Showing papers on "Fishing published in 1986"

Fish Behaviour and Fishing Gear

Abstract: Throughout history, human hunters for fish have made use of their knowledge of fish behaviour in order to make catches. There are more than 22000 different species of teleost fishes, each with its own characteristic world of reaction and behaviour, so that numerous appropriate fish capture systems have been invented. Outlines of our knowledge of the sensory ability and behaviour of fishes have been summarised in the earlier chapters of this book. Fish behaviour is involved in catching fish, both on the oceanic scale, where the annual cycles of maturity cause migrations so that fish are found in different locations that become known to the fisherman by observation of their availability, and on a smaller scale, where the reactions of a fish to each part of an approaching trawl can cause the fish to swim into the codend. In order to be successful, the fisherman must have local knowledge of the day-to-day movements of the fish and of their likely distribution. In all fisheries, one of the most important of the fisherman’s skills is to use the appropriate gear at the right time in the right place.

Fish Faunal Structure in an Ozark Stream: Stability, Persistence and a Catastrophic Flood

Abstract: . 1979. Niche partitioning by food size in fish communities, p. 311-322. In: Predator-prey systems in fisheries management. H. E. Clepper (ed.). Sport Fishing Institute, Washington, D.C. , AND J. F. GILLIAM. 1984. The ontogenetic niche and species interactions in size structured populations. Ann. Rev. Ecol. Syst. 15:393-425. , AND D. J. HALL. 1976. Niche shifts in sunfishes: experimental evidence and significance. Science 191:404-406.

The Fisherman's Problem: Ecology and Law in the California Fisheries, 1850-1980

Abstract: List of figures List of tables Preface Acknowledgments List of abbreviations Introduction 1. The problem of environment Part I. The Miner's Canary: 2. Aboriginal fishery management 3. The Indian fisheries commercialized Part II. Sun, Wind, and Sail, 1850-1910: 4. Immigrant fisheries 5. State power and the right to fish Part III. The Industrial Frontier, 1910-1950: 6. Mechanized fishing 7. The bureaucrat's problem Part IV. Enclosure of the Ocean, 1950-1980: 8. Gridlock 9. Something of a vacuum 10. Leaving fish in the ocean 11. An ecological community Conclusion Appendix Notes Selected Bibliography Index.

An Examination of Fishing Location Choice in the Pink Shrimp Fishery

Abstract: This article analyzes fishing location choices made by pink shrimp (Pandalus jordani) fishermen fishing off the coast of northern California. Data were gathered for 17 commercial vessels making 3000 net sets over a season. A simple multiplechoice logit model was used to examine whether recent information on success in various regions aids in explaining location choice. Results suggest that fishermen do account for economic factors in a manner consistent with economic theories of choice.

A framework for understanding the consumptive orientation of recreational fishermen

Abstract: Fishermen were aggregated into high-, mid-, and low-consumptive groups according to the importance they placed on catching fish. Analysis of variance indicated that each consumptive group was unique in the importance it placed on other fish-related variables. Low-consumptive fishermen rated most other aspects of the fishing experience, such as interacting with nature, relaxation, and escaping the daily routine, more important than did high-consumptive fishermen. Low-consumptive fishermen also fished more frequently and were generally more satisfied with their most recent fishing trip than were high-consumptive-oriented fishermen. The three groups can be viewed as different fishing constituencies. By understanding their characteristics, we can gain additional insights into the impacts of management decisions on recreational fishermen and their experiences.

Situational and subjective determinants of satisfaction in marine recreational fishing.

Abstract: This paper examines the influence of tangible trip outcomes and subjective evaluations on overall trip satisfaction in marine recreational fishing. The paper proposes a model of fishing satisfaction that integrates subjective and situational factors as well as consumptive and nonconsumptive elements of the experience. A replicated analysis of separate samples of Delaware and Maryland fishermen was used. Findings demonstrate that a significant portion of the variance in satisfaction could be explained by a set of identifiable components of the total experience. Overall satisfaction was influenced most strongly and most directly by subjective evaluations of specific aspects of the experience. Situational outcomes influenced overall satisfaction in a more indirect manner as they were filtered through various subjective evaluations. The proposed fishing model suggests that consumptive outcomes are more important than they appear from the typically weak correlations found between satisfaction and obje...

