168 
Fishery Bulletin 113(2) 
Mullica River 
* . / • 
Lower Mullica River 
Die I active tracking points 
"Big Creek * 
• LSHC*V. 
* . 
Marshelder t Channel 
7 - .;•* 
• • • •:.< . 
* * Great • 
Bay 
• , L/tt/e Egg 
• /n/et 
• # , Atlantic 
^ Ocean 
39°30'0"N ■ 
'Main Marsh • GrassyVhannel 
Thorofere # • 
• Sampling points 
O Average minimum 
detection range (500 m) 
Figure 1 
Study areas within the Mullica River-Great Bay estuary in southern New Jersey for the seasonal and diel scales in 
the study of weakfish ( Cynoscion regalis ) movement conducted in 2008. The locations of the sampling points (120) 
were monitored with active telemetry used to evaluate seasonal movements in 2008, including the area (shown in 
the inset square box) at Deep Point in the lower Mullica River surveyed for an the evaluation of diel movements. 
LSHC=Little Sheepshead Creek. 
1984). Although weakfish occur in estuaries and inner- 
continental-shelf habitats, the relative importance of 
estuarine systems within these regions is mostly un- 
known (Able, 2005; Woodland et al., 2012). We do know 
that they establish seasonal residency in estuaries in 
the Middle Atlantic Bight (Turnure et al., in press; 
Manderson et al., 2014), where they both feed (Harf- 
mart and Brandt, 1995) and reproduce (May-July; 
Connaughton and Taylor, 1994, 1995; Luczcovich et al., 
1999; Able and Fahay, 2010). Previous egg and plank- 
ton sampling (Ferraro, 1980), reproductive histology 
(Lowerre-Barbieri et al., 1996; Nye et al., 2008), and 
gonadosomatic indices (Taylor and Villoso, 1994) have 
delineated weakfish as iteroparous nocturnal spawners, 
generally commencing reproductive behavior around 
the evening crepuscular period. In both field and labo- 
ratory passive acoustic studies, the drumming of the 
swim bladder of weakfish before spawning has been 
used to better define their location (Luczkovich et al., 
1999) and the diel periodicity (Connaughton and Tay- 
lor, 1995) of their reproduction. 
Because aspects of weakfish life history (e.g., re- 
production and migration) occur at multiple tempo- 
ral scales (i.e., seasonally and daily), it is prudent to 
evaluate weakfish estuarine movements within these 
time frames. Earlier investigations of weakfish move- 
ments within estuaries had been either too geographi- 
cally coarse to resolve fine-scale patterns at biologically 
relevant timescales for individuals (Nesbit, 1954; Thor- 
rold et al., 2001) or were limited to juveniles (Tyler 
and Targett, 2007). Previous research also has quan- 
tified homing to natal estuarine systems, suggesting 
that weakfish exhibit a high degree of spawning-site 
fidelity over broad regional areas (i.e., Chesapeake 
Bay and Delaware Bay; Thorrold et al., 2001), but the 
degree to which weakfish use small, shallow estuaries 
is relatively unknown, with the exception of a recent 
study (Manderson et al., 2014). A better understanding 
of weakfish movements and how extensively and in- 
tensively individuals use these estuarine habitats will 
clarify aspects of their complex life history and popula- 
tion dynamics (i.e., connectivity between estuaries and 
coastal habitats) and begin to delineate critical habi- 
tats for this species. 
Our objectives were to characterize and quantify 
the fine-scale patterns of movement of individual adult 
weakfish at seasonal and diel temporal scales within 
a relatively undisturbed estuarine system (Mullica 
