The first standardized, global assessment of these fishes, using Red List criteria, reveals threatened species needing protection.

No abstract

Age, growth rates, mortality, and length‐weight relationships were determined for red snappers Lutjanus campechanus from two areas in the west central Atlantic Ocean and two in the northern Gulf of Mexico. Growth rates varied only slightly among areas. The von Bertalanffy growth equation was Lt = 975(1 ‐ e−0.16(t‐0.0)) for fish from the Atlantic and Lt = 941(1 ‐ e− 0.17(t + 0.1)) for fish from the Gulf of Mexico, where Lt is length at age t in years. The length‐weight equation differed among areas, but no difference was evident between sexes. This equation for fish from all areas pooled was W = 2.04 × 10−5TL2.953, where W is weight in grams and TL is total length in mm. Significant differences were found in total instantaneous mortality rates. The rate ranged from 0.39 for fish off the coast of North Carolina and South Carolina to 0.78 for fish off the coast of Louisiana. Age of full recruitment to the fishery ranged from 2 years off Louisiana to 6 years off the Carolinas. Fishing mortality appears to be the major cause of differences in total mortality among areas.

A total of 2,134 little tunny Euthynnus alletteratus were examined. Specimens ranged from 172 to 885mm fork length (FL) and were captured by hook and line and seines off the southeastern United States and from the Gulf of Mexico in 1980 and 1981. Approximately 57% (1, 212) of the stomachs contained ingested materials consisting of 20, 742 individual items, displacing 62, 961ml, and representing over 100 different categories. Fishes occurred in 66.9% of the stomachs with food, invertebrates in 30.5%, and miscellaneous items (Sargassum, seagrasses, inorganics, etc.) in 11.3%. Little tunny feed primarily in coastal waters on fishes, such as sardines, scads, and anchovies, and invertebrates. In decreasing order of importance clupeids, engraulids, unidentifiable fish, carangids, squid, stomatopods, penaeids, diogenids, stromateids, and synodontids were the most important foods in the diet, based on the index of relative importance (IRI). Diets differed with fish size (4 size classes), area of collection (8 areas) and season (4 seasons). BrayCurtis similarity coefficients were used to compare the diet of little tunny with those of king mackerel Scomberomorus cavalla and Spanish mackerel S. maculatus collected from the same areas. Ge nerally, the little tunny diet was more similar to that of king mackerel than to that of Spanish mackerel. All three coastal pelagic predators fed extensively on clupeids, carangids, and squids. Small crustaceans were more important to the diet of little tunny, and engraulids were more fre quently eaten by Spanish mackerel.

The incidental catch of northern sea lions (Eumetopias jubatus) in the walleye pollock (Theragra chalcogramma) joint‐venture fishery in Shelikof Strait, Alaska, was studied during 1982–1984 to assess the nature and magnitude of the catch. Data were obtained by placing U.S. observers on foreign processing vessels. Dead sea lions recovered from trawl nets were counted, sexed and measured, teeth were removed for age determination by dental laminae; and stomach contents were analyzed. Although the fishery has continued to expand both in number of boats and estimated total catch (74,136 metric tons [t] in 1982 to 171,539 t in 1984), the estimated incidental catch of northern sea lions has declined (ranging from 958 to 1,436 in 1982, 216 to 324 in 1983 and 237 to 355 in 1984). Of the sea lions processed, 73 percent were caught between 2000 and 0500 h, probably during net retrieval. Most caught sea lions were females ranging in age from 1–25 yr with a mean age of 6.43 yr; 79 percent of the females were sexually mature and probably part of the reproducing population. Males had a mean age of 4.8 yr and only 12 percent were old enough to obtain and defend territories. Analysis of stomach contents showed that the sea lions consumed pollock the same size as that taken by the commercial fishery. The impact of the incidental catch on the Gulf of Alaska sea lion population is unknown.