Shepherd et al Migration routes of Pomatomus saltatiix along the Atlantic coast 



569 



44N 



42-N 



40°N 



38°N 



36' N 



44'>N 



42°N 



40°N- 



SS^N 



36"N 



•A' 





NH 



NY 



"^ 



t 



s MA BTo • \'^" '" 



'I U m 



September 



Kilot-'rams 

 o l-_S(lll 

 O .'i()l-:(lll(l 

 O 2(H)l-i:(«lll 

 O 12001-2 7^1111 



914 m 



NC 







October 



Kildgranis 

 o 1-500 

 O 501-2000 

 O 2001-12000 

 O 1 200 1 -27300 



.^, 



\ f \ ^Z^- 



NH y-' 



I, iCT R 



November 



Kilogriini^ 

 500 

 O 501-2000 

 O 2001-12000 

 O 12001-27300 





VA 



NC 



December 



Kiloiirams 

 o 1-500 

 O 501-2000 

 O 2001-12000 

 O 12001-27300 



78=\V 



(i6"W 78"W 



74' W 



Figure 7 



Distribution of bluefish ^Pamatomua saltatnx) in the Middle Atlantic Bight based 

 on commercial logbook catch records (2001-2003) for all gear types. 



greater than 50 km per day would imply that some type 

 of passive transport supplemented active swimming 

 movement. The offshore distribution of bluefish in the 

 South Atlantic Bight during winter, as inferred from 

 tags, may provide an opportunity for bluefish to use the 

 Gulf Stream during the northern migration. 



Several recent studies have evaluated the stock struc- 

 ture of bluefish along the Atlantic coast by using genetic 

 material (Chiarella and Conover, 1990; Graves et al., 

 1993; Davidson, 2002) and morphometric characteris- 

 tics (Austin et al., 1999). These studies have concluded 

 that bluefish along the U.S. Atlantic coast comprise a 

 single stock. The tag recovery information for bluefish 

 illustrates differences in movement patterns among 

 areas, but these groupings do not imply unique stock 

 characteristics. Consequently, there is no evidence from 

 the tag recovery information that refutes the single 

 stock hypothesis. 



Implementation of a well-designed tag and release 

 program is critical for analytical evaluation of migra- 

 tion (Schwarz et al., 1993). Limitations associated with 

 tag recovery must be accounted for in the design of an 



effective tagging program. Recovery of most tags is 

 a function of fishing effort; therefore recaptured tags 

 must be considered in the context of the fisheries that 

 will provide the recoveries. Unknown variations in fish- 

 eries over the past four decades may have influenced 

 the patterns of bluefish tag recoveries in the NMFS 

 and ALS programs, ultimately influencing interpreta- 

 tion of the results. In addition, time-at-large for fish 

 in both programs was generally less than one year 

 which may be due to tag-induced mortality and tag 

 loss (Henderson-Arzapalo et al., 1999). Bluefish tagged 

 in Western Australia were generally at large for less 

 than a year and experienced tag losses between 25% 

 and 38% (Young et al., 1999). The NMFS and ALS 

 programs demonstrate that tagging is a viable tool 

 in analyses of bluefish populations, but it has limita- 

 tions. Using the knowledge gained from these tagging 

 programs, scientist may find that a renewed tagging 

 effort incorporating recent technological advances will 

 provide further insight into the migratory behavior 

 of bluefish and, in particular, the behavior linked to 

 environmental cues. 



