89 
A comparison between warm-water 
fish assemblages of Narragansett Bay 
and those of Long Island Sound wafers 
Email address for contact author: amclean@gso.un.edu 
1 University of Rhode Island 
Department of Fisheries, East Farm Campus 
Kingstown Road 
Kingston, Rhode Island 02881. 
Present address: Rocky Hill School 
530 Ives Road 
East Greenwich, Rhode Island 02818. 
2 University of Rhode Island, Graduate School of Oceanography 
South Ferry Road 
Narragansett, Rhode Island 02882. 
3 National Marine Fisheries Service, NOAA 
Northeast Fisheries Science Center 
28 Tarzwell Drive 
Narragansett, Rhode Island 02882. 
Abstract — Fish species of warm- 
water origin appear in northeast- 
ern U.S. coastal waters in the late 
summer and remain until late fall 
when the temperate waters cool. 
The annual abundance and species 
composition of warm-water species is 
highly variable from year to year, and 
these variables may have effects on 
the trophic dynamics of this region. To 
understand this variability, records 
of warm-water fish occurrence were 
examined in two neighboring temper- 
ate areas, Narragansett Bay and Long 
Island Sound. The most abundant fish 
species were the same in both areas, 
and regional abundances peaked in 
both areas in the middle of Septem- 
ber, four weeks after the maximum 
temperature in the middle of August. 
On average, abundance of warm-water 
species increased throughout the years 
sampled, although this increase can 
not be said to be exclusively related to 
temperature. Weekly mean tempera- 
tures between the two locations were 
highly correlated (r = 0.99; TNO.OOl). 
The warm-water fish faunas were dis- 
tinctly different in annual abundances 
in the two areas for each species by 
year (1987-2000), and these differ- 
ences reflect the variability in the 
transport processes to temperate estu- 
aries. The results reveal information 
on the abundance of warm-water fish 
in relation to trends toward warmer 
waters in these regions. 
Manuscript submitted 27 January 2008. 
Manuscript accepted 24 September 2008. 
Fish. Bull. 107:89-100 (2009). 
The views and opinions expressed 
or implied in this article are those 
of the author and do not necessarily reflect 
the position of the National 
Marine Fisheries Service, NOAA. 
Abby Jane M. Wood (contact author)' 
Jeremy S. Collie 2 
Jonathan A. Hare 3 
Temperate estuaries are subject to 
broad temperature variations related 
to seasonal warming and cooling. 
Resident fish species are able to sur- 
vive these ranges in temperature, 
but these variations in temperature 
also create the conditions for seasonal 
habitat for boreal and subtropical fish 
species. These cold and warm-water 
species contribute significantly to the 
overall species diversity of temperate 
estuaries worldwide (Lenanton and 
Potter, 1987; Hutchins, 1991) and play 
a significant role in the trophic inter- 
actions in the ecosystem even though 
they are not present year round (Able 
and Fahay, 1998). 
Temperature and faunal variations 
are well documented in temperate 
estuaries bordering the northeast- 
ern U.S. continental shelf ecosystem 
(Rountree and Able, 1992; Tremain 
and Adams, 1995), which extends 
from Cape Hatteras, North Carolina, 
to Nova Scotia, Canada (Fig. 1). Cape 
Hatteras is generally the northern 
barrier for warm-temperate fauna, 
but highly mobile species are able to 
move northward during warm sea- 
sons (Bigelow and Schroeder, 1953; 
Briggs, 1974). There are many estu- 
aries stretching from Cape Hatteras 
to Nova Scotia, and estuarine fish as- 
semblages have been well described 
in more southern estuaries, such as 
Chesapeake Bay (Murdy et al., 1997), 
Little Egg Inlet, New Jersey (Able 
and Fahay, 1998), and Sandy Hook, 
New Jersey (Grant, 1991). However, 
there is little information available 
regarding the abundance of warm-wa- 
ter fishes in estuaries farther north in 
the estuarine waters of Narragansett 
Bay (Narragansett Bay and several 
large salt ponds along the Atlantic 
coast of Rhode Island are hereafter 
referred to simply as Narragansett 
Bay) and Long Island Sound. 
The goal of this study was to de- 
scribe the warm-water fish fauna in 
the areas of the northeast U.S. con- 
tinental shelf ecosystem represented 
by Narragansett Bay and Long Is- 
land Sound. We compiled a list of 
the warm-water fish species found in 
Narragansett Bay and Long Island 
Sound, calculated species richness, 
and compared species abundances be- 
tween the two estuaries. Collected da- 
ta were then used to address whether 
there had there been an increase in 
the occurrence of warm-water fishes 
