Feeding Habits of the Common Thresher Shark (Alopias Vulpinus) Sampled from the California-Based Drift Gill Net Fishery, 1998-1 999

Total Page:16

File Type:pdf, Size:1020Kb

Feeding Habits of the Common Thresher Shark (Alopias Vulpinus) Sampled from the California-Based Drift Gill Net Fishery, 1998-1 999 PRETI ET AL.: FEEDING HABITS OF COMMON THRESHER SHARK CalCOFl Rep., Vol. 42, 2001 FEEDING HABITS OF THE COMMON THRESHER SHARK (ALOPIAS VULPINUS) SAMPLED FROM THE CALIFORNIA-BASED DRIFT GILL NET FISHERY, 1998-1 999 ANTONELLA PRETI SUSAN E. SMITH AND DARLENE A. RAMON California Department of Fish and Game National Marine Fisheries Service, NOM 8604 La Jolla Shores Dnve Southwest Fisheries Science Center La Jolla, California 92037 P.O. Box 271 sharksharkshark@hotniail coni La Jolla, California 92038 ABSTRACT (Compagno 1984). It is epipelagic, gregarious, and cos- The diet of common thresher shark (Alopius vulpinus) mopolitan, and in the northeastern Pacific seems to be from US. Pacific Coast waters was investigated by means most abundant within 40 miles of shore (Strasburg 1958). of frequency of occurrence, gravimetric and numerical Its known range extends from Clarion Island, Mexico, methods, and calculating the geometric index of im- north to British Columbia; it is common seasonally from portance (GII) of prey taxa taken from stoniachs col- mid-Baja California, Mexico, to Washington state.' It lected by fishery observers from the California-based is the leading commercial shark taken in California, drift gill net fishery. Sampling was done from 16 August where it is highly valued in the fresh fish trade (Holts et 1998 to 24 January 1999, a time when the California al. 1998). It is also sought by recreational anglers for its Current was undergoing rapid change from El Niiio to fighting ability as well as food value, especially in south- La Niiia conhtions. Of the 165 stomachs examined, 107 ern California. Patterns of observed catches and results contained food representing a total of 20 taxa, revealing of limited tagging suggest that it undertakes a seasonal a broader trophic spectrum than previously reported for north-south migration along the Mexico-U.S. West this species. Of the identifiable items, northern anchovy Coast, moving northward in summer, then returning to (Engraulis mordax) was the most important in the diet waters off Mexico in winter (Hanan et al. 1993). (GI1 = 48.2), followed by Pacific hake (Merluccius pro- Anecdotal accounts identifying prey items of this shark ductus; GI1 = 31.2), Pacific mackerel (Scomber japonicus; are scattered throughout the literature, but no compre- GI1 = 24.8), and Pacific sardine (Savdinops sagax; GI1 = hensive study of food habits has been undertaken. In 9.2). Of the invertebrates, squid (Teuthoidea, including California, as in other parts of the world (e.g., Spain; Loligo opalescenr; GI1 = 6.3), and pelagic red crab Moreno et al. 1989), A. vulpinus frequently occur in as- (Pleuroncodes planipes; GI1 = 6.6), were also important, sociation with large schools of small fishes, and feed on especially numerically. For sharks collected north of 34% them near the surface, often slashing the water with their latitude, hake was the most important identifiable species whiplike tails, presumably to herd or disorient their prey. in the diet; northern anchovy was most important in According to Compagno (1984), this shark also feeds the south, but was not identified in stomachs collected on mackerels, bluefishes, clupeids, needlefishes, lancet- north of Point Conception. fishes, and lanternfishes, as well as squids, octopuses, pelagic crustaceans, and (rarely) seabirds. Although he INTRODUCTION provided no supporting data, Bedford (1992) reported The Pacific Fishery Management Council recently that, unlike other pelagic shark species off California, included the common thresher shark (Alopias vulpinus) the common thresher shark does not appear to be an as a management unit species within the U.S. West Coast opportunistic feeder, but rather feeds almost exclusively Highly Migratory Species Fishery Management Plan, on northern anchovy (Engvaulis mordax). California fish- now under development. This has prompted the need ermen have reported finding salmon in the stomachs of for biological information on life history, stock struc- large individuals (w. Rendernick, Monterey, Calif., pers. ture, feeding ecology, and essential habitat of this species comm. 2/28/98). In the eastern North Atlantic, Pascoe to better assess stock status and harvest impacts. To date, (1986) examined teleost otoliths from the stomach of a little has been documented on its habitat requirements, 264 kg female, and concluded that the stomach had orig- and only anecdotal accounts are available on its feeding inally contained at least 28 scad (Tvdchurus tr~churus),6 ecology off the U.S. West Coast. whiting (Merlangius merlungus), and a single mackerel The common thresher shark is a large, active, and (Scombev scombrus). strong-swimming shark that occurs in neritic and oceanic waters in subtropical and temperate seas worldwide 'Smith, S. E., R. C. Rasmussen, D. A. Ramon, and G. M. Cailliet. Biology and ecology of thresher sharks (fami1y:Alopiidae). In Sharks of the open ocean, E. [Manuscript received 4 February 2001 .] Pikitch and M. Camhi, eds. MS submitted to Blackwell Scientific Publications. 