scholarly journals Fisheries management in the face of uncertainty: Designing time-area closures that are effective under multiple spatial patterns of fishing effort displacement in an estuarine gill net fishery

PLoS ONE ◽  
2019 ◽  
Vol 14 (1) ◽  
pp. e0211103 ◽  
Author(s):  
Liza A. Hoos ◽  
Jeffrey A. Buckel ◽  
Jacob B. Boyd ◽  
Michael S. Loeffler ◽  
Laura M. Lee
Keyword(s):  
Spatial Patterns ◽  
Fisheries Management ◽  
Fishing Effort ◽  
Gill Net ◽  
The Face

Keynote Address

1973 ◽  
Vol 30 (12) ◽  
pp. 1931-1934
Author(s):  
F. E. Popper
Keyword(s):  
Fisheries Management ◽  
Technical Conference ◽  
Keynote Address ◽  
Rate Of Growth ◽  
Efficient Management ◽  
The World ◽  
Management And Development ◽  
The Face ◽  
Fish Catch ◽  
Increasing Demand

The contribution made by Canada in providing the means for the Technical Conference was gratefully acknowledged, and the terms of reference were summarized as approved by Council of the FAO. Briefly, these are — to discuss the scientific and technical means of solving problems and reaching objectives in fisheries management and development. Significant problems that have become evident since the UN Conference in 1955 are: an urgent need for management of most of the traditionally fished stocks; decreasing rate of growth of the world fish catch in the face of increasing demand; economic interactions from greatly intensified fisheries and fishing enterprises; importance of development in relation to management. The need to take the long view in approaching these problems was emphasized, as well as the great value to be derived from recognition of existing deficiencies in organizations or methods. Universally acceptable rules for control of fisheries, and participation by all nations in supplying fisheries data essential for efficient management, are obvious requirements of high priority.

Benthic Habitats and the Effects of Fishing

2005 ◽  
Keyword(s):  
Fisheries Management ◽  
Large Scale ◽  
Scale Effects ◽  
Ecosystem Processes ◽  
Fishing Effort ◽  
Habitat Types ◽  
Benthic Habitats ◽  
Management Actions ◽  
Ecosystem Effects ◽  
Ecosystem Based Fisheries Management

<strong><em>Abstract. </em></strong>We review the impacts of towed gears on benthic habitats and communities and predict the consequences of these impacts for ecosystem processes. Our emphasis is on the additive and synergistic large-scale effects of fishing, and we assess how changes in the distribution of fishing activity following management action are likely to affect production, turnover time, and nutrient fluxes in ecosystems. Analyses of the large-scale effects of fishing disturbance show that the initial effects of fishing on a habitat have greater ecosystem consequences than repeated fishing in fished areas. As a result, patchy fishing effort distributions have lower total impacts on the ecosystem than random or uniform effort distributions. In most fisheries, the distribution of annual fishing effort within habitats is more patchy than random, and patterns of effort are maintained from year to year. Our analyses suggest that many vulnerable species and habitats have only persisted in heavily fished ecosystems because effort is patchy. Ecosystem-based fisheries management involves taking account of the ecosystem effects of fishing when setting management objectives. One step that can be taken toward ecosystem-based fisheries management is to make an a priori assessment of the ecosystem effects of proposed management actions such as catch controls, effort controls, and technical measures. We suggest a process for predicting the ecosystem consequences of management action. This requires information on habitat distributions, models to predict changes in the spatial distribution of fleets following management action, and models of the impacts of trawling disturbance on ecosystem processes. For each proposed management action, the change in disturbance affecting different habitat types would be predicted and used to forecast the consequences for the ecosystem. These simulations would be used to produce a decision table, quantifying the consequences of alternative management actions. Actions that minimize the ecosystem effects of fishing could then be identified. In data-poor situations, we suggest that management strategies that maintain or maximize the patchiness of effort within habitat types are more consistent with the precautionary approach than those that lead to more uniform fishing effort distributions.

