Graves et al.: Use of archival tags to study postrelease survival of and habitat use by estuarine and coastal fishes 
381 
Figure 6 
Cumulative percentage of archived data that are successfully 
received by the user as a function of the number of days of 
transmitted data during the 30-d transmission period for the 
X-tag high-rate archival tags (Microwave Telemetry, Inc.) pro- 
grammed with Satellite-In-View (SIV™) technology at Mid- 
Atlantic latitudes (available from R. P. Howey, 2009, University 
of Bath, Bath BA2 7AV, UK). Because of the frequency of Argos 
satellite passes, tags transmitting at higher latitudes will 
approach asymptotic data recovery more rapidly, and those 
transmitting at lower latitudes will approach asymptotic data 
recovery more slowly. 
clear pelagic seas, RMS errors associated with 
geolocation estimates based on light and sea 
surface temperature data exceed 100 km (Teo 
et al., 2004; Nielsen and Sibert, 2007), and the 
hyperdynamic light conditions characteristic 
of turbid, tidal coastal waters such as those of 
Chesapeake Bay, which impede the accurate 
characterization of sunrise and sunset, would 
result in even greater RMS errors. Consequent- 
ly, light-based geolocation would seem to have 
limited applicability to short-term PSAT studies 
of estuarine and coastal fishes. 
Habitat-use studies based on PSAT data may 
benefit from analytical frameworks that incor- 
porate repeated measures to account for the in- 
herent within-individual autocorrelation (James 
et al., 2006; McMahon et al., 2007). Diel differ- 
ences were not evident in depth or temperature 
use by coastal migrant striped bass during the 
January-March tag deployment period. Simi- 
larly, there were no significant differences in 
depth and temperature use among individuals 
or deployment days. During winter, the adult 
striped bass staging in coastal Virginia and 
North Carolina waters forage heavily on dense 
schools of Atlantic menhaden ( Brevoortia tyran- 
nus) before traveling into tributaries to spawn 
(Raney, 1952). The coastal waters of Virginia 
and North Carolina are fairly shallow and well- 
mixed, thus the movements of schooling striped 
bass during our tag deployment duration likely 
reflect pursuit of prey by a school of predators 
rather than the selection of preferred depth or 
temperature ranges by individual striped bass. 
Behavioral rhythms in time-series resulting from ul- 
trasonic telemetry and, more recently, recovered PSATs, 
are ideally analyzed by fast Fourier methods if all da- 
ta are recovered (Hartill et al., 2003; Shepard, et al., 
2006). Fast Fourier analysis of full depth time-series 
data streams from three recovered PSATs deployed on 
striped bass indicate subtle daily, 12-hour, and 8-hour 
periodicities. Daily periodicities may represent onshore- 
offshore movements of striped bass schools into shal- 
lower and deeper waters when they chase menhaden 
prey, 12-hour periodicities may correspond to ambient 
diel light regimes, and 8-hour periodicities may indicate 
subtle tidal or current effects in the use of depth by 
striped bass. Mid-Atlantic coastal waters and estuar- 
ies such as Chesapeake Bay feature semidiurnal tides; 
tidal stage had substantial impact on movements and 
habitat use of striped bass in Delaware Bay (Tupper 
and Able, 2000). Alternately, the 8-and 12-hour period- 
icities observed in the striped bass data may result from 
a combination of harmonics resulting from behaviors 
not strictly sinusoidal in character (Chatfield, 1996). 
Fourier methods should be applied only to full (100%) 
data streams to avoid inferring direct spectral relation- 
ships between two adjacent data packets that are in 
reality separated in time by sections of untransmitted 
archived data. 
We investigated the applicability of a new generation 
of smaller PSATs for studies of estuarine and coastal 
fishes and have provided insights into postrelease sur- 
vival and habitat use of prespawn aggregating adult 
striped bass in the winter recreational fishery along 
the coast of Virginia. Results of this study indicate 
that tag fouling with physical structures, tag damage 
resulting from interaction with conspecifics, preda- 
tors, or scavengers, and reduced transmission efficiency 
due to beaching or entanglement are not major liabili- 
ties for striped bass. In fact, the potential for reduced 
transmission efficiency is more than offset by increased 
probability of tag recovery resulting in complete data 
retrieval and the opportunity to reuse the tag at a 
greatly reduced cost. Collectively, the results of this 
study on striped bass indicate that the new generation 
of smaller PSATs may prove to be an effective tool for 
studying the postrelease survival of and habitat use by 
other estuarine and coastal fishes. 
Acknowledgments 
The authors would like to thank K. Neill and the crew 
of the Healthy Grin for all of their efforts to deploy the 
tags. We thank P. Howey and R. Tolentino (Microwave 
Telemetry, Inc.) for technical assistance with tags and 
R. Howey (University of Bath) for developing the soft- 