145 PRETI ET AL.: FEEDING HABITS OF COMMON THRESHER SHARK CalCOFl Rep., Vol. 42, 2001 We examined and analyzed the stomach contents of 4. Unmeasurable body parts only: parts cannot be re- common thresher shark collected by drift gill net ob- constructed to obtain standard measurements, but servers off California, and compared diets between higher taxon or species group still identifiable; size/age classes, seasons, and general catch locations. 5. Digested: identifiable only to a very general high- MATERIALS AND METHODS level taxon; and 6. Fully digested: unidentifiable material; slurry. Sampling at Sea Prey itenis were then separated, identified to lowest Stomach samples were collected from three common possible taxonomic level, and enumerated, measured (to thresher shark size groups by federal fishery observers nearest mm, standard length) and weighed (to the near- aboard commercial drift gill net vessels operating off est 0.1 g), when possible. Fish otoliths and squid beaks California and southern Oregon during the 1998-99 were counted in pairs, with the highest count repre- August through January fishing season. Because sampling senting the minimum number present. Weights were time and freezer space are limited aboard these vessels, recorded by taxon groups (not individually), while lengths and to maximize sampling for small fish in the under- of all intact individuals within a taxon were measured. sampled inshore areas, observers were instructed to col- Content data were pooled for all stomachs (all strata lect stoniachs according to the following protocol: combined) and analyzed by prey taxa for relative mea- 1. size group = <100 cni fork length (up to -200 cni sures of prey quantity (RMPQs) as follows: percent nu- total length, or young-of-year), up to 10 stomachs meric occurrence ("/,A?, percent weight (o/oLV'), and per trip;' percent frequency of occurrence ('XF) of food items. The value '%A' = the number of individuals of one prey 2. size group 101-160 cm FL (200-300 cm TL, or ju- taxon divided by the total number of all prey individu- veniles/subadults), up to 5 stomachs per trip; and als x 100; %W = weight of one prey taxon divided by 3. size group >160 cni FL (over about 300 cni TL, or total weight of all prey x 100; and %F = number of adults/large subadults), up to 5 stomachs per trip. stomachs containing prey of one taxon divided by total Samples were excised at sea; esophageal and pyloric number of stomachs that contained any prey items x 100. ends were secured with plastic cinch ties; and the stom- Empty stomachs and certain sinall incidentally ingested achs were bagged, labeled, and frozen. Data on set and organisms, slurry, and detritus were not used in calcu- haul time, water depth, sea-surface water temperature, lating percentages or indices. location, fish size, sex, and maturity state were recorded. Cumulative prey curves were constructed to deter- mine whether an adequate number of speciniens over- Processing in the Laboratory all or in subsamples had been collected to describe diet Stomach samples were thawed, tamped with absorbent (e.g., Hurtubia 1973; Cailliet et al. 1986; Gelsleichter et paper to remove excess water, and weighed full. Contents al. 1999; Yaniaguchi and Taniuchi 2000). The order in were then removed, and the empty stomach was weighed which stoniachs were analyzed was randomized 10 times, to determine the overall weight of the contents. Materials and the mean number of new prey species was cuniu- and slurry were rinsed and sorted with a series of screen lated consecutively in order of the stomachs examined. sieves with mesh sizes 9.5 iiini, 1.4 nini, and 0.5 niin In this type of sample-size analysis, presence of an asymp- for ease in rinsing inidsized food boluses without losing totic relationship indicates that the number of stomachs some of the smallest items, such as fish otoliths. analyzed is sufficient to represent the diet of a particu- Percentage of stomach fullness (0-1 00%) was estimated lar predator, and that enlargement of the sample beyond visually as a broad gauge of relative fullness. The degree the point of curve stabilization would cause no further of prey digestion was estimated as follows: increase in trophic diversity (Hurtubia 1973). 1. Fresh: head, body, shn, and most fins intact, although Measure of prey quantity (RMPQ) values were used some individuals may be in pieces (i.e., bitten on to calculate the geometric index of iniportance (GII), capture) ; as developed by Assis