Incidental capture of elasmobranchs in the bottom-set gill-net fishery off the south coast of Ireland

1994 ◽  
Vol 74 (4) ◽  
pp. 837-847 ◽  
Author(s):  
S.D. Berrow
Keyword(s):  
Fishing Effort ◽  
South Coast ◽  
Fishing Gear ◽  
The South ◽  
Blue Shark ◽  
Incidental Capture ◽  
Gill Net ◽  
Total Capture ◽  
Catch Rates ◽  
Basking Shark

The incidental capture of sharks in the bottom-set gill-net fishery off the south coast of Ireland was quantified by placing observers on commercial gill-netters for the duration of a fishing trip. Forty fishing trips were sampled resulting in 1,167 km and 19,760 km h of observed fishing effort. Sixty individual sharks of seven species were reported entangled in the fishing gear. Tope, porbeagle and six-gilled sharks were the most frequently caught species, with black-mouthed dogfish, blue shark, basking shark and starry smooth hound also recorded. Total fishing effort along the south coast was calculated and total capture extrapolated from observed catch rates. An estimated 6,000 sharks were caught in this fishery during the study period.

scholarly journals Costs and Returns of Fishermen in the Massachusetts Inshore Lobster Fishery

1975 ◽  
Vol 4 (2) ◽  
pp. 195-210 ◽  
Author(s):  
J. M. Gates ◽  
J. M. D'Eugenio
Keyword(s):  
Fisheries Management ◽  
Fishing Effort ◽  
The State ◽  
Economic Factors ◽  
Sufficient Criterion ◽  
Fish Stocks ◽  
The Past ◽  
Resource Managers ◽  
Lobster Fishery

The inshore lobster fishery is one of the more important ones in the Commonwealth of Massachusetts, accounting for approximately 14 percent of the total landed value of all species in Massachusetts in 1971. Until recent years this fishery accounted for virtually all the pot landings in the state. Despite numerous attempts at conservation such as gear regulation, size restrictions, and prohibitions on harvesting egg-bearing females, the fishery has been subject to rapidly increasing effort and virtually constant landings. In the past decade it has become obvious to many fishery biologists and economists that conservation of fish stocks is a necessary but not sufficient criterion for fisheries management. Resource managers have become increasingly aware of the interdependence between economic factors and the intensity, location and composition of fishing effort.

A POLICY OF FISHERIES MANAGEMENT BASED ON CONTINUOUS FISHING EFFORT

2001 ◽  
Vol 09 (04) ◽  
pp. 247-254 ◽  
Author(s):  
M. JERRY ◽  
N. RAISSI
Keyword(s):  
Equilibrium Point ◽  
Fisheries Management ◽  
Optimal Strategy ◽  
Fishing Effort ◽  
Asymptotical Stability

This work is composed by two parts: the first part consists of the development and the analysis of a bioeconomical model of fisheries management, where the dynamic is controlled by the variation of the fishing effort; the second part of this work consists of the study of the asymptotical stability of the equilibrium point (stock/fishing effort) of the model; the optimal strategy is described briefly.

Shark fisheries in Argentina

1998 ◽  
Vol 49 (7) ◽  
pp. 601 ◽  
Author(s):  
Gustavo E. Chiaramonte
Keyword(s):  
Fishing Effort ◽  
Population Trends ◽  
The South ◽  
Gill Nets ◽  
Argentine Sea ◽  
Commercial Importance ◽  
South West ◽  
Gill Net ◽  
Galeorhinus Galeus ◽  
Mustelus Schmitti

