...of 15,699 bluefish were tagged by NMFS and 20,398 by ALS volunteers and 4.3% (1075 NMFS tags and 464 ALS tags) were recaptured and reported. Time-at-large was limited; 65.8% of the recaptured tags were returned within two months of tagging, although nineteen of the returned tags remained at large for two years or more. Tag returns indicated seasonal migrations of fish between the Middle Atlantic Bight and Florida. Three groups of bluefish are proposed for Atlantic coastal waters on the basis of tag return data and are defined by the seasonal occurrence of fish between 30 and 45 cm fork length. The northern group occupied the area from Massachusetts to Delaware between late spring and late fall. Bluefish in the central region between Maryland and North Carolina represented a combination of seasonal transient and resident fish, as did the southern group in Florida. Mixing occurs among all three groups; and larger fish (>45 cm) spend winters in offshore areas. Estimates of von Bertalanffy growth parameters from tagging data were comparable to scale-based estimates. Swimming speeds between point of release and recapture averaged 2.6 km per day, and seasonal spikes greater than 5 km per day corresponded with periods of migration in spring and autumn.

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Bluefish (Pomatomus saltatrix) is a pelagic species with a worldwide distribution in temperate and subtropical oceans. In the United States, bluefish are found along the Atlantic coast from southern Florida to Cape Cod, Massachusetts, and occasionally as far north as Nova Scotia (Collette and Klein-MacPhee, 2002). The broad-scale seasonal movements of bluefish are known within the commercial and recreational fishing communities (Hersey, 1987), but details of the migratory pattern remain poorly documented in the scientific literature. Tagging studies provide the most direct evidence of seasonal movements, but the only published account for the Atlantic coast stock is a study in Long Island Sound by Lund and Maltezos (1970). Wilk (1977) provided a description of bluefish migration that remains the accepted standard and which was based on seasonal distribution of commercial and recreational catches, as well as on unpublished results of a tagging project conducted during the 1960s by David Deuel and colleagues at the NMFS James. J. Howard Marine Sciences Laboratory (formerly known as the Sandy Hook Marine Laboratory). The proposed migration involved a north-south coastal movement between New York-New Jersey offshore waters and southeastern Florida offshore waters during the fall and a return spring migration along the same route. Larger fish (i.e. greater than three pounds) were believed to follow a more offshore pathway.

The identification of distinct bluefish stocks contributing to this migratory group has been the subject of multiple investigations. The racial composition of bluefish on the Atlantic coast was investigated by Lund (1961) who concluded, primarily from differences in the number of gill rakers of small bluefish, that six races existed along the coast. Lassiter (1962) found differences in first year growth on scales, which indicated that two groups of fish inhabited North Carolina waters. Returned tags from bluefish tagged in the Long Island area (Lund and Maltezos, 1970) also indicated two distinct stocks, although not necessarily the same groups as defined by Lassiter (1962). More recently, some scientists have concluded that either two distinct spawning groups exist (Norcross et al., 1974; Kendall and Walford, 1979) or one stock with two distinct survival periods (Hare and Cowen, 1993; Smith et al., 1994). Others, probing mitochondrial DNA (mtDNA) (Graves et al., 1993), have concluded that Atlantic coast bluefish constitute a single population. A discriminant function analysis of morphometric data has corroborated the one stock hypothesis despite evidence of phenotypically plastic characteristics (Austin et al., 1999).

Mark-recapture experiments provide an empirical method for evaluating both migratory behavior and stock composition. In 1962, the National Marine Fisheries Service (NMFS) initiated a study of the migratory patterns of bluefish to obtain information on the population structure of the Atlantic coast stock; this coastwide tagging program continued until 1967. The American Littoral Society (ALS) also coordinates an annual tagging program by private citizens that has resulted in 20 years of tag releases for a variety of species, including bluefish. This combined tag-recapture information constitutes the largest known tagging database for this species. The goal of our study was to investigate the migratory behavior of bluefish along the Atlantic coast by using the results of these previously unpublished tagging studies and to examine the single stock hypothesis in context of tag recovery information.

Materials and methods

The NMFS bluefish tagging program used several types of tags (variously colored). Field tests in 1963 indicated that a dorsal loop spaghetti tag would be more suitable, owing to a longer retention rate, than dart tags or jaw tags. This loop tag, described by Watson (1963), was closed with a pressure-fitted V-shaped clip. In addition, two other types of dorsal loop tags (both closed by knotting the ends of the tubing, and one having a clear outer covering) and an internal anchor tag (5/16 by 1-1/4 inches, with a 3" streamer as described by Topp [1963]) were used. For visibility of the tags to fishermen, orange was chosen as the color for most of the dorsal loop tags and yellow for the streamer of the internal anchor tags. The fork length of each fish tagged and released was measured to the nearest cm. Recapture information was mailed to NMFS in Sandy Hook, NJ, and included data on recapture location, recapture date, fish length (usually in inches), and weight (lbs and oz, when possible).

The ALS program uses yellow dorsal loop tags that are inserted with a hollow needle through the muscle below the dorsal fins and tied with a simple overhand knot or, as in some recent tags, fastened with a snap-lock mechanism (Carlsen, 2000). Details on the date, location of release, fork length (to the nearest inch), and weight (lbs and oz, when possible) were furnished by the fishermen at the time of release. Information regarding tag recapture (including location, recapture date, fish length [inch] and weight) was mailed to ALS headquarters by the...

NOTE: All illustrations and photos have been removed from this article.



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