Recommended publications
  • Breeding in an Oceanic Population of Pleuroncodes Planipes (Crustacea, Galatheidae) 1 ALAN R
    Breeding in an Oceanic Population of Pleuroncodes planipes (Crustacea, Galatheidae) 1 ALAN R. LONGHURST2 AND DON L. R. SEIBERT'l ABSTRACT: The pelagic population of Pleuroncodes planipes known to occur in the California Current Extension is partly recruited by drift of megalopas from neritic regions and partly, as demonstrated by EASTROPAC samples, by breeding in situ , THE DISTRIBUTION of pelagic adults and larvae samples; only size frequencies of night samples of the galatheid crab Pleuroncodes planipes in are used here. the California Current has been described re­ Adults of Pleuroncodes planipes, none of cently (Boyd, 1963, 1967; Longhurst, 1967, which had carapace lengths exceeding 15 mm, 1968). These studies showed the regular occur­ were found early in the year in northern Area 1. rence of an oceanic population of small adults This population (carapace length 9 to 13 mm) far beyond the normal neritic habitat and indi­ shifted its locus in late summer until, at the end cated how this expatriate population might be of the year, all occurrences were south of 14° recruited from megalopas derived from the N ; the second winter cruise (February-March neritic population along the west coast of Baja 1968) showed that the population had shifted California. north again to a locus between 14° to 20° N. The Eastern Tropical Pacific (EASTROPAC) In Area 2, adults were present only after Au­ expeditions (February 1967 to March 1968 gust-September, when a population of very from 20° N to 20° S and from the American small (6 to 8 mm) . adults appeared in the sam­ continent out to 126° W) afforded an oppor­ ples and remained through the end of the year.
    [Show full text]
  • HMS App a August 2003
    APPENDIX F U.S. WEST COAST HIGHLY MIGRATORY SPECIES: LIFE HISTORY ACCOUNTS AND ESSENTIAL FISH HABITAT DESCRIPTIONS (Originally Appendix A to the FMP) U.S. West Coast Highly Migratory Species Plan Development Team Pacific Fishery Management Council Originally Available January 16, 2003 HMS FMP - Appendix Fi June 2007 TABLE OF CONTENTS REVIEW OF METHODS AND DEFINITIONS.............................................F-1 1.0SHARKS ....................................................................F-1 1.1Common Thresher ...........................................................F-1 1.1.8 Essential Fish Habitat for Common Thresher ................................F-4 1.2Pelagic Thresher.............................................................F-5 1.2.8 Essential Fish Habitat for Pelagic Thresher..................................F-6 1.3Bigeye Thresher .............................................................F-7 1.3.8 Essential Fish Habitat for Bigeye Thresher ..................................F-9 1.4Shortfin Mako ...............................................................F-9 1.4.8 Essential Fish Habitat for Shortfin Mako ...................................F-12 1.5Blue Shark.................................................................F-12 1.5.8 Essential Fish Habitat for Blue Shark......................................F-16 2.0TUNAS.......................................................................F-16 2.1Albacore ..................................................................F-16 2.1.8 Essential Fish Habitat for Albacore .......................................F-20
    [Show full text]
  • Marine Fish Conservation Global Evidence for the Effects of Selected Interventions
