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Fishery Bulletin 107(1) 
September, and October combined) because the warmest 
months are when these fishes are found. 
Second, the relationship between the annual abun- 
dance of warm water fishes and water temperature 
was examined in both estuaries. Correlations were cal- 
culated between the mean annual, mean semi-annual, 
and mean summer temperatures and fish abundances 
by estuary. 
Third, the weekly occurrence of the warm-water fishes 
was compared between estuaries. Catch abundances and 
means were derived for each week. Next, for each year, 
first appearance (at least 5% of the peak abundance), 
peak appearance, and last appearance were identified 
and a mean and standard deviation were calculated 
for each estuary. Correlations then were calculated 
for these measures of timing between estuaries. The 
weeks of first, peak, and last appearance were compared 
between estuaries by using a two-sample t-test and as- 
suming equal variances (Johnson and Bhattacharyya, 
2001 ). 
Fourth, the weeks of first appearance, peak appear- 
ance, and last appearance were compared with estua- 
rine temperatures. For each estuary, mean tempera- 
tures were derived at certain times of year. The weeks 
of first appearance were regressed upon temperatures 
for June 1 of each year, peak appearance weeks were 
regressed upon peak annual temperatures, and last ap- 
pearance were regressed upon October 1 temperatures. 
June l s and October 1 were used because these are the 
dates between which the waters of Narragansett Bay 
and Long Island Sound are typically warm enough to 
sustain warm-water fishes. 
Finally, the timing of northern puffer occurrence was 
examined in detail. This species was chosen for this 
analysis because of its abundance in both areas and 
because data were consistent enough to determine the 
peak week at which the species was captured. A correla- 
tion was calculated between weeks of peak appearance 
of the northern puffer in the two locations. In addition, 
correlations were calculated between the peak week of 
fish occurrence and temperature, as well as between the 
peak week of fish occurrence and the peak week for the 
50% cumulative temperature for each year (calculated 
as the median temperature for the cumulative daily 
temperature degrees, termed “degree days”). 
Results 
Comparison of warm-water fish fauna 
The total number of warm-water fish sampled in Nar- 
ragansett Bay (1987-2001) was 4683, and the total 
warm-water fish sampled in Long Island Sound (1984- 
2000) was 7075, for a total of 11,758 individuals. The 
most frequently occurring species was Atlantic moonfish 
(66.3%), followed by crevalle jack (9.6%), and northern 
puffer (8.1%) (Table 2). 
The number of warm-water fishes has increased in 
more recent years of the survey. Most warm-water fish 
were caught in 1994, 2000, and 1998, whereas the few- 
est warm-water fish were caught in 1987, 1991, 1992, 
1993, and 1995 (Fig. 2). A rank correlation between 
catch abundance and year indicated that the abundance 
of warm-water fish has increased (r=0.73; P=0.003). 
The abundance of warm-water fish was correlated 
between Narragansett Bay and Long Island Sound. A 
correlation in abundance between areas that included 
data from all years was not signifi- 
cant (r=0.17, P- 0.56), but when 1994 
was excluded, a significant correla- 
tion was found (r=0.83, P=0.001). The 
annual abundances of the dominant 
species were also correlated between 
Narragansett Bay and Long Island 
Sound: Atlantic moonfish (omitting 
1994) ( r - 0.81, P=0.001), northern 
puffer (r = 0.63, P=0.02), and plane- 
head filefish (r=0.56, P=0.04). There 
was no significant correlation between 
the number of bigeye or crevalle jack 
caught in Narragansett Bay and Long 
Island Sound. 
The observed species richness of 
warm-water fishes in Narragansett Bay 
and Long Island Sound were 26 and 28 
species, and the resulting jackknife es- 
timates of species richness were 33.9 
and 39.2 species. Species richness did 
not differ significantly between estu- 
aries {t- 2.5, df=31, P>0.05). The spe- 
cies accumulation curves are similar 
in slope, although the curve for Long 
Island Sound is steeper and species 
2000 
1750 
1500 
1250 
1000 
O 
750 
500 
250 
□ Narragansett Bay 
■ Long Island Sound 
LL. 
Ill 
n a 
a 
■ I 
i 
1987 1988 1989 1990 199! 1992 1993 1994 1995 1996 1997 1998 1999 2000 
Year 
Figure 2 
Sum of warm-water fish caught in trawl and seine surveys in Narragansett 
Bay and in Long Island Sound for the years 1987-2000. 
