DO; measured as milligrams per 
liter), salinity, and temperature (measured in degrees 
Celsius) data were collected at each sample station at 
the surface (~10 cm below the surface) and the bottom 
( ~ 10 cm above the bottom) of the water column with a 
YSI Model 85 4 multiparameter sensor (YSI, Inc., Yellow 
Springs, OH). One surface water sample was collected 
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