Fisheries science
Print ISSN : 0919-9268
Volume 68 , Issue sup1
Showing 1-50 articles out of 282 articles from the selected issue
  • I CHIU LIAO
    2002 Volume 68 Issue sup1 Pages 3-13
    Published: 2002
    Released: June 30, 2008
    JOURNALS FREE ACCESS
    Asia is the largest continent in the world. Asians comprise 60% of the world's current population of 6.1 billion. Since ancient times, most Asians have relied on fish and other aquatic foods as a major source of animal protein. At the end of the 1990 s, a full two-thirds of the world annual food fish production, 93 million metric tons, were consumed in Asia. The vast aquatic resources in the region coupled with aquaculture history which spans for millennia have predisposed the Asians to be predominantly seafood consumers. In 1999, aquaculture and capture fisheries production in the region constituted 91% and 49% by weight, respectively, of the total world production. The top ten aquaculture producers and five of the top ten capture fisheries producers were from Asia.
    The substantial increase in aquaculture production may principally be attributed to the significant advances in fisheries science over the past century. The biology of many aquatic organisms has been understood more extensively and, accordingly, led to the development of modern aquaculture technologies. On the other hand, the nature of capture fisheries resources has also become better comprehended. For instance, the idea that the seas and oceans are inexhaustible has been shown untenable. At the present, however, Asian fisheries are at considerable danger mainly due to environmental degradation and overexploitation. The recognition of the fragility of both aquaculture and capture fisheries resources, and the efforts to ensure their sustainability, may perhaps be the best outcomes so far from the advances made in the field of fisheries science not only in Asia but throughout the world. Under this current scenario, making use of the advances in fisheries science is even more crucial.
    Most recent advances in fisheries sciences are broad in scope and multi-disciplinary in nature, taking advantage of the rapid developments in physical sciences, molecular biology and information technology. Furthermore, socio-cultural and economic concerns are being given due attention. There is, therefore, sufficient knowledge that can be applied to ensure that Asia continues to utilize its capture fisheries and aquaculture resources. To achieve these objectives, a brief layout of the comprehensive set of strategies is presented to include continuous innovations in aquaculture technology, implementation of relevant management techniques and regulations, and strengthening of regional and international cooperation. It is critical at this time to implement these strategies based on the current knowledge or it will be too late. From the trends in capture fisheries and aquaculture in the past century, it has become apparent that the fundamental roles and contributions of fisheries science are vital for the well-being of future generations in the 21st century and further.
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  • CARL BURGER
    2002 Volume 68 Issue sup1 Pages 14-19
    Published: 2002
    Released: June 30, 2008
    JOURNALS FREE ACCESS
    World fisheries yield 90 million metric tons of fish per year (over 70% of the world's commercial fish production) and play key roles in global food and income. Marine fisheries have long been driven by single-species management strategies in attempts to maximize yields without compromising future catches. However, single-species approaches overlook ecological linkages and interactions, and the ability of marine environments to sustain multi-species fisheries. Hence, some populations have been fished to collapse and others have become economically inefficient, often with consequences for non-target populations. Our science and management must operate in harmony with established ecological principles, if we are to conserve fisheries and avoid the declines of the past. Fishery professionals must also harmonize approaches for solving ecosystem-level problems. Most importantly, we must be willing to consider new approaches that (1) improve our capabilities and skills in multidisciplinary fisheries science, and (2) embrace new conservation paradigms that involve fishers and avoid managing species as if they existed in a vacuum. The recently revived World Council of Fisheries Societies can be a key global voice for helping implement such visions, and for uniting our professionals, fishers, and policymakers in ways that promote healthy world fisheries in the 21 st century.
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  • SHIGENOBU TAKEDA
    2002 Volume 68 Issue sup1 Pages 20-24
    Published: 2002
    Released: June 30, 2008
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    Effective utilization of large potential productivity of the ocean's renewable biological resources is important for pursuing sustainable development of marine environment. The biological productivity and fisheries harvest of the ocean is dependent on net primary production, which could be limited by availability of macronutrients or, in some open-ocean region, micronutrients such as iron. Understanding the regulatory mechanisms of the primary production in global marine ecosystems is essential to assess the feasibility of increasing the ocean harvest. Experimental approach such as the in situ iron enrichment experiment seems to be a strong tool to test the hypothesis on relationship between primary production and fish production. Using the ocean as a laboratory we can accumulate the knowledge of the ocean's global metabolism, which helps to ensure harmonious coexistence between nature and human beings.
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  • KOJI MAEKAWA, SHIGERU NAKANO
    2002 Volume 68 Issue sup1 Pages 27-32
    Published: 2002
    Released: June 30, 2008
    JOURNALS FREE ACCESS
    Since many salmonid species have the alternative life history strategies, they provide us a good opportunity to solve such a riddle. In a model, the anadromous life history of salmon may not be an evolutionarily stable state. If the gain in fitness from staying in a river exceeds the fitness from the sea, the fluvial life history can occur or vice versa. Some data may support these predictions. The relative reproductive success of migratory and fluvial females has latitudinal variation (so called geocline); the latter will be higher at the southern limits of the ranges, and conversely, the former will have higher fitness at the northern part, probably supporting the food availability hypothesis.
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  • SATOSHI KATAYAMA
    2002 Volume 68 Issue sup1 Pages 33-36
    Published: 2002
    Released: June 30, 2008
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    Pond smelt, Hypomesus nipponensis, inhabit fresh, brackish, and oceanic waters, and support substantial commercial fisheries in Japanese lakes. Pond smelt in Lake Ogawara, northern Japan, display a bimodal body length distribution during the spawning season, despite being O+ fish. Analyses of otolith microstructure and microchemistry were utilized to discriminate anadromous from resident individuals, and revealed that individuals smaller than 60 mm SL were resident, those between 60-80 mm were mixed resident and anadromous, and those larger than 80 mm were anadromous. Intensive research on the reproductive ecology identified spawning localities in the lake and inflowing rivers. Although only anadromous fish spawned in inflowing rivers, spawners in the lake were a mixture of anadromous and resident individuals, suggesting that anadromous and resident spawning groups share a common spawning ground. These fish spawn during almost the same period from mid March to early May. Therefore, reproductive isolation does not appear to occur, and genetic differentiation has not been found through isozyme and mtDNA analyses. The anadromous and resident life history styles appear to be ecological variations within a single population. Lastly, qualitative and quantitative contributions of migratory and non-migratory pond smelts to the next generation were examined and heterogeneity in the life history of this population was discussed.
