189 
Migratory and within-estuary behaviors of 
adult Summer Flounder {.Paralichthys den tat us) 
in a lagoon system of the southern mid-Atlantic 
Bight 
Email address for contact author: kcapossela@dnr.state.md.us 
Virginia Institute of Marine Science 
Department of Fisheries Science 
College of William 8. Mary 
1208 Greate Road, PO Box 1346 
Gloucester Point, Virginia 23062 
Present address for contact author: Maryland Department of Natural Resources 
301 Marine Academy Drive 
Stevensville, Maryland 21666 
James J Howard Marine Sciences Laboratory 
Northeast Fisheries Science Center, 
National Marine Fisheries Service, NOAA 
74 Magruder Road, Sandy Hook 
Highlands, New Jersey 07732 
Abstract— We monitored the move- 
ments of 45 adult Summer Floun- 
der ( Paralichthys dentatus) between 
June 2007 and July 2008 through 
the use of passive acoustic telemetry 
to elucidate migratory and within- 
estuary behaviors in a lagoon system 
of the southern mid-Atlantic Bight. 
Between 8 June and 10 October 
2007, fish resided primarily in the 
deeper (>3 m) regions of the system 
and exhibited low levels of large- 
scale (100s of meters) activity. Mean 
residence time within this estuarine 
lagoon system was conservatively 
estimated to be 130 days (range: 18- 
223 days), which is 1.5 times longer 
than the residence time previously 
reported for Summer Flounder in a 
similar estuarine habitat -250 km 
to the north. The majority of fish 
remained within the lagoon system 
until mid-October, although some 
fish dispersed earlier and some of 
them appeared to disperse tempo- 
rarily (i.e., exited the system for 
at least 14 consecutive days before 
returning). Larger fish were more 
likely to disperse before mid-Octo- 
ber than smaller fish and may have 
moved to other estuaries or the in- 
ner continental shelf. Fish that dis- 
persed after mid-October were more 
iikely to return to the lagoon system 
the following spring than were fish 
that dispersed before mid-October. 
In 2008, fish returned to the system 
between 7 February and 7 April. 
Dispersals and returns most closely 
followed seasonal changes in mean 
water temperature, but photoperiod 
and other factors also may have 
played a role in large-scale move- 
ments of Summer Flounder. 
Manuscript submitted 24 May 2012. 
Manuscript accepted 5 March 2013. 
Fish. Bull. 111:189-201 (2013). 
doi 10.7755/FB.111.2.6 
The views and opinions expressed 
or implied in this article are those of the 
author (or authors) and do not necessar- 
ily reflect the position of the National 
Marine Fisheries Service, NOAA. 
Karen M. Capossela (contact author)' 
Mary C. Fabrizio' 
Richard W. Brill 2 
The continued degradation of estua- 
rine environments associated with 
eutrophication, shoreline develop- 
ment, and global climate change ne- 
cessitates a better understanding of 
how seasonal residents, like Summer 
Flounder ( Paralichthys dentatus ), 
use mid-Atlantic estuaries (Gibson, 
1994; Beck et al., 2001). Estuaries 
provide juvenile and adult Summer 
Flounder with the water tempera- 
tures, food resources, and protection 
from predation that are necessary for 
their growth and survival (Stierhoff 
et al., 2006). Summer Flounder mi- 
grate offshore in the fall and winter 
to spawn over the outer continental 
shelf before they migrate back in- 
shore the following spring, often re- 
turning to the same estuary in sub- 
sequent years (Sackett et al., 2007). 
As a result, stock abundance is influ- 
enced by local estuarine conditions 
(Ray, 2005). The use of estuaries as 
nursery habitat by Summer Flounder 
and the responses of juvenile Sum- 
mer Flounder to estuarine conditions 
have been extensively examined (e.g., 
Malloy and Targett, 1994; Tyler, 2004; 
Necaise et al., 2005; Stierhoff et al., 
2006, 2009). Only recently, however, 
have migratory and within-estuary 
behaviors of adult Summer Flounder 
been examined (Sackett et al., 2007, 
2008; Henderson, 2012). 
Migration timing traditionally has 
been determined through assessment 
of the abundance of fishes in an es- 
tuary over time with standard fish- 
eries methods, such as bottom trawl 
surveys. However, population-level 
monitoring is insufficient to under- 
stand the dynamics of emigration or 
the variation in individual responses 
(DeCelles and Cadrin, 2010). In re- 
cent years, acoustic telemetry has 
been established as a powerful tool 
for observation of individual variabil- 
ity in behaviors (Heupel et al., 2006; 
DeCelles and Cadrin, 2010). A study 
of acoustically monitored adult Sum- 
mer Flounder in the Mullica River- 
Great Bay estuary in New Jersey 
(located in the northern mid-Atlantic 
Bight [MAB]) indicated that a large 
number of fish departed the estuary 
in July, but the precise timing varied 
between years (Sackett et al., 2007). 