    Marine Fish Conservation Global evidence for the effects of selected interventions Natasha Taylor, Leo J. Clarke, Khatija Alliji, Chris Barrett, Rosslyn McIntyre, Rebecca0 K. Smith & William J. Sutherland CONSERVATION EVIDENCE SERIES SYNOPSES Marine Fish Conservation Global evidence for the effects of selected interventions Natasha Taylor, Leo J. Clarke, Khatija Alliji, Chris Barrett, Rosslyn McIntyre, Rebecca K. Smith and William J. Sutherland Conservation Evidence Series Synopses 1 Copyright © 2021 William J. Sutherland This work is licensed under a Creative Commons Attribution 4.0 International license (CC BY 4.0). This license allows you to share, copy, distribute and transmit the work; to adapt the work and to make commercial use of the work providing attribution is made to the authors (but not in any way that suggests that they endorse you or your use of the work). Attribution should include the following information: Taylor, N., Clarke, L.J., Alliji, K., Barrett, C., McIntyre, R., Smith, R.K., and Sutherland, W.J. (2021) Marine Fish Conservation: Global Evidence for the Effects of Selected Interventions. Synopses of Conservation Evidence Series. University of Cambridge, Cambridge, UK. Further details about CC BY licenses are available at https://creativecommons.org/licenses/by/4.0/ Cover image: Circling fish in the waters of the Halmahera Sea (Pacific Ocean) off the Raja Ampat Islands, Indonesia, by Leslie Burkhalter. Digital material and resources associated with this synopsis are available at https://www.conservationevidence.com/
    [Show full text]
  • The Pelagic Phase of Pleuroncodes Planipes Stimpson (Crustacea, Galatheidae) in the California Current
    THE PELAGIC PHASE OF PLEURONCODES PLANIPES STIMPSON (CRUSTACEA, GALATHEIDAE) IN THE CALIFORNIA CURRENT ALAN R. LONGHURST' Institute of Marine Resources and Scripps Institution of Oceanography La Jolla, California INTRODUCTION 140 meters with a 1-meter zooplankton net; details of the sampling procedure and of the location of sta­ The planktonic habit may be prolonged into or re­ tions are described elsewhere (e.g. Ahlstrom, 1948; cur in the adults of two species of Galatheidae. Harri­ son Matthews (1932) uses the terms "lobster-krill" CalCOFI, 1963). or "whale feed" in reference to these: Munida gre- The data consist of records of the numbers of garia (Fabricus) of southern South America and pelagic crabs removed in the laboratory from each of New Zealand, and Pleuroncodes planipes Stimpson zooplankton sample before voluming, and these num­ the red or pelagic crab of California and Mexico. bers were extracted for the present study from the Both occur at times as conspicuous concentrations of original data sheets. The actual specimens had neither apparently adult crabs on which baleen whales are been measured nor were subsequently retained except known to browse (Harrison Matthews, 1932) ; in addi­ during 8 months of 1960 when the whole catch of tion, the studies of Me Hugh (1952) and Alverson pelagic crabs was measured by Boyd (1963) who (1963) on the tuna Thunnus alalunga, Katsuwonus recorded a range in standard carapace length of from pelamis and Thunnus albacares have shown that 7 to 20 mm; it has been assumed here that the Cal­ Pleuroncodes is a significant food item during their COFI data to be discussed refer only to subadult and summer migration into the California Current; for adult crabs within this size range.
    [Show full text]
  • Fish Bulletin 152. Food Habits of Albacore, Bluefin Tuna, and Bonito in California Waters
    UC San Diego Fish Bulletin Title Fish Bulletin 152. Food Habits of Albacore, Bluefin Tuna, and Bonito In California Waters Permalink https://escholarship.org/uc/item/7t5868rd Authors Pinkas, Leo Oliphant, Malcolm S Iverson, Ingrid L.K. Publication Date 1970-06-01 eScholarship.org Powered by the California Digital Library University of California STATE OF CALIFORNIA THE RESOURCES AGENCY DEPARTMENT OF FISH AND GAME FISH BULLETIN 152 Food Habits of Albacore, Bluefin Tuna, and Bonito In California Waters By Leo Pinkas , Malcolm S. Oliphant, and Ingrid L. K. Iverson 1971 1 2 ABSTRACT The authors investigated food habits of albacore, Thunnus alalunga, bluefin tuna, Thunnus thynnus, and bonito, Sarda chiliensis, in the eastern North Pacific Ocean during 1968 and 1969. While most stomach samples came from fish caught commercially off southern California and Baja California, some came from fish taken in central Califor- nia, Oregon, and Washington waters. Standard procedures included enumeration of food items, volumetric analysis, and measure of frequency of occur- rence. The authors identified the majority of forage organisms to the specific level through usual taxonomic methods for whole animals. Identification of partially digested animals was accomplished through the use of otoliths for fish, beaks for cephalopods, and the exoskeleton for invertebrates. A pictorial guide to beaks of certain eastern Pacific cephalopods was prepared and proved helpful in identifying stomach contents. This guide is presented in this publication. The study indicates the prominent forage for bluefin tuna, bonito, and albacore in California waters is the northern anchovy, Engraulis mordax. 3 ACKNOWLEDGMENTS The Food Habits Study of Organisms of the California Current System, (Project 6–7-R), was an investigation estab- lished under contract between the U.S.