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  • MICHAEL J. MILLER
    2002 Volume 68 Issue sup1 Pages 37-40
    Published: 2002
    Released: June 30, 2008
    JOURNALS FREE ACCESS
    Eels of the order Anguilliformes are very diverse in their behavior and in the habitats they use, but all species spawn in the ocean and have a leptocephalus larva, The catadromous eels of the Anguillidae are famous for making long spawing migrations from freshwater to the open ocean. In contrast, recent studies of tropical anguillids indicate that they appear to have much shorter spawning migrations and potentially year-round spawning. However, the most widespread tropical eel, Anguilla marmorata, appears to have a northern subpopulation that has a spawning migration similar to the temperate species Anguilla japonica and recruits as far north as southern temperate areas of Japan. A similar pattern is emerging for marine eels that live in coastal or coral reef areas, with evidence that some species of congrid eels in temperate regions make relatively long spawning migrations, but tropical/subtropical species appear to spawn in shallow water or make shorter spawning migrations to the shelf break or deep water, Thus, the latitudinal range and presumably the environmental conditions in the coastal waters surrounding the growth habitats of eel species may be important factors determining the distance of the spawning migrations of eel species, as a result of the unique ecology of their leptocephalus larvae.
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  • MARIE-NOËLLE DE CASAMAJOR, RAYMONDE LECOMTE-FINIGER, PATRICK PROU ...
    2002 Volume 68 Issue sup1 Pages 41-44
    Published: 2002
    Released: June 30, 2008
    JOURNALS FREE ACCESS
    The purpose of this work was to characterize the quality of glass-eel recruitment during season of migration and transition from the marine to the continental environment. Glass eels were sampled, in the south of the Bay of Biscay from November 1999 to March 2000. The individual degree of slimming was measured from the ratio DNA/dry weight and the water content. The larval history was studied by interpretation of the microstructures registered on the otoliths. During the sampling season, glass eels changed in pigmentation and length and weight decreased. Their energy and water budget remained constant but large individual variations inside each groups were observed. A slimming between glass eels captured at sea and in estuary was observed in December only whereas they were not pigmented. Samples of glass eel otoliths collected on different areas and periods presented microstructural differences. The otoliths of glass eels caught at sea in February presented a smaller radius and a transition mark in estuary. Monthly measurements of growth zones of otoliths showed a similar larval history during the transoceanic migration. These results indicate a mixing of flows of the glass eels between the marine and continental environment at the end of sampling season.
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  • MITSUHIRO NAGATA, SEIJI YANAI
    2002 Volume 68 Issue sup1 Pages 45-48
    Published: 2002
    Released: June 30, 2008
    JOURNALS FREE ACCESS
    Visual and electrofishing observations were conducted in the Atsuta and Shakotan rivers of Hokkaido to investigate changes in habitat use and preference for newly emerged masu salmon fry. Fry favored stream margins with shallow slow moving water, aquatic vegetation and large gravel. As fry grew and energetic requirements increased, they moved to new habitats with faster, deeper water, and less cover where food was presumably more abundant. To optimize growth and survival of young stream-rearing masu salmon, it is essential to restore and conserve stream margins with habitats suitable for these valuable fish.
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  • ARIMUNE MUNAKATA, MASAFUMI AMANO, KAZUMASA IKUTA, SHOJI KITAMURA, KATS ...
    2002 Volume 68 Issue sup1 Pages 49-52
    Published: 2002
    Released: June 30, 2008
    JOURNALS FREE ACCESS
    In masu salmon, Oncorhynchus masou, yearling immature fish migrate downstream into the sea after parr-smolt transformation in spring. However, precociously mature yearling males that had high plasma sex steroids levels show neither smolting nor downstream migratory behavior in this period. From spring through autumn, 2-year-old mature adults which returned to their home rivers and yearling precocious males migrate upstream to their spawning ground. In order to know the involvement of sex steroids in the regulation of migration, testosterone (T), estradiol-17β (E2), 11-ketotestosterone (11-KT), or 17, 20β-dihydroxy-4-pregnene-3-one was implanted into immature fish and castrated precocious males, and downstream and upstream migratory behavior, and spawning behavior were observed by use of an artificial raceway and stream channel. Sex steroids such as T, E2, and 11-KT inhibited downstream migratory behavior, and stimulated upstream migratory behavior and spawning behavior. These findings suggest that sex steroids are the factors stimulate mature masu salmon to migrated toward their spawning ground.
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  • HIROSHI UEDA, TAKAYUKI SHOJI
    2002 Volume 68 Issue sup1 Pages 53-56
    Published: 2002
    Released: June 30, 2008
    JOURNALS FREE ACCESS
    There are still many mysteries about the amazing abilities of salmon to migrate long distances from open water to their home streams for spawning. Three different approaches ranging from molecular biology to behavioral biology have been applied to investigate mechanisms of salmon homing migration using chum salmon (Oncorhynchus keta) from the Bering Sea to Hokkaido as well as lacustrine sockeye salmon (O. nerka) and masu salmon (O. masou) in Lake Toya and Shikotsu, Hokkaido, Japan. These fish offer good model systems for studying salmon homing migration. The endocrinological studies revealed that the brain-pituitary-gonadal axis plays leading roles in homing migration. The sensory physiological studies suggested that amino acids dissolved in the natal stream water are possible home stream odorants. The biotelemetrical studies provided new concepts for orientation ability in open water, energetics of migration, and environmental preferences of migrating fish. We are confident that these approaches using our useful model system will provide valuable new information about the physiological mechanisms of homing migration in salmon.
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  • AKIRA GOTO
    2002 Volume 68 Issue sup1 Pages 57-62
    Published: 2002
    Released: June 30, 2008
    JOURNALS FREE ACCESS
    The freshwater fishes in the northern Far East were investigated to elucidate the species richness, ecological complexity and genetic diversity. The fishes in Hokkaido Island, Sakhalin Island, Primoee and the Amur River basin were composed of 27 families, 83 genera and 130 species which possessed high ecological and genetic diversity. Concerning the freshwater sculpins, for example, one Trachidermus, one Mesocottus and 11 Cottus species are distributed in the regions. The mitochondrial DNA analyses made clear that the amphidromous, lacustrine and fluvial species have originated from the ancestral stocks of catadromous species such as T. fasciatus and Cottus kazika, showing the creation of species diversity. Mainly because of rapid changes of freshwater environments, however, nearly 10-40% fish species to the total number of species distributed in the regions were found to be endangered, indicating the necessity of effective conservation actions.