In the Argentine Sea there are about 35 species of sharks. Three species are subjected to directed fishing: the smoothhound Mustelus schmitti, the school shark Galeorhinus galeus and the copper shark Carcharhinus brachyurus. Other species of elasmobranchs with commercial importance are the angel shark Squatina spp. and several species of skates and rays. The rise in chondrichthyan declared landings registered from 1988 to 1996 is due to the increase in landings of smoothhound and rays. The most important directed shark fishery in the South-West Atlantic is the Necochea gill-net fishery for school shark, which is carried out by the coastal fleet; details are given of the ships and the gill-nets used in this area. The length frequencies of the catches by gill-nets are presented for the school shark; fishing effort (length (km) of net in the water per ship per day) and CPUE (number of sharks per fishing effort) were found not to be good indicators of population trends in the school shark fishery. Resumen. En el Mar Argentino se han registrado 35 especies de tiburones. Tres de estas especies están sometidas a una pesca dirigida; el gatuzo, Mustelus schmitti, el cazón, tiburón vitamínico o trompa de cristal, Galeorhinus galeus y la bacota, Carcharhinus brachyurus. Otras especies de elasmobranquios de importancia comercial son el pez ángel Squatina spp. y algunas especies de rayas. El incremento en los desembarcos de condríctios declarados a las autoridades pesqueras entre 1988 y 1996 es debido principalmente al incremento del desembarco de gatuzo y rayas. La pesquería dirigida a tiburón más importante en el Atlántico Sudoccidental es la pesquería costera de enmalle de Necochea para el cazón. Se describen el largo de las embarcaciones y las redes utilizadas en el área (la medida de malla, el calado y la operación del arte de pesca). Se presenta la frecuencia del largo total de las capturas de cazón en redes de enmalle. Se halló para la pesquería del cazón que el esfuerzo pesquero (estimado como km de red en el agua por embarcación por día) y la CPUE (estimada como tiburones/esfuerzo de pesca) no son buenos indicadores de la tendencia en la abundancia poblacional.

A Bayesian spatiotemporal approach to inform management unit appropriateness

2019 ◽  
Vol 76 (2) ◽  
pp. 217-237 ◽  
Author(s):  
Rujia Bi ◽  
Yan Jiao ◽  
Can Zhou ◽  
Eric Hallerman
Keyword(s):  
Great Lakes ◽  
Fisheries Management ◽  
Yellow Perch ◽  
Management Strategies ◽  
Computational Cost ◽  
Bayesian Hierarchical ◽  
Fish Stocks ◽  
Spatiotemporal Correlation ◽  
Management Actions ◽  
Gill Net

One prerequisite for sustainable fisheries management is to match management actions with biological processes. Stocks are fundamental units for fisheries management. Understanding the spatial structure of fish stocks is critical for conducting defensible stock assessments, applying efficient management strategies, and ensuring the sustainability of fish stocks. Yellow perch (Perca flavescens) is an important fishery in the Great Lakes. The appropriateness of its management units (MUs) has been identified as of high concern by the Great Lakes Fisheries Commission. Here we established integrated nested Laplace approximations and stochastic partial differential equations as two powerful tools for modeling spatiotemporal patterns of fish relative biomass. These fast computational approaches were applied to fit a Bayesian hierarchical hurdle model to occurrence and positive mass of yellow perch caught in gill-net surveys. Yellow perch relative biomass index has clear temporal variation and spatial heterogeneity, with the two middle MUs for yellow perch within Lake Erie merging together. The method explicitly models the spatiotemporal correlation structure inherent in biomass survey data at a reasonable computational cost, and the estimated spatiotemporal correlation informs stock structure.

Preliminary results of a study into the incidental mortality of sharks in Gill-nets in two Tasmanian Shark Nursery Areas

1992 ◽  
Vol 43 (1) ◽  
pp. 237 ◽  
Author(s):  
H Williams ◽  
AH Schaap
Keyword(s):  
Relative Abundance ◽  
Fishing Effort ◽  
Shark Species ◽  
Nursery Areas ◽  
Preliminary Results ◽  
Gill Net ◽  
Galeorhinus Galeus ◽  
Potential Rate ◽  
Incidental Mortality ◽  
Gill Netting

Since the early 1960s, certain sheltered bays and estuaries around Tasmania have been designated shark nursery areas, where the taking of either the school shark (Galeorhinus galeus) or the gummy shark (Mustelus antarcticus) has been prohibited. Recent assessments of Australian stocks of school and gummy sharks indicate that they are close to collapse, and the management of the fishery has come under review. With respect to shark nursery areas, concern has focused on the potential rate of incidental mortality of sharks caused by recreational gill-net fishing and poaching. In 1990, a study was begun in Frederick Henry Bay and Norfolk Bay, the largest proclaimed shark nursery areas in Tasmania, to estimate recreational net-fishing effort and incidental captures of sharks. School sharks were caught in waters deeper than 5 m; gummy sharks and dogfish were caught at all depths. The diversity and relative abundance of shark species increased with depth, whereas the diversity of teleosts decreased with depth. Most captured school and gummy sharks were between 1+ and 3+ years of age. Preliminary estimates of potential incidental mortality demonstrate that gill-netting in depths greater than 5 m may be a significant source of mortality for both species.