    [Show full text]
  • Forage Fish Management Plan
    Oregon Forage Fish Management Plan November 19, 2016 Oregon Department of Fish and Wildlife Marine Resources Program 2040 SE Marine Science Drive Newport, OR 97365 (541) 867-4741 http://www.dfw.state.or.us/MRP/ Oregon Department of Fish & Wildlife 1 Table of Contents Executive Summary ....................................................................................................................................... 4 Introduction .................................................................................................................................................. 6 Purpose and Need ..................................................................................................................................... 6 Federal action to protect Forage Fish (2016)............................................................................................ 7 The Oregon Marine Fisheries Management Plan Framework .................................................................. 7 Relationship to Other State Policies ......................................................................................................... 7 Public Process Developing this Plan .......................................................................................................... 8 How this Document is Organized .............................................................................................................. 8 A. Resource Analysis ....................................................................................................................................
    [Show full text]
  • Plastic and Evolutionary Responses to Climate Change in Fish
    Evolutionary Applications Evolutionary Applications ISSN 1752-4571 REVIEWS AND SYNTHESIS Plastic and evolutionary responses to climate change in fish Lisa G. Crozier1 and Jeffrey A. Hutchings2,3 1 Northwest Fisheries Science Center, Seattle, WA, USA 2 Department of Biology, Dalhousie University, Halifax, NS, Canada 3 Department of Biosciences, Centre for Ecological and Evolutionary Synthesis, University of Oslo, Oslo, Norway Keywords Abstract adaptation, climate change, evolutionary theory, fisheries management, life-history The physical and ecological ‘fingerprints’ of anthropogenic climate change over evolution, phenotypic plasticity the past century are now well documented in many environments and taxa. We reviewed the evidence for phenotypic responses to recent climate change in fish. Correspondence Changes in the timing of migration and reproduction, age at maturity, age at Lisa G. Crozier, Northwest Fisheries Science juvenile migration, growth, survival and fecundity were associated primarily with Center, 2725 Montlake Blvd E., Seattle, WA changes in temperature. Although these traits can evolve rapidly, only two studies 98112, USA. Tel.: +1 206 860 3395 attributed phenotypic changes formally to evolutionary mechanisms. The correla- fax: +1 206 860 3267 tion-based methods most frequently employed point largely to ‘fine-grained’ e-mail: [email protected] population responses to environmental variability (i.e. rapid phenotypic changes relative to generation time), consistent with plastic mechanisms. Ultimately, Received: 10 May 2013
    [Show full text]
  • 4 Thresher Shark, Alopias Vulpinus
    4 Thresher Shark, Alopias vulpinus Thresher shark, Alopias vulpinus. Photo credit: Dale Sweetnam. History of the Fishery The common thresher shark, Alopias vulpinus, is the most common commercially landed shark in California. They are primarily caught using large mesh drift gill nets and hook and line gear, but are also caught incidentally with small mesh gill nets and harpoon. Prior to 1977, all sharks were reported in one market category and not separated by species, and it is assumed threshers were caught as bycatch in gears at levels similar or greater than today. The first significant fishery for thresher sharks began the late 1970s to early 1980s when drift gill net fishers began to target them close to the southern California coastline. The fishery expanded rapidly and, because of overfishing concerns, the California Department of Fish and Game (Department) as mandated by the State Legislature began an observer program, monitored landings and implemented a logbook program. A limited entry permit program for drift gill net gear was initiated in 1982, with permits issued to fishers rather than boats to prevent false inflation in value. The drift gill net fishery for thresher sharks peaked in 1981 when 113 Status of the Fisheries Report 2008 4-1 drift gill net boats landed nearly 600 tons (544 metric tons). However, total landings using all gears were highest the following year with a total of more than 1700 tons (1542 metric tons) taken by all gears (Figure 4-1). 2000 1500 1000 Landings (short tons) (short Landings 500 0 1977 1979 1981 1983 1985 1987 1989 1991 1993 1995 1997 1999 2001 2003 2005 2007 Year Figure 4-1.