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  • CHUNGUANG ZHANG, TYSON R. ROBERTS, YAHUI ZHAO
    2002 Volume 68 Issue sup1 Pages 63-66
    Published: 2002
    Released: June 30, 2008
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    The numerous distinct inland biogiographic areas and diverse freshwater ecosystems of China are inhabited by over 1000 freshwater fish species. Over 11% of the species are now supposedly either rare or endangered. Many reasons have been identified as contributing to this decline. Some measures have been taken to protect fish species. Conservation of freshwater fish will be more successful if additional measures are considered.
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  • YUJI YAMAZAKI
    2002 Volume 68 Issue sup1 Pages 67-70
    Published: 2002
    Released: June 30, 2008
    JOURNALS FREE ACCESS
    Allozyme analyses were performed to disclose the phylogenetic relationships among Lethenteron species occurring in the Far East. As a result, several complete allele substitutions were found between all sympatric pairs of four Lethenteron taxa, strongly suggesting the existence of reproductive isolation among them. Therefore, these four taxa, L. japonicum, L. kessleri, and the northern and southern forms of L. reissneri, should be regarded as discrete species. Lethenteron japonicum appeared to be closely related to L. kessled and the northern form of L. reissneri, whereas the southern form of L. reissned was greatly divergent from the other three Lethenteron species, suggesting that the former three species are monophyletic. In the monophyletic group, the two nonparasitic (and fluvial) species, L. kessleri and the northern form of L. reissnen, are supposed to have speciated from the ancestral stocks of parasitic (and anadromous) L. japonicum in different geological times. The present study also indicates that some taxonomic problems are comprised in fluvial, nonparasitic lamprey species from the Far East. At present, some fluvial lamprey species and local populations are faced with endangered situation in Japan and Korea.
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  • TOSHIRO SARUWATARI, ICHIRO OOHARA, TAKANORI KOBAYASHI
    2002 Volume 68 Issue sup1 Pages 71-74
    Published: 2002
    Released: June 30, 2008
    JOURNALS FREE ACCESS
    A review on the biology of Far East Teleost family Salangidae is presented, based on recent studies conducted by the authors during the past decade.
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  • YUKIMASA ITO, HARUMI SAKAI, SERGEI SHEDKO, SANG RIN JEON
    2002 Volume 68 Issue sup1 Pages 75-78
    Published: 2002
    Released: June 30, 2008
    JOURNALS FREE ACCESS
    Although minnows of the genera Phoxinus and Rhynchocypris (Cyprinidae) are abundantly distributed in the northern Far East region, disagreements on their taxonomy have persisted. Gene products of 18 allozyme or protein coding loci of 21 populations of minnows from the northern Far East were investigated in order to resolve their classification and genetic relationships. Six monophyletic dusters were identified, being consistent with Phoxinus phoxinus, Rhynchocypris oxycephalus, R. percnurus, R. czekanowskii, R. kumgangensis and R. semotilus, plus one paraphyletic group referred to as R. lagowskii.
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  • HANNES H. GISSURARSON
    2002 Volume 68 Issue sup1 Pages 79-84
    Published: 2002
    Released: June 30, 2008
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    Many fish stocks are fugitive resources, migrating in and out of territorial waters. A system of individual transferable quotas, ITQs, may make their efficient management possible. Iceland is an example. She has negotiated, with her neighbouring countries, a share in the total allowable catch of several fish stocks in the North Atlantic Ocean. Then government has allocated this share as ITQs to fishing firms, on the basis of catch history. This makes owners of fishing vessels responsible partners in fisheries management, with a vested interest in the future of the stocks.
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  • TOKIO WADA
    2002 Volume 68 Issue sup1 Pages 85-88
    Published: 2002
    Released: June 30, 2008
    JOURNALS FREE ACCESS
    Recently about one half of the stocks in Japanese exclusive economic zone (EEZ) have been declined or are stable at low abundance levels. With the ratification of the United Nations Convention on the Law of the Sea, Japan newly introduced a management system based on total allowable catches (TACs). However, the TACs are sometime set quite larger than the scientifically estimated biological allowable catches (ABCs). The existence of several management bodies for a single stock is one reason that TACs are often set larger than ABCs.
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  • YOUNG CHEOL PARK, MARI YODA, YOSHIAKI HIYAMA
    2002 Volume 68 Issue sup1 Pages 89-92
    Published: 2002
    Released: June 30, 2008
    JOURNALS FREE ACCESS
    The present study investigates the status of swordtip squid (Loligo edulis) stocks in the southwest sea of Japan and the East China Sea, which are multi-gear and multi-national fishing grounds. Commercial landings of six fisheries for the period 1980-99 and eight research trawl-survey data sets from 1986 from 1999 were used to estimate minimum biomass in each fishing ground. The relationships between stock and recruitment and between catch and fishing effort were estimated using regression analysis. The maximum sustainable yield (MSY) and the corresponding fishing effort for given interspecies relationships are then obtained. Predicted fishing effort rates were estimated from a relative gross profitability for each fishery for the past 5 years and were proposed as an alternative standard to assign the fishing effort to each fishery. Estimates of fishing effort at MSY were above the current fishing effort in the southwest sea of Japan and the East China Sea. However restraint for the increase rate in fishing effort is required in the East China Sea to prevent stock collapse. The present results also suggest that fishing effort for the Chinese offshore trawl fishery should firstly be reduced, if the fishing effort has to be adjusted in the East China Sea.
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  • an example of allowable biological catch determination
    AKIHIKO YATSU, TAKUMI MITANI, CHIKAKO WATANABE, HIROSHI NISHIDA, ATSUS ...
