426 



Abstract — We determined the dis- 

 tribution of multiple (?i=68; 508-978 

 mm total length [TLJ) striped bass 

 (Morone saxatilis) along the estua- 

 rine salinity gradient in the Mullica 

 River-Great Bay in southern New 

 Jersey over two years to determine 

 the diversity of habitat use and the 

 movements of striped bass. Ultrasoni- 

 cally tagged fish were detected in this 

 estuarine area by means of wireless 

 hydrophones deployed at four gates 

 inside the entrance of the study area 

 and farther up to tidal freshwater (38 

 km). Numerous individuals frequently 

 departed and returned to the estuary, 

 primarily in the spring and late fall 

 over periods of 15-731 days at liberty. 

 The period of residency and degree of 

 movement of individuals to and from 

 the estuary varied extensively among 

 seasons and years. The diversity of 

 movements in and out of, as well as 

 within, the estuary differed from the 

 less-complex patterns reported in ear- 

 lier studies, perhaps because of the 

 comprehensive and synoptic nature 

 of this study. 



Diversity of estuarine movements of striped bass 

 {Morone saxatilis): a synoptic examination of 

 an estuarine system in southern New Jersey 



Kenneth W. Able (contact author) 

 Thomas M. Grothues 



Email address for K. W, Able: ablemimannerutgers.edu 



Marine Field Station, Institute of Marine and Coastal Sciences 



Rutgers University 



800 c/o 132 Great Bay Boulevard 



Tuckerton, New Jersey 08087-2004 



Manuscript submitted 10 April 2006 

 to the Scientific Editor's Office. 



Manuscript approved for publication 

 30 March 2007 by the Scientific Editor. 



Fish. Bull. 105:426-435(2007). 



Striped bass (Morone saxatilis) are an 

 economically and ecologically impor- 

 tant species along most coasts of the 

 United States, and especially along 

 the east coast and into Canada (Klein- 

 MacPhee, 2002). The degree to which 

 this species uses estuaries along the 

 east coast appears to vary among and 

 within estuaries. From North Carolina 

 southward most striped bass remain 

 in rivers and estuaries (Haeseker et 

 al., 1996; Bjorgo et al., 2000), as does 

 the northernmost population in the 

 Gulf of St. Lawrence (Coutant, 1985). 

 North of North Carolina to the Bay 

 of Fundy, striped bass can be highly 

 migratory (Waldman et al., 1990; 

 Rulifson and Dadswell, 1995). Much 

 of the research effort in this region 

 has focused on the coastal migra- 

 tions and there has been less effort 

 on within-estuary movements. Both 

 coastal and within-estuary move- 

 ments have become more important 

 to understand because 1) the recovery 

 of the species (Wooley et al., 1990; 

 Richards and Rago, 1999), especially 

 at the current higher densities, may 

 influence its movement patterns, and 

 2) there is the possibility that there 

 are distinct contingents, including 

 estuarine residents, that are critical 

 to understanding stock structure for 

 fishes in general (Begg and Waldman, 

 1999), but especially for striped bass 

 (Secor et al., 2001). 



In the past, most attempts to exam- 

 ine estuarine movements have been 

 based on fish caught in local fisher- 

 ies (Rulifson and Dadswell, 1995) 

 and tagged-recaptured fish (Bore- 

 man and Lewis, 1987; Waldman et 



al., 1990). However, in recent years 

 the development of otolith micro- 

 chemistry has helped scientists to 

 recognize the importance of distinct 

 substocks or contingents and their 

 migrations (Secor, 1999) that have 

 the potential to be indicative of hom- 

 ing (Thorrold et al., 2001; Gilland- 

 ers, 2005). These concepts have been 

 applied to striped bass as well, and 

 resident, mesohaline, and coastal mi- 

 gratory contingents have been recog- 

 nized within the same estuarine and 

 river system (Secor, 1999; Zlokovitz 

 et al., 2003), as well as the annual 

 variation in the migratory patterns 

 of these contingents (Morris et al., 

 2003). Additionally, the development 

 of biotelemetry in general (Cooke et 

 al., 2004; Heupel et al., 2006) and 

 smaller ultrasonic tags and passive 

 receivers has increased the possibil- 

 ity for more accurate and frequent 

 detection of fish and has enhanced 

 our ability to study fish movements 

 (Arnold and Dewar, 2001; Sibert and 

 Nielsen, 2001). These efforts conduct- 

 ed on striped bass previously focused 

 on introduced populations in freshwa- 

 ter reservoirs (e.g., Jackson and High- 

 tower, 2001; Young and Isley, 2002), 

 with exceptions in North Carolina 

 (Haeseker et al., 1996; Carraichael 

 et al 1998), Maryland (Hocutt et al., 

 1990), and New Jersey (Tupper and 

 Able, 2000). More detailed studies are 

 necessary to determine how estuarine 

 and ocean use varies among individu- 

 als over seasons and years. This is 

 especially necessary because much of 

 the past focus has been on large es- 

 tuarine and river systems such as the 