    [Show full text]
  • The Denticle Surface of Thresher Shark Tails: Three-Dimensional Structure and Comparison to Other Pelagic Species
    Received: 3 April 2020 Revised: 14 May 2020 Accepted: 21 May 2020 DOI: 10.1002/jmor.21222 RESEARCH ARTICLE The denticle surface of thresher shark tails: Three-dimensional structure and comparison to other pelagic species Meagan Popp1 | Connor F. White1 | Diego Bernal2 | Dylan K. Wainwright1 | George V. Lauder1 1Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, Abstract Massachusetts Shark skin denticles (scales) are diverse in morphology both among species and 2 Department of Biology, University of across the body of single individuals, although the function of this diversity is poorly Massachusetts Dartmouth, Dartmouth, Massachusetts understood. The extremely elongate and highly flexible tail of thresher sharks pro- vides an opportunity to characterize gradients in denticle surface characteristics Correspondence George V. Lauder, Museum of Comparative along the length of the tail and assess correlations between denticle morphology and Zoology, 26 Oxford Street, Cambridge, MA tail kinematics. We measured denticle morphology on the caudal fin of three mature 02138. Email: [email protected] and two embryo common thresher sharks (Alopias vulpinus), and we compared thresher tail denticles to those of eleven other shark species. Using surface Funding information National Oceanic and Atmospheric profilometry, we quantified 3D-denticle patterning and texture along the tail of Administration, Grant/Award Number: threshers (27 regions in adults, and 16 regions in embryos). We report that tails of NA16NMF4270231; National Science Foundation, Grant/Award Numbers: IOS- thresher embryos have a membrane that covers the denticles and reduces surface 1354593, GRF DGE-1144152; Office of Naval roughness. In mature thresher tails, surfaces have an average roughness of 5.6 μm Research, Grant/Award Numbers: N00014-09-1-0352, N000141410533 which is smoother than some other pelagic shark species, but similar in roughness to blacktip, porbeagle, and bonnethead shark tails.
    [Show full text]
  • Use of Productivity and Susceptibility Indices to Determine the Vulnerability of a Stock: with Example Applications to Six U.S
    Use of productivity and susceptibility indices to determine the vulnerability of a stock: with example applications to six U.S. fisheries. Wesley S. Patrick1, Paul Spencer2, Olav Ormseth2, Jason Cope3, John Field4, Donald Kobayashi5, Todd Gedamke6, Enric Cortés7, Keith Bigelow5, William Overholtz8, Jason Link8, and Peter Lawson9. 1NOAA, National Marine Fisheries Service, Office of Sustainable Fisheries, 1315 East- West Highway, Silver Spring, MD 20910; 2 NOAA, National Marine Fisheries Service, Alaska Fisheries Science Center, 7600 Sand Point Way, Seattle, WA 98115; 3NOAA, National Marine Fisheries Service, Northwest Fisheries Science Center, 2725 Montlake Boulevard East, Seattle, WA 98112; 4NOAA, National Marine Fisheries Service, Southwest Fisheries Science Center, 110 Shaffer Road, Santa Cruz, CA 95060; 5NOAA, National Marine Fisheries Service, Pacific Islands Fisheries Science Center, 2570 Dole Street, Honolulu, HI 96822; 6NOAA, National Marine Fisheries Service, Southeast Fisheries Science Center, 75 Virginia Beach Drive, Miami, FL 33149; 7NOAA, National Marine Fisheries Service, Southeast Fisheries Science Center, 3500 Delwood Beach Road, Panama City, FL 32408; 8NOAA, National Marine Fisheries Service, Northeast Fisheries Science Center, 166 Water Street, Woods Hole, MA 02543; 9NOAA, National Marine Fisheries Service, Northwest Fisheries Science Center, 2030 South Marine Science Drive, Newport, OR 97365. CORRESPONDING AUTHOR: Wesley S. Patrick, NOAA, National Marine Fisheries Service, Office of Sustainable Fisheries, 1315 East-West