    2002 Volume 68 Issue sup1 Pages 93-96
    Published: 2002
    Released: June 30, 2008
    JOURNALS FREE ACCESS
    Stock biomass of the Pacific stock of Scomber japonicus decreased from ca. 4-6 million tons during the early and mid 1970's to less than one million tons in the 1990's. This decline was probably caused from over-fishing and decreased reproductive success corresponding to regime shifts in the late 1970's and 1980's. We decided to keep the spawning stock biomass (SSB) above 0.45 million tons, because 1) no recruitment failures were observed above this level and 2) this SSB can be attained by preserving dominant year classes until their maturation (age-3). Problems of the allowable biological catch determination method in Japan were discussed and a practical solution was presented.
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  • CHIKAKO WATANABE, HIROSHI NISHIDA
    2002 Volume 68 Issue sup1 Pages 97-100
    Published: 2002
    Released: June 30, 2008
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    Biomass estimates of pelagic fishes from both fishery-dependent and independent data are necessary for robust stock assessment and fishery management. The spawning biomass of the chub mackerel Scomber japonicus was estimated for 1996 and 1998 by the daily egg production method (DEPM), though the estimates were smaller than those of the virtual population analysis (VPA) in 1998 when the sampling spatially and temporally mismatched to the actual spawning. Abundance indices of young-of-the-year (YOY) of chub mackerel and Japanese sardine Sardinops melanostictus (30-170mm BL) were obtained by a pelagic trawl survey using a net with a 27m×27m mouth opening in the Kuroshio-Oyashio transition region (36-40°N, 143-170°E) during 1996-2001. The indices fairly agreed with the recruitment levels estimated by VPA, and hence could be used for recruitment forecasts.
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  • TOSHIHIRO WATANABE
    2002 Volume 68 Issue sup1 Pages 101-104
    Published: 2002
    Released: June 30, 2008
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    The sock abundance of the snow crab Chionoecetes opilio has been estimated based on trawl and pot surveys in Japan. However, the gear efficiency has not been sufficiently measured. As a direct observation method to estimate the population density of the snow crab, the Deep-sea Video Monitoring System on a Towed Sledge (DVMSTS) was developed and its effectiveness was demonstrated in field observations. To improve the accuracy of the crab population density estimated from the amount of crab catches obtained by the survey pot, the Effective Fishing Area Per Survey Pot (EFAPSP) was estimated using the DVMSTS. The observations by DVMSTS and pots fishing operations were performed 18 times in total off the Oki Islands in the Sea of Japan in April to May, 2000. The EFAPSP was estimated to be approximately 1, 600m2/pot. The DVMSTS can be utilized for not only estimation of the population density but also calibration of the gear efficiency for the snow crab.
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  • TOSHIHIDE KITAKADO
    2002 Volume 68 Issue sup1 Pages 105-108
    Published: 2002
    Released: June 30, 2008
    JOURNALS FREE ACCESS
    The maximum likelihood method has become a commonly used technique in fish population analysis. Also, information criteria based on the maximum likelihood method have often been used for model selection. On the other hand, drawbacks of the maximum likelihood estimator (MLE) have been found in some situations. For example, the MLE may be inconsistent in models with many nuisance parameters. Also, the MLE may not be robust with respect to the misspecifi action of probability distribution. To overcome these difficulties, several likelihood approaches such as conditional likelihood, integrated likelihood, and quasi-likelihood have been developed. These approaches can be applied to improve the performance of estimation in fish population analysis. This paper illustrates characteristics of these approaches and gives their possible applications such as estimation of growth parameters.
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  • TOM NISHIDA, GEOFF J. MEADEN, ANTONY J. BOOTH
    2002 Volume 68 Issue sup1 Pages 109-112
    Published: 2002
    Released: June 30, 2008
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    This paper reviews the current situation vis-à-vis GIS in spatial marine fish resources analyses. It is based upon some 200 selected papers presented in four symposia in 1999, i.e., “First International Symposium on GIS in Fishery Science”, “Ecosystem Effects of Fishing”, “GIS Applications for Agro-Environmental Issues in Developing Regions” and “Spatial Process and Management of Fish Population. The selected papers are summarized under following four categories: (a) basic presentation (mapping) of parameters, (b) fisheries oceanography and marine ecosystems research, (c) geo-referenced fish resource assessments and analyses, and (d) space-based management and predictions. Based on the current situation, we further discuss prospects and future applications for spatial fish resources analyses using GIS.
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  • PETER F. SALE
    2002 Volume 68 Issue sup1 Pages 113-118
    Published: 2002
    Released: June 30, 2008
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    In the last 10 years, new techniques have helped answer some of the most difficult questions in reef fish ecology, and a broader range of topics has been investigated. Despite this there has been an increasing emphasis on studies of larval biology, recruitment dynamics, and early postsettlement demography. This focus exists because these topics are key to understanding demography of reef fish populations, and because improved management depends on understanding demography, and particularly the connectivity due to larval exchange between populations. I review these advances, and make suggestions for the future. I outline ECONAR, a regional-scale, multi-disciplinary project, as the kind of program needed to gain satisfactory answers to major questions in reef fish ecology.
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  • KIROSHI KAWASE
    2002 Volume 68 Issue sup1 Pages 119-122
    Published: 2002
    Released: June 30, 2008
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    Reproductive ecology of 14 balistdd species (Balistidae and Monacanthidae) was reviewed. There are many common features in the reproductive ecology of the balistid fish: males establish territories; males and females mate in pairs on the sandy bottom; the pairs release gametes in a few seconds; eggs are small in size and a clutch contains large number of eggs; spawning occurs in the morning and embryos hatch after sunset of the day; females tend and guard the eggs at least Primitive monacanthid species show the same features of the balistids, however, reproductive ecology of the monacanthids is diverse. The evolution of reproductive ecology of the balistoids was discussed referring to the phylogenelic relationships.
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  • TAKESHI KANDA, SHUHEI KAMURA, MIKIKO NAKATSUKI, NORIE OKADA
    2002 Volume 68 Issue sup1 Pages 123-126
    Published: 2002
    Released: June 30, 2008
    JOURNALS FREE ACCESS
    Males of the goby occupy the nests with a small entrance and brood periodically in semilunar cycles. We investigated the preference of males to the shape of nests using the brooding periodicity and experimental nests with various sizes of body and various sizes of entrance. Brooding in semi-lunar cycle and sharper hatching peaks indicate that the timing of releasing of larvae must be precise for their reproduction. Males appear to select the nests by means of not nest size, but entrance size, even though large nests have a larger capacity of eggs than small ones. The analyses using the selection order index, SOI, showed the same results. Our observations show that one of the reasons why they need the nest with small entrance should be intrusion of sneakers.