Design of small fishing vessels

Abstract: Part 1 Preliminary design: background information for the student designer design procedures economics in fishing vessel design. Part 2 General design procedures - hydrodynamics, hull form and powering: hydrostatic calculations and and hydrostatic curves weights and centre of gravity calculations stability of small fishing vessels resistance, powering and propellor selection scantling determination. Part 3 Specific design requirements for fishing vessels: regulations, codes and conventions concerning fishing vessel design fishing equipment engine installations deck outfit and equipment, internal accommodation fish hold construction and methods of fish preservation design specification, contract parameters, cost estimation.

AN ECOWGICAL SURVEY AND COMPARISON OF BotTOM FISH RESOURCE ASSESSMENTS (SUBMERSIBLE VERSUS HANDLINE FISHING) AT JOHNSTON ATOLL

Abstract: The deep slope (100-365 m) environment at Johnson Atoll in the central Pacific was surveyed with a submer­ sible and the standing crop of r.ommercially important bottom fishes (i.e., lutjanids. serranids. and carangids) estimated by visual quadrat censusing. Results are compared with an assessment made by hook-and-line fishing. Overall, 69 species of fish were recorded from the submersible and 10 from fishing. Well over half of the sightings from the submersible were new locality records. Bottom fish abundance estimates (fishlhee­ tare and fishlline-hour) varied by site but agreed broadly with one another. 'Ibgether they are used to estimate catchability (0.0215 hectarelline-hourl, which is shown to vary through the day. Bottom fish were contagiously dispersed along both vertical and horizontal dimensions, with increased numbers of the snapper Pr~tipo'moid<'8ji.la7llelltosU$ in upcurrent localities. On a finer scale this species and Et-eI.UI CO'l'lt8Ca718 were aggregated near underwater promontories and headlands, but at different depths. Numerous observations concerning the deep slope environment of this central Pacific Ocean atoll are included.

Biology and Management of the Lake Sturgeon in the Moose River, Ontario

Abstract: The age and growth of lake sturgeons (Acipenser fulvescens) were investigated in the lower Moose River system in the Hudson Bay lowland. The effects of current fishing methods also were reviewed in order to recommend procedures for a sustained-yield fishery. The population estimate of lake sturgeon in the study area was 7,088 with 95% confidence limits of 5,774-8,919. Sex ratios of all fish sampled throughout the summer were 1:1 and the length-weight relationship showed allometric growth with no significant differences between sexes. The age of first spawn for females was approximately 20 years but that for males was suspect due to small sample sizes of ripe males. Tissue mercury analyses showed relatively high levels of mercury in lake sturgeons longer than 102 cm. Growth was calculated from the Brody-Bertalanffy relationship that was employed in the Beverton-Holt yield model. This model indicated that increases in fishing intensity under present fisheries regulations would result in overexploit...

Optimal Effort Allocation Among Competing Mixed-Species Fisheries, Subject to Fishing Mortality Constraints

Abstract: A linear programming (LP) approach to effort allocation among two or more fisheries (fleets) exploiting several common species/stocks is described and applied to otter trawl fisheries exploiting de...

finding fish: the tactics of Icelandic skippers

Abstract: We discuss the literature on decision making in fishing and describe several objective factors related to Icelandic fishing skippers' behavior regarding times and destinations of their fishing trips. We argue that the information available to them and the knowledge and theories they have developed often can lead them to several different conclusions. They therefore follow hunches and other processes of decision making. We develop a statistical analysis of data on fishing locations in order to be able to describe the behavior, but not the cognition, of these skippers. [fishing, decision making, Iceland, skipper effect, statistics]