    [Show full text]
  • Diet of Oceanic Loggerhead Sea Turtles (Caretta Caretta) in the Central North Pacific
    Diet of oceanic loggerhead sea turtles (Caretta caretta) in the central North Pacific Item Type article Authors Parker, Denise M.; Cooke, William J.; Balazs, George H. Download date 29/09/2021 11:03:34 Link to Item http://hdl.handle.net/1834/26255 ART & EQUATIONS ARE LINKED Preflight Good 142 Abstract — Diet analysis of 52 log- gerhead sea turtles (Caretta caretta) Diet of oceanic loggerhead sea turtles collected as bycatch from 1990 to 1992 (Caretta caretta) in the central North Pacific in the high-seas driftnet fishery oper- ating between lat. 29.5°N and 43°N and between long. 150°E and 154°W Denise M. Parker demonstrated that these turtles fed Joint Institute for Marine and Atmospheric Research predominately at the surface; few 8604 La Jolla Shores Drive deeper water prey items were pres- La Jolla, California 92037 ent in their stomachs. The turtles Present address: Northwest Fisheries Science Center ranged in size from 13.5 to 74.0 cm National Marine Fisheries Service, NOAA curved carapace length. Whole tur- Newport, Oregon 97365-5275 tles (n=10) and excised stomachs E-mail address: [email protected] (n=42) were frozen and transported to a laboratory for analysis of major faunal components. Neustonic species William J. Cooke accounted for four of the five most AECOS, Inc. common prey taxa. The most common 970 N. Kalaheo Avenue, Suite C311 prey items were Janthina spp. (Gas- Kailua, Hawaii 96734 tropoda); Carinaria cithara Benson 1835 (Heteropoda); a chondrophore, Velella velella (Hydrodia); Lepas spp. George H. Balazs (Cirripedia), Planes spp. (Decapoda: Pacific Islands Fisheries Science Center, Honolulu Laboratory Grapsidae), and pyrosomas (Pyrosoma National Marine Fisheries Service spp.).
    [Show full text]
  • Profiles of Whiting (Merlangius Merlangus Euxinus Nordman, 1840) Meat and Roe During Fishing Season in Black Sea
    ─── Food Technology ─── Comparison of fatty acids, lipid quality index and amino acid profiles of whiting (Merlangius merlangus euxinus Nordman, 1840) meat and roe during fishing season in Black Sea Demet Kocatepe, Can Okan Altan, Hülya Turan Sinop University, Sinop, Turkey Abstract Keywords: Introduction. The aim of research is to determine the fatty Whiting acid and amino acid composition of the whiting meat and roe Fish roe caught in different months in Black Sea. Amino acids Materials and methods. The whiting (Merlangius Fatty acids merlangus euxinus Nordman, 1840) caught from the Sinop EPA region of the Middle Black Sea Region. Sampling were carried DHA out twice a month. And the whiting meat and roe were compared in view of its fatty acid (FA) and amino acid (AA) composition during fishing season in Black Sea. Results and discussion. During the six months, the length and weight of whiting used in the study varied between 14.15– 16.60 cm and 24.49–29.68 g, respectively. Minimum length Article history: and weight were determined in March. Maximum crude protein values of fish meat and roes was determined in May Received 21.12.2018 Received in revised (18.61g/100g) and in April (16.30g/100g), respectively. SFA’s form 03.05.2019 (saturated fatty acids), MUFA’s (monounsaturated fatty acids) Accepted 30.09.2019 and PUFA’s (polyunsaturated fatty acids) of fish meat and roes had been varied during the season. The minimum and maximum EPA, DHA contents were found as 7.42–10.72, Corresponding 3.39–22.67g/100g in meat and 0.03-0.37, 3.79–4.76 g/100g in author: roe, respectively.
    [Show full text]