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  • AKINOBU NAKAZONO
    2002 Volume 68 Issue sup1 Pages 127-130
    Published: 2002
    Released: June 30, 2008
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    Every year, various species of juvenile reef fishes from tropical and warm temperate populations are carried by currents to the temperate northern coast of Kyushu, southwestern Japan. There, they settle on to rocky reefs but usually fail to survive cold sea temperatures brought on by winter. The purpose of this study was to determine the species composition of tropical and warm temperate fishes that settled annually at Tsuyazaki, Fukuoka Prefecture (33° 47'N, 130° 29'E) and to determine their pattern of occurrence in 19 of 37 years between 1964-2000. The total number of species recorded ranged between 7-19 species annually. Among these, seven species were recorded each year while 1-12 species occurred sporadically. The largest number of species, 12, was recorded in the year 2000. One species, Parapercis snyderi (Pinguipedidae), that first appeared in 1988, has been able to survive winter sea temperature and reproduce successfully. Three other species that occur regularly survived winter of 1999-2000, as well. The pattern of settlement of these fishes at Tsuyazaki appear to related to a rise in sea water temperature in recent years.
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  • MICHAEL KINGSFORD
    2002 Volume 68 Issue sup1 Pages 131-134
    Published: 2002
    Released: June 30, 2008
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    Girellids and sparids rank highest as the groups of fishes taken by rock fishers in New South Wales, Australia. Rapid visual counts that were stratified by depth and transects that were stratified by habitat (e. g. kelp forest and urchin grazed barrens) showed that girellids were most abundant in shallow water (<3m deep). A few aggregations (primarily Girella tricuspidata) were found in waters up to 15m deep. No juvenile G. tricuspidata were observed on reefs, all of the fish in counts were greater than 200mm SL. In contrast, G. elevata of all size lasses (30-300mm SL) were found in water less than 3m deep. Almost all Kyphosus (98%) were in shallow water. Sparids (57%) were found in shallow water, although some (Pagers auratus) were only found in deep or mid-depth strata. Girellids, kyphosids and some sparids used the intertidal at high fide. Girellids were observed to feed in the shallows. Juvenile G. elevata (30-70mm SL) fed in the intertidal mostly on rocky surfaces, tubeworrns and the backs of large limpets (Cellana spp.) where algae were abundant. Shallow waters and the intertidal of rocky reefs have probably been underestimated in terms of importance to fisheries.
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  • YVONNE SADOVY
    2002 Volume 68 Issue sup1 Pages 135-138
    Published: 2002
    Released: June 30, 2008
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    Reef fisheries are of considerable socioeconomic importance globally. Per ton of fish caught, they are more efficient and provide more livelihoods than industrial-scale fisheries while involving less wastage of food resources and use of fuel. Currently, however, their worth is not fully recognized and they are rarely monitored or managed to ensure long-term persistence. Moreover, a number of commercially important reef fish species may be particularly vulnerable to fishing pressure because of their life history characteristics. These include, long-life and late sexual maturation as well as complexities of social and mating systems that have arisen as a result of a long and close evolutionary association with the reef habitat. Such characteristics also mean that they are disrupted readily by fishing and negatively affected by loss of habitat.
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  • TAKURO SHIBUNO, KAZUMASA HASHIMOTO, OSAMU ABE, YOSHITAKE TAKADA, HIROY ...
    2002 Volume 68 Issue sup1 Pages 139-142
    Published: 2002
    Released: June 30, 2008
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    We have monitored the fish fauna and coral cover at permanent transects on a reef flat, an offshore moat near a reef flat, and a moat near shore at Urasoko Bay, Ishigaki IsI., Japan. In August 1998, we observed severe coral bleaching on the reef. We compared the fish fauna before and two years after this coral bleaching episode to examine the effects of the coral bleaching on fish community structure, and particularly upon fishes of the family Pomacentridae. The benthic substrata on the reef flat and offshore moat consisted mostly of living Acropora spp. before the summer of 1998, however, most of the living coral had died after the coral bleaching. In contrast, the benthic substrata at the near shore moat consisted mostly of dead coral rubble and sand, with several microatolls of massive Porites sp corals. This living coral was not affected by the bleaching episode. On the reef flat, herbivore pomacentrids, Stegastes fasciolatus and Pomacentrus bankanensis, were abundant until two years after the coral bleaching. In the offshore moat, however, the planktivorous pomacentrid Pomacentrus moluccensis, whose abundance decreased on the reef flat after the coral bleaching, was abundant after the coral bleaching. This change was probably dependent upon the remaining of structural complexity of the remaining coral branches in the offshore moat during the two years after the coral bleaching. In the near shore moat, omnivorous Pomacentrus sp. (Japanese name: Minami-isosuzumedai) was abundant in the surveys before and after the coral bleaching.
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  • TERRY J. DONALDSON
    2002 Volume 68 Issue sup1 Pages 143-147
    Published: 2002
    Released: June 30, 2008
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    Coral reefs and associated systems support highly diverse assemblages of fishes that demonstrate remarkable variation in patterns of geographic distribution, ecology, behavior and life history. Unfortunately, our understanding of these patterns is relatively limited. Meanwhile, many species for which little information exists are under direct or indirect threat from destructive fishing, over-fishing, and habitat loss associated with fish harvests and from the effects of coral bleaching. The necessity to obtain good data is in conflict with the urgency to define species-specific levels of sustainability, if any, and to develop and implement effective conservation and management plans. Phylogenetic methods may be utilized to analyze life history traits, and well as patterns of ecology and behavior. These methods have been applied in intra- and intergeneric comparisons or in comparisons between different families of fishes. The results have predictive value for related species for which little or no data exist. This point is illustrated in comparisons within two families of reef fishes, the groupers (Serranidae: Epinephelinae), which are harvested for food, and the hawkfishes (Cirrhitidae), which are harvested largely for the aquarium trade.
