Comparisons of Shark Catch Rates on Longlines Using Rope/Steel (Yankee) and Monofilament Gangions

During the months of June through September in 1991 and 1992, 71 shark longlines were fished in the Chesapeake Bight region ofthe U.S. mid-Atlantic coast with a combination of rope/steel (Yankee) and monofilament gangions. A total of 288 sharks were taken on 3,666 monofilament gangions, and 352 sharks were caught on 6,975 Yankee gangions. Catch rates between gear types differed by depth strata, by month, and by species. Analyses were divided between efforts in the nursery ground ofthe sandbar shark, Carcharhinus plumbeus, in Chesapeake Bay and efforts outside the Bay. Mean catch per unit effort (CPUE) ± SE, as sharks caught per 100 hooks fished, was significantly (P<0.05) lower for Yankee gangions. Mean CPUE's for sandbar sharks in the nursery ground were 20.6 ± 3.8 for Yankee gangions and 26.0 ± 3.0 for monofilament gangions, and mean CPUE's for all species combined outside the Bay were 3.7 ± 0.7 for Yankee gangions, and 6.9 ± 1.2 for monofilament gangions

Growth and maturity of salmon sharks (Lamna ditropis) in the eastern and western North Pacific, and comments on back-calculation methods

Age and growth estimates for salmon sharks (Lamna ditropis) in the eastern North Pacific were derived from 182 vertebral centra collected from sharks ranging in length from 62.2 to 213.4 cm pre-caudal length (PCL) and compared to previously published age and growth data for salmon sharks in the western North Pacific. Eastern North Pacific female and male salmon sharks were aged up to 20 and 17 years, respectively. Relative marginal increment (RMI) analysis showed that postnatal rings form annually between January and March. Von Bertalanffy growth parameters derived from vertebral length-at-age data are L∞ =207.4 cm PCL, k=0.17/yr, and t0=−2.3 years for females (n=166), and L∞ =182.8 cm PCL, k=0.23/yr , and t0=−1.9 years for males (n=16). Age at maturity was estimated to range from six to nine years for females (median pre-caudal length of 164.7 cm PCL) and from three to five years old for males (median precaudal length of 124.0 cm PCL). Weight-length relationships for females and males in the eastern North Pacific are W=8.2 × 10_05 × L2.759 –06 × L3.383 (r2 =0.99) and W=3.2 × 10 (r2 =0.99), respectively. Our results show that female and male salmon sharks in the eastern North Pacific possess a faster growth rate, reach sexual maturity earlier, and attain greater weight-at-length than their same-sex counterparts living in the western North Pacific

A Brief Interpretation of Summer Flounder, Paralichthys dentatus, Movements and Stock Structure with New Tagging Data on Juveniles

Summer flounder, Paralichthys dentatus, are managed as a single stock along the Atlantic coast from the U.S.– Canada border to the southern border of North Carolina. Justification of the single-stock approach is based on lack of genetic evidence for multiple stocks and the difficulty presented by managing the species from Cape Hatteras to the U.S.–Canada border. In this review, we present an interpretation of various morphometric, meristic, biochemical, and tagging studies, published and unpublished, that indicate the presence of two, or possibly three, distinct stocks in the management area. In addition, we have included new data from a tagging study that was conducted on juveniles from Virginia that aids in defining the stock(s) north of Cape Hatteras. Summer flounder, overfished for the past two decades, is recovering, and reconsideration of proposed stock structure could have direct implications for management policy decisions

Introduction: management of sharks and their relatives (Elasmobranchii)

This publication describes the scientific principles and techniques used for resource management of elasrnobranch fisheries with emphasis on the particular context of elasmobranchs. The management characteristics of these fishes are described - their common bycatch character and their biological constraints on productivity (low growth rate, late maturity and Tow fecundity). Stock assessment of elasrnobranchs is described in the context of rnanagement objectives in a wide management context. Special attention is given to accurate species identification given the prevalent aggregating of landings data across species, genera and often families in this group. Techniques and experiences for tagging elasmobranchs for population estimation are described as well as methods of genetic techniques for stock identification. Methods and problems involved in determining ,age, growth, fecundity and mortality rates are described and their use in age-structured models Within the context of the reproductive biology of these fishes. Demographic models to determine the productive of elasmobranch resources are described, Use of surveys to,complement information derived from fisheries is described together with management measures, Last, practices of shark utilization are noted.https://scholarworks.wm.edu/vimsbooks/1022/thumbnail.jp