The ecology of lucayan arawak fishing practices

Abstract: Fishing is a form of predator-prey interaction. As such, the behaviors of fishes can be used to define a restricted range of human behaviors that resulted in their capture. In this report, ecological evidence, fishbone analysis, ethnohistoric reports for the prehistoric Caribbean, experimental fishtrap samples, and ethnographic reports of fishing in other coral waters are brought together in the analysis ofprehistoric fishing in the Bahama Archipelago. The analysis is conducted at two levels. First, generalfishing strategies are distinguished on the basis of behavioral evidence; and second, specific capture techniques are identified through comparisons with experimental fishtrap samples.

A variable catchability version of the leslie model with application to an intensive fishing experiment on a multispecies stock

Abstract: A variable catchability version 'of the Leslie model is developed which permits the catchability of one species to vary inversely with the abundance of competing species. This model is used to fit data from an intensive fishing experiment conducted on a multispecies bottom fish stock in the Marianas where catchability of a subordinate species is inversely related to the abundance of a more dominant species. Analysis of this multispecies intensive fishing experiment produced estimates ofexploitable bottom fish density in the 150-275 m depth range of 10,156 fish per nmi 2 or 1,354 fish per nmi of 183 m (100-fathom) contour.

Decline in Natural Fisheries — A Genetic Analysis and Suggestion for Recovery

Abstract: Overfishing and pollution of the aquatic environment, in addition to their direct effects on natural fisheries, may have also influenced natural fish populations genetically. Overfishing drastically reduces population size and, since the larger individuals are selectively removed, is equivalent to selection for smaller sized fish. Adaptation of natural fish populations to their environment must have been reduced by rapid environmental changes resulting from pollution and infestation. Inbreeding, negative selection, and lack of adaption are here considered as the genetic causes for the decline of natural fisheries and lack of recovery. Restocking programs involving hatchery stocks are unlikely to solve this problem, since these stocks were selected for adaptation to hatchery environments and not to natural environments. A series of studies have demonstrated heterosis of interstrain crossbreds, mainly between hatchery and wild stocks of salmonids, for performance in natural waters. Two strategies could be i...

Problems and Perspectives Regarding Recruitment of Spiny Lobsters, Panulirus argus, to the South Florida Fishery

Abstract: Inappropriate minimum size, illegal harvest, fishery-induced juvenile growth retardation and mortality, and excessive effort have reduced reproductive contributions and depressed yield-per-recruit in the overcapitalized south Florida spiny lobster (Panulirus argus) fishery. Measures recommended to improve yield-per-recruit are as follows: increase minimum legal size to 85–90 mm carapace length; require escape gaps in traps; eliminate possession of sublegal lobsters aboard vessels; prohibit harvest in nurseries; reduce fishing effort; improve enforcement of fishery regulations; and initiate programs to educate fishermen regarding impacts of fishery practices. International management is recommended to assure larval recruitment among Pan-Caribbean stocks.

The demersal fishery in the Clyde Sea Area

Abstract: Data from the Clyde demersal fishery during the period 1960 to 1984 are presented. Annual landings of demersal species at Chde ports in recent years have ranged from 4000 to 10,000 tonnes, with a first sale value of £2–5 million. In the 1960s the fishery was undertaken mainly by seine-net vessels, but the present fleet consists largely of dual-purpose light/Nephrops trawlers. The demersal fishery is seasonal and during the winter and spring there is an influx of ‘stranger’ vessels. Five species (cod, whiting, saithe, hake and haddock) make up more than 80% of the demersal landings from the Clyde. The landings of saithe have fluctuated very considerably during the period under review. Other relatively important species are dogfish, plaice, skate and ray and angler fish. In general the Clyde fishery represents only a small proportion of the total Scottish landings but in recent years landings of hake from the Clyde grounds have averaged approximately 40% of the Scottish hake total. The Clyde demersal fishery depends to a large extent on young fish and both the total annual landings and the relative importance of the principal species fluctuate from year to year in response to variations in the strength of the recruiting year classes. The catch rates of the principal species vary greatly throughout the year. Although there is no conclusive evidence that the Clyde populations are self-contained, all the major species are known to spawn within or close to the area and tagging experiments have suggested that there may not be much mixing between Clyde fish and those from surrounding areas. This may in part, however, reflect the fact that fishing intensity within the Clyde is high and fish are recaptured before they have had time to leave the area. For management purposes, the Clyde demersal stocks are included in ICES Sub-area VI.

