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Fishery Bulletin 96(2), 1998 
Sound, from 15 to 30°C in Tampa Bay, and from 18 
to 32°C in Charlotte Harbor. 
Pinfish were sampled monthly from 1989 to 1994 
at fixed seine and trawl stations. Fixed stations were 
approximately evenly distributed throughout shal- 
low- and deepwater areas and included sites in ma- 
jor rivers in Tampa Bay and Charlotte Harbor. 
Monthly sampling began in 1992 in Choctawhatchee 
Bay, in 1989 in Tampa Bay, and in 1991 in Charlotte 
Harbor. Samples were collected with a 21.3-m x 1.8- 
m, 3.2-mm stretched-mesh seine, or a 6.1-m, 38-mm 
stretched-mesh otter trawl containing a 3.2-mm 
stretched-mesh codend liner. At beach stations, seines 
were set adjacent to the shoreline and hauled on- 
shore; at offshore stations (<1.4 m), seines were set 
in open-water habitats away from the shoreline and 
retrieved offshore. In rivers, seines were set from the 
shoreline in a semicircular pattern from a boat. In 
deep water (>1.6 m), trawls were towed 1 knot for 
5 min at river sites and for 10 min at bay sites. Three 
hauls or tows were made at each fixed station dur- 
ing daylight hours. Sampling occurred during the 
first two weeks of each month. 
Pinfish were also sampled in spring (March to 
June) at randomly selected sites to provide more ac- 
curate estimates of YOY abundance. To coordinate 
sampling logistics, each bay was subdivided into 5-6 
arbitrarily lettered, permanent zones (bay: zones A- 
E; rivers: zone F). All bay zones encompassed about 
equal area. Within each zone, 1' latitude x 1' longi- 
tude microgrids, representing the sites to be sampled, 
were randomly selected within randomly selected 1° 
latitude x 1° longitude grids. Sampling entailed ran- 
domly selecting a zone and then sequentially sam- 
pling all sites within each zone. At each site, three 
hauls were made with the same gears 
and deployment techniques used at fixed stations. 
Random sampling began in Choctawhatchee Bay in 
1993 and in Tampa Bay and Charlotte Harbor in 1989 
and occurred over eight, twelve, and ten weeks, re- 
spectively. 
For all hauls, total numbers of pinfishes were 
counted, standard lengths were measured (±1 mm) 
for 20 randomly selected individuals per sample, and 
all fish were released. When large numbers of indi- 
viduals (>1,000) were captured, the total number was 
estimated by fractional expansion of subsampled 
portions of the total catch split with a modified 
Motoda splitter (Motoda, 1959). Salinity (ppt), tem- 
perature (°C), depth (m), and bottom types were also 
recorded at all sites. Dominant vegetation types were 
recorded at seine sites only. 
Seasonal changes in YOY 
abundance and size structure 
To examine seasonal changes in YOY abundance in 
shallow- and deepwater areas, comparable monthly 
mean number of individuals per 100 m 2 were calcu- 
lated from fixed station data by year. I separated YOY 
data used in all analyses from data on older 
individuals by using maximum size limits se- 
lected from monthly length-frequency plots. 
Monthly length frequencies based on propor- 
tions of fish found in each length class were 
combined over years to describe within-year 
trends rather than year-to-year variability. 
Length maximum size limits used for 
Choctawhatchee Bay data were in agreement 
with the maximum lengths of scale-aged YOY 
pinfish from Pensacola Bay (Hansen, 1970). 
Depth distribution 
To determine whether YOY were restricted 
to depth ranges during the period surround- 
ing peak abundance, the cumulative fre- 
quency distributions of trawl and YOY pin- 
fish depth occurrences were compared by 
using the Kolmogorov-Smirnov test (Perry 
and Smith, 1994). The cumulative frequency 
distributions for YOY pinfish were con- 
structed by weighting depth at each random 
site by the number of YOY pinfish captured 
at that site. Only spring data from the first 
Figure 1 
Map of Florida showing the locations of Choctawhatchee Bay, Tampa 
Bay, and Charlotte Harbor. 
