Turnure et al. : Patterns of intra-estuarine movement in adult Cynoscion regalis 
169 
River-Great Bay estuary, New Jersey). At the seasonal 
scale, active (i.e., mobile) telemetry was used to quanti- 
fy estuary-wide, meter-scale movements of individually 
tagged animals on a weekly basis across the months 
from late spring to fall. At the diel scale, patterns of 
movement and distribution were examined on an hour- 
ly basis through the use of active telemetry during the 
summer months. 
Materials and methods 
Study areas 
Seasonal movements were examined in the Mullica 
River-Great Bay estuary and adjacent Little Egg Har- 
bor estuary, and diel movements were examined in a 
small region in the lower Mullica River known as Deep 
Point (Fig. 1). The Mullica River-Great Bay system is 
a relatively small, shallow (with depths mostly <2 m), 
drowned river valley dominated by salt marsh (Ken- 
nish, 2004). With the majority of its upstream portion 
flowing through the undeveloped Pinelands National 
Reserve, this watershed is considered one of the least 
anthropogenically disturbed estuaries in the north- 
eastern United States (Good and Good, 1984; Kennish 
and O’Donnell, 2002). The adjacent Little Egg Harbor 
estuary is also relatively shallow, but it is character- 
ized as a barrier island estuary with significantly fewer 
freshwater inputs than the Mullica River-Great Bay 
system (Kennish, 2001, 2004). Both estuaries are in- 
cluded within the NOAA Jacques Cousteau National 
Estuarine Research Reserve (Kennish, 2004). 
Acoustic telemetry 
Tagging procedure and general characteristics of tagged 
fish All adult weakfish (>230 mm in total length 
[TL], which is size at maturity based on Nye et al., 
2008) examined in this study were captured by hook 
and line and subsequently tagged during 2008 (from 
11 June to 11 September) by abdominal implantation 
of individually coded acoustic transmitters (CAFT and 
MS series 2 , Lotek Wireless Inc., St. John’s, Newfound- 
land; with a 5-s signal repeat rate) by the method of 
Turnure et al. (in press). After full recovery, fish were 
released within 100 m of their original site of capture 
(Table 1). 
Seasonal patterns of movement were observed in 
2008 for acoustically tagged fish (n- 29; length range: 
273-591 mm TL, mean: 401 mm [standard error (SE) 
15) from 19 May to 4 December 2008. A subset of in- 
dividuals (n=9; length range: 337-540 mm TL, mean: 
456 mm TL [SE 22]) were monitored at the diel scale in 
the lower Mullica River at Deep Point (Fig. 1) from 30 
June to 31 July 2008. Active tracking, as part of a con- 
2 Mention of trade names or commercial companies is for iden- 
tification purposes only and does not imply endorsement by 
the National Marine Fisheries Service, NOAA 
current study (Turnure et al., in press), began in May 
2008 to detect weakfish (tagged in 2007) that were po- 
tentially immigrating to the estuary. However, no such 
immigrants were detected in 2008. All fish monitored 
in the study presented herein were tagged beginning 
in June 2008. The area used in the study of diel move- 
ments was chosen because multiple fish were tagged 
and released there, making it possible to examine their 
day-night movements as an aggregation. All fish used 
in these analyses were considered successfully tagged 
on the basis of subsequent redetections or movement 
from the study area (Turnure et al., in press). The bat- 
tery duration of the deployed acoustic transmitters 
ranged from 229 to 719 days for both the seasonal and 
diel components of this study, allowing for monitoring 
of fish until final emigration from the study area in the 
fall (for further description of weakfish emigration, see 
Turnure et al., in press). 
Active telemetry Active telemetry was used at both the 
seasonal and diel scales to examine patterns of move- 
ment in 2008. For active tracking from a small boat, 
a directional hydrophone (LHP_1, Lotek Wireless Inc., 
Newmarket, Ontario, Canada) was attached to a signal 
processor (SRX-400, Lotek Wireless Inc.). At each pre- 
determined sampling location (Fig. 1), the hydrophone 
was lowered approximately 3 m underwater and turned 
in 90° increments for a full rotation. When transmit- 
ters were audibly detected, the boat was positioned to 
maintain close proximity (signal power >115 dB and 
gain < 15) and fish location was recorded, with a GPS 
unit, together with the tag identification number, sig- 
nal power (in decibels), and gain. Although variable be- 
cause of ambient weather conditions, the active listen- 
ing range of the hydrophone averaged approximately 
500 m. For further discussion of the general active 
tracking procedure in this estuary, see Ng et al. (2007), 
Sackett et al. (2007), and Turnure et al. (in press). 
Every week from 19 May to 4 December 2008 (ex- 
cept for the week of 17 November because of inclem- 
ent weather), 120 predetermined locations (Fig. 1) that 
covered a majority of the navigable Mullica River- 
Great Bay system were sampled during daylight hours 
(0700-1900) as described previously. For most of the 
tracking events, both the bay and river locations were 
sampled on different days within the same week (for a 
detailed description of tracking protocol, see Turnure 
et al., in press). 
Active tracking also occurred from 30 June to 31 
July 2008 (9 tracking events), to identify diel patterns 
of movement in weakfish near Deep Point in the Mul- 
lica River. During each tracking event, the sampling 
locations in a subset of 9 predetermined points were 
visited on a rotating basis (Fig. 1). After detection and 
subsequent meter-scale localization of individuals at a 
tracking point, the subsequent locations were visited 
until work at all 9 points was completed. Then, the 
rotation was repeated, beginning at point 1 until the 
daily tracking event was over. The average tracking 
event lasted 5 h and 43 min. To determine the effect 