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  • TSUYOSHI KAWASAKI
    2002 Volume 68 Issue sup1 Pages 148-153
    Published: 2002
    Released: June 30, 2008
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    As more and more data of long-term variability in marine organisms from phytoplankton to predatory fish accumulate, a persistent pattern of the interdecadal and global scale, regime shift, is emerging. Many of the fish populations are growing and declining rhythmically with a high degree of synchrony. A skyrocketing improvement in chum salmon's rate of return to Japan as brought about by a technological innovation is now unacceptable and it seems to embody the regime shift. Abundant evidence in support of the regime shift has been given recently for the variability in climate-ocean system which suggests that climate change may be the driving force linking the variations in marine populations. There are some forerunning studies that lead to mechanisms causing global concurrence in ocean enrichment. In the traditional population dynamics that has underlain the current stock management regime and enhancement programs, it is assumed that a fish population is in equilibrium with the fishing effort under average environmental conditions. Change in biomass due to environmental variations is regarded as a noise and hence an unfished population remains unchanged. The theory, however, has turned out inconsistent with the real world and it needs be examined.
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  • A case study using Ecopath and Ecosim
    HIROSHI OKAMURA, AKIHIKO YATSU, KAZUHIKO HIRAMATSU
    2002 Volume 68 Issue sup1 Pages 154-157
    Published: 2002
    Released: June 30, 2008
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    The Ecopath model for the western North Pacific was constructed and some preliminary analyses were carried out in order to examine the usefulness of the model for multi-species management. Our Ecopath model consisted of 30 species groups based on the information that is mainly collected from published literature, Some Ecosim simulations showed non-trivial interaction between cetaceans and fishes and relative biomass of some cetaceans and fishes changed dramatically when their present harvest rates were changed in future. Fitting our model to the available abundance indices of some fishes indicated that the vulnerability parameter in the model was likely to be high. Further, additional simple simulation suggested that we could achieve targeted biomass of mackerel by adjusting the future harvest rate of cetaceans in place of that of mackerel. This indicates that multi-species management in the western North Pacific area might bring efficient fishing strategy. However, the results were very sensitive to setting of the vulnerability parameter. Therefore, Ecopath and Ecosim should not be considered as tools for multi-species management until uncertainty of important parameters is properly incorporated into Ecopath/Ecosim and the difference between them and a single-species model becomes clear. Nevertheless, those results from ecosystem models such as Ecopath and Ecosim are suggestive and valuable when they are brought up along with the result of single-species assessment.
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  • YONGJUN TIAN, YASUHIRO UENO, MAKI SUDA, TATSURO AKAMINE
    2002 Volume 68 Issue sup1 Pages 158-161
    Published: 2002
    Released: June 30, 2008
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    Effects of oceanic-climate changes on the abundance of Pacific saury (Cololabis saira) in the northwestern Pacific during the last half century were investigated. The abundance of both large and medium size groups of saury exhibits decadal-scale variation pattern, suggesting strong effects of decadal-scale changes or regime shifts in the oceanic environment. The abundance index of large size group saury is significantly correlated with the winter sea surface temperature (SST) in the Kuroshio region, the main spawning grounds in winter. The spatial and temporal response of large size group saury to SSTs demonstrated that winter SSTs in the Kuroshio region have marked impacts on the year-class success of the winter-spawning cohorts. The large size group saury also showed significant correlations with the Southern Oscillation Index (SOI) and Asian Monsoon Index (MOI), indicating effects of the El Nino Southern Oscillation (ENSO) and winter Asian Monsoon. Linkages between SST and SOI, and between SST and MOI demonstrated that the abundance of large size group saury were directly affected by the SST fields of the spawning grounds in the Kuroshio region in winter through large-scale atmosphere-ocean interactions such as ENSO events and the winter Asian monsoon.
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  • TOSHIO KATSUKAWA
    2002 Volume 68 Issue sup1 Pages 162-165
    Published: 2002
    Released: June 30, 2008
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    Populations of many small pelagic fishes are known to fluctuate drastically. Small pelagic fishes off the coast of Japan boom in cycles, a phenomenon known as species replacement. The population of chub mackerel (Scomber japonicus) increased in the 1960s and decreased in the late 1970 s. The population of Japanese sardine (Sardinops melanostistus) increased in the 1980 s, and recently. Anchovy (Engraulis japonicus) has become abundant. The traditional idea of MSY relies on the assumption that stocks will settle into equilibrium if fishing pressure remains constant. The abundance of pelagic fishes, such as sardine or mackerel, changes drastically even under constant fishing pressure. Because of their variability, management of pelagic fishes with species replacement is difficult. In this paper, I investigated the effects of target switching among stocks that experience species replacement. This study revealed that target switching was effective for stocks with replacement, especially when the recruitment fluctuation was large. In some cases, the yield increased by 261% following target switching. Well-designed target switching is useful for multispecies management for non-equilibrium bioresorces.
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  • HIROAKI ISHII, TAKERU KITAHARA
    2002 Volume 68 Issue sup1 Pages 166-169
    Published: 2002
    Released: June 30, 2008
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    In the present study, we studied a small trawinet fishery in Tokyo Bay which mainly targeted mantis shrimp (Oratosquilla oratona) and discarded many small mantis shrimp. We surveyed the numbers and body length of discarded and landed mantis shrimp aboard a small trawlnet boat once a month from January 1993 to December 2000. Body length (BL) of the mantis shrimp caught by this boat ranged from 8 to 13cm, and those less than 10cm in BL were discarded because they are commercially unmarketable. The number of discarded mantis shrimp markedly increased in summer, reaching a high of more than a million per month. The high numbers of discarded small mantis shrimp in summer are due to 2 main factors: 1) fishermen often use nets with small mesh sizes, in order to catch other species; 2) around May, they begin catching small mantis shrimp that were spawned the year before and are still commercially unmarketable.
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  • TAKASHIGE SUGIMOTO
    2002 Volume 68 Issue sup1 Pages 170-171
    Published: 2002
    Released: June 30, 2008
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    Effects of climate regime shift, ENSO activities and winter monsoon on western boundary currents and upper ocean stratification, as well as their combined effects on plankton biomass and Japanese sardine population are described through analyses of historical time series data. The results are: 1) bidecadal scale variation in the atmospheric condition, coupled with the intensity of winter monsoon influences upper mixed layer depth and density stratification of the ocean, and the volume transport and the current path of the Kuroshio and Oyashio; 2) in the western subtropical North Pacific, weakening of winter cooling and vertical mixing associated with calm and warm winter during the early 1970s, increased surface chlorophyll concentrations in winter in the coastal and offshore water of the Kuroshio, which caused active spawning of mesozooplankton and better feeding condition for sardine larvae; 3) a remarkable weakening of southward intrusion of the Oyashio off the east of Japan during 1988-91 decreased plankton biomass in the Kuroshi-Oyashio transition region in late spring-early summer, and might have caused successive recruitment failures, inducing collapse of Japanese sardine population.