Shark Utilization

Sharks and their relatives provide a multitude of usable products including: meat, fins, liver, skin, cartilage and jaws and teeth. Unfortunately, tens of millions of sharks taken in fisheries each year have their fins removed and their carcasses discarded overboard (Fowler and Musick, 2002). This practice, called finning, represents a considerable waste as the fins on average make up only about 5 % of the total weight of a shark (Vannuccini, 1999). Such waste is contrary to the United Nations Food and Agricultural Organization (FAO) Code of Conduct for Responsible Fisheries (Article 7.2.2 (g)) which stresses the importance of avoiding waste and discards in fisheries. In addition, the FAO International Plan of Action for the Conservation and Management of Sharks (IPOA- Sharks) encourages full use of dead sharks and retention of sharks from which fins have been removed (paragraph 22). Therefore, this Section briefly reviews the wide spectrum of uses that may be afforded by elasmobranchs to encourage their more complete and effective use. For a more comprehensive review see Vannuccini (1999) wherein an entire volume (470 pages) is devoted to the subject. A strong word of caution is necessary here: full utilization of shark carcasses should not be used as a pretext to fish unsustainably (Camhi, 2002). The goal of this manual is to provide information necessary to lead to sustainable elasmobranch fisheries.https://scholarworks.wm.edu/vimsbooks/1023/thumbnail.jp

Community structure of fishes on the continental slope and rise off the middle Atlantic coast of the United States

Otter trawl cruises were conducted off the middle Atlantic coast of the U. S. from 1971 to 1975. More than 50,000 specimens of demersal fishes were captured during this program at depths of 75 m to 3000 m. Species assemblages were distributed along a coenocline with bathymetric areas of rapid faunal change (anantoclines) and of more gradual faunal change (aganoclines). Between 75 and 3000 m anantoclines were found at 150 to 200 m, 400 to 600 m, 900 to 1000 m, 1350 to 1500 m, and 1900 to 2100 m. Species diversity (Hl) increased between the continental shelf and slope, remained constant to about 1800 m, then declined rapidly. This pattern was primarily related to species richness,not eveness. Numerical abundance increased bet~veen the shelf and slope, then declined exponentially. Biomass increased between the continental shelf and slope and then remained fairly constant out to a depth of about 1800 m beyond which there was an exponential decline (but not as steep as that for numerical abundance). The average size of fishes was about the same on the shelf and upperslope out to a depth of about 1800 m beyond which size increased by threefold. This size increase is contrary to that found for the meiofauna and macrofauna. The difference in strategies lies in the mobility of fishes which allows them to maintain viable sexually reproducing populations at relatively small population size. Biomass of fishes was of the same order of magnitude as that reported by other workers for the infauna at similar depths. This apparent contradiction of classic trophic pyramid structure is resolved because the mobility of fishes allows them to utilize pelagic as well as benthic food sources. The declines in diversity and biomass and the increase in average size of fishes, all occurred at around 1800 m near the slope-rise border beyond which regular food sources of continental origin are absent

Summary of Sea Turtle Research in Virginia During 1979 and 1980: final report for NMFS contract #80 FAC 00004

Directed research on the status of sea turtles in Virginia has been carried out by VIMS personnel since May 1979. Our efforts in 1979 (supported in-house) primarily comprised a documentation of sea turtle mortalities in the state. This. work was expanded somewhat in 1980 thru a small Fellowship Stipend from N.M.F.S, to support the thesis work of Molly Lutcavage. In 1980 Molly analyzed the 1979 mortality data, continued to monitor strandings, and began a tagging program in cooperation with selected poundnet fishermen. Also in 1980 we began an evaluation of sea turtle nesting in Virginia with the support of another Fellowship stipend from the City of Danville Virginia and E.P.A. awarded to Richard Byles. I will provide a brief summary of each of these sub-projects