Changes in Mean Weight, Sea-Age Composition, and Catch-per-Unit-Effort of Atlantic Salmon (Salmo salar) Angled in the Godbout River, Quebec, 1859–1983

Abstract: A weight-age classification, based on recent catches, was retroactively applied to angled Atlantic salmon (Salmo salar) catches recorded in the log of the Godbout salmon club between 1859 and 1983. Over this period, numbers of salmon caught have fluctuated with a periodicity of 20–30 yr but catches have been maintained. There has been a big increase in fishing effort, and the proportion of two-sea-year to previously spawned fish has increased. The mean weight of these age groups has declined 0.005–0.009 kg∙yr−1. These changes are attributed to the selective effects of commercial fisheries on the stock.

Exploited fish and shellfish species in the Moray Firth

Abstract: The Moray Firth has been intensively fished for many years and has been of great historic importance to the development of Scottish fisheries. The stocks of exploited species in the firth and their relations to other stocks in Scottish waters are described.Exploited demersal species include haddock, cod, whiting, plaice and lemon sole. The firth is an important nursery area for plaice, and is the most important plaice spawning ground in the North Sea.The Moray Firth is also an important nursery area for herring. Evidence suggests that these fish recruit to adult stocks in the Minch. In the early 1960s a pair trawl fishery for sprats started and the firth became the most important sprat fishing area in Scotland. However, recruitment of recent year classes has been too poor to sustain the fishery, which has now been closed in order to protect the juvenile heiring which were landed as by-catch.The distributions of shellfish species are closely related to the bottom sediments. Landings have become increasingly important as the demersal and pelagic fisheries have declined or moved further offshore. The fishery on the Norway lobster is now of particular importance and the catch per unit effort data do not suggest any decline in stock size. Other exploited species include squid, scallops, crabs and lobster.

Incidental mortality of dolphins in the eastern tropical pacific, 1959·72

Abstract: The estimates of the number of dolphins killed annually from the beginning of the US. tuna purse seine fishery in the eastern tropical Pacific are used by the National Marine Fisheries Service in developing management advice for the US. purse seine fleet. We estimated the annual number of dolphins killed incidentally in the tuna purse seine fishery for 1959-72. Kill data were available for only a few years prior to 1970. Because no obvious trend was shown with the existing data, kill rates were averaged over those years and stratified by various categories: large and small vessels, sets with large catch of tuna and small catch of tuna, sets which used backdown (a dolphin-releasing procedure), and sets which did not use backdown. These kill rates, combined with estimated number of sets, produced the estimated annual kills. Because data were available only for some of the years, they had to be pooled to obtain annual estimates. As a result, the annual estimates were highly correlated. Because the total as well as the annual estimates are of interest, it is necessary to compute the variance-covariance of the estimated annual kills. The annual kill from 1959 to 1972 varied from 55,000 in 1959 to 534,000 in 1961. There were three distinct maxima of 534,000, 460,000, and 467,000, corresponding to peaks in number of sets made on dolphins in 1961, 1965, and 1970. The total kill from 1959 to 1972 was estimated to be about 4.8 million, with a coefficient of variation of 17%. The eastern tropical Pacific tuna purse seine fleet began to develop rapidly in the late 1950’s and has grown to over 100 U.S.-registered vessels and a substantial number of non-US.-registered vessels in recent years. This fleet fishes primarily for yellowfin tuna, Thunnus albacares, and skipjack tuna, Katsuwonus pelamis. Majority of the yellowfin tuna are taken while the tunas are schooling with dolphins primarily of the species Stenella attenuata and S. longirostris. Birds and dolphins are frequently used as cues in finding the tuna. During the capture of the tuna, some of the dolphins are killed or drowned by becoming tangled in the net webbing (Perrin 1969). The number of dolphins killed has been estimated to have been greater than one-half million in some of the years in the 1960’s (Smith 1983). Currently, fewer animals are killed each year due to improvements in the fishing gear and in procedures to release dolphins. Estimates of the total number of dolphins killed each year in this fishery are used as a basis for management advice by the National Marine Fisheries Service (NMFS). In this paper we describe in detail the method used in Smith (1983), including