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  • DONALD E. HOSS, JOHN S. BURKE
    2002 Volume 68 Issue sup1 Pages 172-177
    Published: 2002
    Released: June 30, 2008
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    The survival rate during the early life stages of a species is considered critical in determining a year class's contribution to a fish stock. Early life stages have often been considered passive particles and the patterns of distribution in nature the result of differential mortality due to biotic factors (food availability, predation, competition) and environmental variability (temperature, water quality and movement). Though important, this view fails to account for the different patterns of larval behavior that influence the distribution of juveniles. Examples are given to illustrate how transport and retention mechanisms are accomplished through vertically oriented behaviors.
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  • DAVID H. SECOR
    2002 Volume 68 Issue sup1 Pages 178-181
    Published: 2002
    Released: June 30, 2008
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    The Asian temperate sea bass, Lateolabrax japonicus has strong taxonomic affinities with the North American Morone saxatilis and European Morone labrax, despite wide geographic separation. L. japonicus and M. labrax populations exhibit varying levels of estuarine dependency (facultative amphidromy), while M. saxatilis shows varying levels of coastal dependency (facultative anadromy). Based upon phylogenetic evidence, it is hypothesized that anadromy in M. saxatilis evolved from a marine-spawning ancestor, contrary to the prevailing view for salmonids: that anadromy evolved from freshwater ancestors. Higher stability of east coast North American estuaries in comparison to European and Asian estuaries may explain the unique pattern of anadromy and freshwater radiation in North American temperate basses.
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  • SHARON Z. HERZKA, G. JOAN HOLT, SCOTT. A. HOLT
    2002 Volume 68 Issue sup1 Pages 182-185
    Published: 2002
    Released: June 30, 2008
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    In previous work, we showed the _??_13C and _??_15N of red drum (Sciaenops ocellatus) larvae changed following recruitment from planktonic, coastal habitat to seagrass meadows in an estuary. Stable isotope ratio (SIR) measurements therefore served as endogenous tracers of estuarine recruitment. We developed and validated an empirical model based on SIR to back-calculate the time between recruitment and capture for individual larvae (Trec) and the standard length at which estuarine immigration occurred (Lfec) for an entire recruitment season. Trec estimates were used to reconstruct the daily pattern of estuarine recruitment. Lrec values were used to identify the size-class specific abundance of larvae that immigrated successfully to the estuary. We propose that SIR's may be used to study recruitment to a variety of marine systems. We outline the groundwork necessary for using the empirical model. Lastly, published growth rates are used to estimate the window of opportunity in which recent recruits can be identified based on their SIR and within which the model can be applied.
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  • RAFAEL PÉREZ-DOMÍNGUEZ, JOAN G. HOLT
    2002 Volume 68 Issue sup1 Pages 186-189
    Published: 2002
    Released: June 30, 2008
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    Red drum early larval stages migrate through coastal inlets and settle into shallow seagrass meadows within estuaries. This study describes environmental rhythms (ER) in red drum nursery habitats and evaluates their role in larval growth. Well-defined dial ER were observed in temperature (amplitude: 2 to 4.5°C) and dissolved oxygen (DO) (range: 2.9-7.5mg O2 L-1), and sporadic cooling caused by cold fronts. We exposed groups of settlement sized larvae (4.9mm standard length) to two oscillating temperature treatments (amplitudes: 3 and 6°C; daily mean 27°C), an oscillating DO treatment (range: 2.4-6.1mg O2 L-1; daily mean 4.2mg O2 L-1 ) and a control (no cycles; daily mean 27°C, 6.4mg O2 L-1). Relative to controls, growth was significantly reduced in the DO treatment but not in the temperature treatments. Survival was similar in all treatments. Fish previously exposed to temperature cycles maintained faster growth rates and higher food intake than control fish when exposed to a simulated cold front. These results suggest that (1) ER may impart a physiological advantage to fish, (2) acclimation to oscillating DO environments is unlikely, and (3) field estimates of environmental characteristics based upon averaged daily point samples are inadequate for predicting fish growth.
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  • GUIDO PLAZA, S. KATAYAMA, M. OMORI
    2002 Volume 68 Issue sup1 Pages 190-193
    Published: 2002
    Released: June 30, 2008
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    In this study otolith microstructure was used to reveal the early life history events of the black rockfish S. inermis immigrating into a temperate seagrass bed northern Japan in 1998 and 1999. Otolith had a prominent check, which was linked to settlement. Extrusion dates were distributed from late December to early March. Planktonic period showed a wide range from 55 to 110 days in 1998, and from 65 to 113 days in 1999, suggesting the delay in metamorphosis. Settlement dates extended from late March to late May and synchronized closely to both the first-third quarter moon cycle (neap tides) and the new-full moon cycle (spring tides) in 1998 and 1999, respectively. Back-calculated size at settlement did not vary significantly among settlement groups, which suggests the existence of a competent size to settle. Recent growth rates were high after settlement and regressed directly with shoot weight and height of Zostera marina, and inversely with water temperature.
    We discussed the “tidal control” and “settlement linkage” hypotheses concerning temporal settlement patterns as well as growth traits of S. inermis in relation to the utilization of Z. marina beds as a nursery ground.
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  • TAKU YOSHIMURA, KENJI MORINAGA, SHIGERU SHIRAI, HIROSHI YAMAKAWA
    2002 Volume 68 Issue sup1 Pages 194-197
    Published: 2002
    Released: June 30, 2008
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    Widespread ichthyopianidon samplings were conducted along the Pacific coast of Japan in winter 1989 to 1992 to monitor abundance of larval Pacific saury. Middle- and late stage phyllosoma larvae of the Palinur dae were found among the surface net samples. All of these larvae were caught at night, and they were distributed widely south of the Kuroshio. They were identified as Form A, and were likely to be the larvae of the Japanese spiny lobster, Panulinis japonius, or of the ‘P. longpes complex’ on the basis of their morphological characteristics and the known adult distribution area.
