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Twenty giant bluefin tuna were captured in September and October 1997 and tagged and released with pop-up satellite tags programmed to jettison from March through July, 1998. Seventeen tags successfully released from the fish (12 during the known May-July spawning period), all of which were located north of 33°N latitude, in a region of the mid-Atlantic bounded by Bermuda and the Azores. Our results argue for reconsideration of current assumptions about North Atlantic bluefin tuna migration patterns, mixing rates, spawning areas, and stock structure and highlight the need for additional studies.

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Abstract. Knowledge of relationships between predator size and prey size are needed to describe interactions of species and size classes in food webs. Most estimates of predator and prey sizes have been based on dietary studies and apply to small numbers of species in a relatively narrow size range. These estimates may or may not be representative of values for other groups of species and body sizes or for other locations. Marine predator and prey size data associated with published literature were identified and collated to produce a single data set. If predator or prey length of mass were not measured in the original study, the length or mass was calculated using length-mass relationships. The data set consists of 34 931 records from 27 locations covering a wide range of environmental conditions from the tropics to the poles and for 93 types of predator with sizes ranging from 0.1 mg to over 415 kg and 174 prey types with sizes from 75 pg to over 4.5 kg. Each record includes: predator and prey scientific names, common names, taxa, life stages and sizes (length and mass with conversion details), plus the type of feeding interaction, geographic location (with habitat description, latitude, longitude) and mean annual environmental data (sea surface temperature and primary productivity).

Stomach contents of striped bass (Morone saxatilis) collected from three coastal regions of Massachusetts during JuneSeptember in 19972000 were examined for patterns in prey composition and body size related to coastal region, time period of capture, foraging habitat, and length of striped bass. Together fish (mostly Clupeidae, Menidia sp., and Ammodytes sp.) and crustaceans (mostly Crangon septemspinosa, Cancer irroratus, and Homarus americanus) dominated the diet of striped bass by both weight (9195%) and number (8797%), and had a high frequency of occurrence (4266%) in the stomachs. Similarity in prey taxa among coastal regions was moderate to high (5874%). Cluster analysis and ordination techniques grouped the stomach contents from each region by capture period, habitat, and 50 mm striped bass length interval. The stomach contents of bass <675 mm total length (TL) collected during August September from estuaries and rocky shoreline habitats in the North Shore and Cape Cod Bay regions had a higher average percentage of menhaden (Brevoortia tyrannus) by weight than found in similar-sized bass collected during JuneJuly from the same habitats. Also, in the North Shore area, striped bass <675 mm TL sampled in rocky shorelines contained a higher average percentage of Cancer irroratus by weight than similar-sized bass taken in estuaries. Bass >675 mm TL in rocky habitats consumed more Homarus americanus than smaller bass residing in this same habitat. The size distribution of the dominant fishes and crabs (Ammodytes sp., B. tyrannus, Cancer irroratus, and Carcinus maenus) consumed by striped bass was related to bass body size. Benthic prey were found to be a major component of the diet of striped bass in Massachusetts coastal waters.