Able et aL: Use of ocean and estuarine habitats by young-of-the-year Pomatomus saltatrix 



203 



On ocean beaches along northern New Jersey, sampling 

 was conducted biweekly by the U.S. Army Corps of Engi- 

 neers at 28 stations with a 15.2 x 1.8 m beach seine with 

 a 1.8-m''^ bag (6-mm mesh) during one-week periods from 

 August through October 1995-98 (Fig. 1, Table 1). At each 

 location three seine hauls were completed during daylight, 

 two near the groins bordering each site and one between 

 the groins. Comparisons between ocean and estuarine 

 beaches (Fig. 1) were conducted during 1998 with seasonal 

 sampling in the Great Bay-Little Egg Harbor estuary and 

 adjacent ocean by the Rutgers University Marine Field 

 Station. All of these samples were collected with a 30 x 

 1.8 m bag seine with 6-mm mesh in the wings and 2-mm 

 mesh in the bag. 



For all of these sampling programs bluefish were enu- 

 merated and measured to either total length, standard 

 length, or fork length, but for purposes of consistency, 

 all lengths were converted to fork length (FL) for ease of 

 comparison with earlier studies by using the regressions 

 in Able and Fahay ( 1998). 



Tag and recapture 



The spatial and temporal components of this study were 

 part of a larger sampling program to compare habitat use 

 of YOY fishes on ocean and estuarine beaches. During this 

 program, YOY bluefish were sampled during daylight hours 

 with beach seines ( 30 mx 1.8 m, 2-mm mesh bag, 6-mm mesh 

 wings) from 18 May to 28 October 1999 and from 22 May to 

 9 October 2000. The beach seines were deployed in depths 

 <1.5 m, 10-40 m from shore depending on beach slope, tidal 

 stage, wave and current conditions, and spread parallel to 

 the beach, and then pulled back to shore. Seining on ocean 

 beaches — Tuckers Island and Seven Islands (Fig. 1) — 

 typically occurred between the two hours before and after 

 low tide, whereas seining at Graveling Point occurred at 

 various times in the tidal cycle, but mostly during the 4- 

 hour window around high tide. At ocean sites, sampling at 

 all but two sites (Barnegat Light and Holgate) occurred up 

 to about 50 m from each side of groins that were present at 

 most sites. At Graveling Point, hauls were made down the 

 length of the beach. Regular, biweekly sampling across all 

 11 sites consisted of three standardized tows at each site. 



Additional sampling at these same sites used the same 

 techniques but consisted of 1-20 seine hauls per site to col- 

 lect YOY bluefish for tagging and recapture. Data from the 

 regular sampling are presented as catch per unit of effort 

 (CPUE) and data from both sampling programs were used 

 for construction of length-frequency distributions that are 

 available elsewhere (Rowe et al.''). 



Young-of-year fish were tagged as they became avail- 

 able. Individuals caught in the seines were transported 

 in buckets of water to shallow, 112-cm diameter circular 

 tanks filled to a depth of 10-15 cm with aerated seawater 

 and held at ambient conditions, typically below 25°C with 

 bottles of ice used to maintain water temperature. Then 

 they were anesthetized in a 65 mg/L solution of MS-222 

 (3-aminobenzoic acid ethyl ester methanesulfonate salt, 

 Sigma Inc., St. Louis, MO), measured to the nearest mil- 

 limeter and a sequential coded wire tag (1x0.25 mm) was 

 injected dorsolaterally behind the head and anterior to the 

 dorsal fin by using a hand-held multishot injector (North- 

 west Marine Technology, Shaw Island, WA). Each fish 

 was checked for the presence of the tag with a hand-held 

 "wand" tag detector before being released. Tagged fish were 

 allowed to recover for 1-4 hours in holding tanks and were 

 then released within the area of capture. 



This approach yielded a high rate of tag retention and 

 low mortality. In 1998, we tagged 25 fish (115-170 mm FL) 

 and had 10 fish (130-188 mm FL) as controls, which were 

 all held in 930 liter containers with ambient flow-through 

 water from Great Bay. One mortality occurred in a tagged 

 fish on the first day after tagging and the remainder (96%) 

 survived for 30 days. Tag retention during this period was 

 1007. . In 1999, we tagged 16 fish ( 16-92 mm FL ) and had 6 

 control (77-101 mm) fish. There was no mortality after 45 

 days, in either group, and tag retention was 100%. At this 

 time a power failure in the seawater system caused some 

 mortality. The surviving 8 fish had 100% tag retention to 

 65 days when the experiment was terminated. 



' Rowe, P. M., K. W. Able and M. J. Miller. In review. Distribu- 

 tion, abundance and size of young-of-the-year bluefish [Pomato- 

 mus saltatrix) in ocean and estuarine habitats in southern New 

 Jersey during 1999-2000. 