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  • TSUNEO GOTO, HIDEAKI KIDOKORO, SHOGO KASAHARA
    2002 Volume 68 Issue sup1 Pages 198-201
    Published: 2002
    Released: June 30, 2008
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    Larval distribution is one of the most basic topics of the study on early life history. In order to determine the paralarval distribution and abundance of the ommastrephid squid Todarodes pacificus, annual surveys during October-November have been conducted from the southwest Sea of Japan to the northern part of the East China Sea since 1973. Paralarvae were collected by 80cm diameter ring nets towed obliquely from a depth of 75m to the surface. The results indicate that the paralarvae were abundantly distributed all over the survey area when stock levels were high in the early 1970 s and after the late 1980 s, and that when stock levels were low, the range of paralarval distribution contracted northeasterly. We conclude that these changes of paralarval distribution may be a direct cause of stock fluctuation.
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  • KEVIN M. BAILEY
    2002 Volume 68 Issue sup1 Pages 202-205
    Published: 2002
    Released: June 30, 2008
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    The processes that establish the survival of walleye pollock larvae are complex. High frequency events during egg and larval life introduce noise to the dynamics of the population. Forecasts of recruitment must account for this complexity. Initial conditions impacting larval survival do not significantly account for variability in recruitment, but information on abundance near the prediction target are fairly accurate in forecasting year-class strength, following expectations from complexity theory.
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  • AKIRA NISHIMURA, TOMONORI HAMATSU, KEIZO YABUKI, OSAMU SHIDA
    2002 Volume 68 Issue sup1 Pages 206-209
    Published: 2002
    Released: June 30, 2008
    JOURNALS FREE ACCESS
    We review published/unpublished information on the early life stage of walleye pollock along the Pacific coast of Hokkaido. Evidence of the recruitment fluctuations was suggested by cohort analysis, and the 1995 year class was recognized as the strongest year class in the last two decades. The highest distribution of eggs was observed in the vicinity of Funka Bay, the southwestern part of Hokkaido. Egg transport and match/mismatch processes are pointed out as possible causes of recruitment fluctuations during the larval stages. In August 2000, we observed a high-density juvenile aggregation in the eastern Pacific Hokkaido. The estimated hatch dates of juveniles ranged between early-January and mid-March, suggesting they originated from Funka Bay. We suggest that the juveniles migrate from Funka Bay to the eastern Pacific Hokkaido during their first summer and that they use this area as for a nursery ground. Larval transport, migration mechanism and environmental conditions in the nursery area may also be important in establishing year-dass strength.
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  • HITOSHI HONDA, MINORU ISHIDA, TAKUMI MITANI, SHINJI UEHARA, YUICHI HIR ...
    2002 Volume 68 Issue sup1 Pages 210-213
    Published: 2002
    Released: June 30, 2008
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    We evaluated the age structure and the maturity condition of the Japanese sardine spawning in Tosa Bay during the period of small stock size to confirm the year class strength and to maintain the spawning stock. Samples were collected in Tosa Bay, southwestern Japan, which is one of the main spawning grounds of the Japanese sardine in the Pacific coast of Japan, in the spawning seasons of 1999-2000 and 2000-2001. The year class composition and the gonad maturity of the spawning stock were analyzed. The spawners in Tosa Bay were composed of the 1998-year-class in 1999-2000 and of the 1998 and 2000-year-classes in 2000-2001. The estimated age at first maturity of spawners in Tosa Bay was about 1-year-old.
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  • EDWARDA TRIPPEL
    2002 Volume 68 Issue sup1 Pages 214-217
    Published: 2002
    Released: June 30, 2008
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    Fish recruitment models are being improved through our increased understanding of maternal and paternal trits that influence embryonic and iarval fitness. New knowledge of the reproductive and developmental biology of Atlantic cod (Gadus morhua), a species exploited for centuries, has fueled further paradigm shifts in stock-recruitment theory that foster an ever increasing conservation perspective. Quantifying parental characteristics that affect future cohort strength requires refined data treatment that integrates annual variation in adult body metrics and demography that in turn influence egg and sperm quality and larval survivorship. Long-term research and stock assessment programs are recommended. These programs will lead to predictions of retrospective and future recruitment levels that are based to a greater degree on reproductive biology.
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  • JUN SHOJI, TSUTOMU MAEHARA, MASARU TANAKA
    2002 Volume 68 Issue sup1 Pages 218-221
    Published: 2002
    Released: June 30, 2008
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    The hypothesis that prey abundance and larval growth rate are related to recruitment was tested in Japanese Spanish mackerel in the central Seto Inland Sea, Japan. The relationships among larval abundance, growth rate, prey fish (clupeiform larvae) abundance, and the catch per unit fishing effort (CPUE) of the subsequent 1-year-old fish were examined from 1995 to 1999. A significant, positive correlation was found between the larval growth rate and the CPUE, but not between the larval abundance and the CPUE. There also existed a significant positive correlation between the abundance of clupeiform larvae and the larval growth rate, which varied from 0.4 to 1.0mm/day. Both the larval growth rate and the CPUE were higher in 1995 and 1999, when the period of peak occurrence of clupeiform larvae timed well with that of the mackerel larvae. It has been concluded that the prey abundance during the early larval period is one of the most important determinants of the growth and recruitment of Japanese Spanish mackerel.
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  • MOTOMITSU TAKAHASHI, YOSHIRO WATANABE
    2002 Volume 68 Issue sup1 Pages 222-225
    Published: 2002
    Released: June 30, 2008
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    Recruitment probability in fishes may be influenced by the growth rate through the larval and early juvenile stages. We collected Japanese anchovy, Engraulis japonicus, by subsurface trawl hauls in the Kuroshio-Oyashio transition region and compared the otolith daily increment widths corresponding to the larval stage between early juveniles (original cohort) and adult survivors. The otolith daily increment widths were wider in the early juveniles with faster larval growth rate than in those with slower growth rate. Otolith daily increment widths tended to be wider in the adult survivors than in the original cohort after age 40d. This result indicated that faster-growing larvae had higher probabilities of recruitment success and resulted in constituting a large proportion of adult population in the Japanese anchovy.
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