Red crab (Geryon maritae) density in 1985 by the technique of effective area fished per trap on the northern fishing grounds off South West Africa

Abstract: The mean effective fishing area (EFA) of a Japanese-type crab trap fishing for Geryon maritae on the northern South West African red-crab grounds was calibrated as 2 160 m2. The commercial fishery uses traps covered with 90-mm mesh. In order to be able to use the density results obtained by this survey from traps covered with 60-mm mesh, a preliminary mesh selectivity study was carried out. The carapace width at 50-per-cent retention for 90-mm mesh was estimated as 72 mm. Based on the EFA results, it seems that most commercial fishing takes place in areas of crab density varying between 46 and 231 crabs·ha−1, but that densities can reach ∼510 crabs·ha−1. It is suggested that crab traps would fish more efficiently on the northern South West African crab grounds if longlines were set across the depth contours rather than in a longshore direction.

Boat fishing organizer formed as basket-like structure with attachment means for fishing accessories

Abstract: The present invention relates to a boat fishing organizer wherein a plurality of objects and implements which are used when fishing from a boat may be conveniently stored and organized for easy availability and use. The device includes a basket-like receptacle having hooks thereon so that it may be mounted on the gunwhale of the boat. Attached to the receptacle portion are loops to store a fishing net, a device for storing an extra spool of fishing ine, an elongated bar on which hooks and sinkers may be removably attached and a device for supporting in an upright angular orientation a fishing rod. The receptacle portion may be used to store various items including a tackle box.

Regional Impacts of Fishery Allocation to Sport and Commercial Interests: A Case Study of Ohio's Portion of Lake Erie

Abstract: The economic impacts of increased reallocation of Ohio's Lake Erie fishery from commercial fishing to sportfishing were examined with an input-output model of northern Ohio for 1978. With the growing popularity of sportfishing, sport anglers generate greater political pressure than do commercial fishermen for use of the limited resource. Sport anglers are already the only harvesters of walleye (Stizostedion vitreum) in Ohio. Added reallocations would only make additional yellow perch (Perca flavescens) and white bass (Morone chrysops) available. The model shows that the impacts of sportfishing on output, income, and employment are greater per unit of fish than the impacts of commercial fishing. However, the sportfishing sector in the model is dominated by summer walleye fishing. The reallocated yellow perch are primarily harvested in the autumn. Research on the response of sport anglers to the 1984 purchase of gill-net fishing rights is needed to determine if expenditures increase sufficiently to...

Implications of Private Salmon Aquaculture on Prices, Production, and Management of Salmon Resources

Abstract: The emergence of large‐scale salmon ranching in the Pacific Northwest has led to significant controversy over the potential impact of salmon ranching on market structure, salmon prices, ocean and aquacultural production, and salmon fishing regulation. This paper models the behavior of a dominant salmon rancher facing a competitive open‐access fishery using a dynamic nonlinear programming model. Primary attention is given to production and regulation‐influencing strategies of an optimally managed salmon ranch under selected institutional and biological constraints. The effect of such behavior is evaluated with regard to salmon prices, natural salmon stocks, ocean fishing effort, and ocean fishery productivity.