KAPASITAS PENANGKAPAN IKAN PELAGIS KECIL DI PERAIRAN PANTAI BARAT SULAWESI SELATAN (FISHING CAPACITY OF SMALL PELAGIC FISH IN OF WEST COAST OF SOUTH SULAWESI)

2016 ◽  
Vol 1 (2) ◽  
pp. 117 ◽  
Author(s):  
Alfa Nelwan
Keyword(s):  
West Coast ◽  
Fishing Effort ◽  
Pelagic Fish ◽  
Production Data ◽  
Fish Production ◽  
Beach Seine ◽  
Small Pelagic Fish ◽  
South Sulawesi ◽  
Gill Net ◽  
Development Analysis

Kapasitas penangkapan adalah ukuran kemampuan yang dikerahkan oleh berbagai jenis unit penangkapan ikan yang tergabung sebagai suatu armada penangkapan ikan untuk memperoleh hasil tangkapan. Penelitian ini menganalisis trend dan kapasitas penangkapan ikan pelagis kecil di perairan pantai barat Sulawesi Selatan. Delapan jenis alat penangkap yang signifikan di Selat Makassar, perairan barat Provinsi Sulawesi Selatan adalah payang, pukat pantai, pukat cincin, jaring insang hanyut, jaring lingkar, jaring insang tetap, bagan perahu dan bagan tancap.  Produksi dari 8 unit penangkapan berdasarkan 6 jenis ikan pelagis kecil, yaitu (1) kembung (Rastrelliger sp), (2) layang (Decapterus sp), (3) lemuru (Sardinella longiceps), (4) selar (Selaroides spp), (5) tembang (Sardinella  fimbriata), (6) teri (Stolephorus spp). Total upaya penangkapan ikan tahunan dari kedelapan jenis unit penangkapan ikan tersebut dihitung untuk kurun waktu selama 20 tahun (1987-2006) dengan menerapkan standardisasi berdasarkan kemampuan setiap jenis unit penangkapan ikan.  Analisis dilakukan untuk mengidentifikasi trend CPUE dan kapasitas penangkapan ikan pelagis kecil menggunakan metode Peak to Peak Analysis di tiga zona perairan pantai, yaitu perairan laut dangkal  (zona A), perairan bentuk teluk (zona B) dan perairan laut dalam (zona C), Tren CPUE di ketiga zona menunjukkan cenderung menurun dalam kurun waktu 30 tahun, dimana tren menurun CPUE di zona C menunjukkan lebih besar dibandingkan zona lainnya.  Kapasitas penangkapan di zona A, perlu mereduksi jumlah unit penangkapan sebesar 6%, sedangkan di zona B sebesar 5% dan zona C sebesar 11% untuk mencapai produksi optimal.Fishing capacity can be regarded as a total mobilized capability made by fishing fleet to produce catch. This research analyze trend and fishing capacities of small pelagic fish in off west coast of South Sulawesi. There are 8 significant fishing unit operated in off west coast of South Sulawesi ; these are  payang, beach seine, purse seine, drift gill net, encircling gillnet, fixed gill net, boat liftnet, fixed liftnet.  The fish production data cover 6 types of fish, i.e. Indian mackerel, anchovy, sardines, scads, and trevally caught by 8 types fishing unit. Annual fishing effort and CPUE over a period of 30 years (1977-2006) were calculated after a standardization considering variability in capture capability and fisheries development.  Analysis was conducted for identifyng CPUE trend and fishing capacities of small pelagic fish using Peak to Peak Analysis. The study area was divided into three regions, i.e, around Spermonde Island  (zone A), off Polman and Pinrang district (zone B) and off Majene dan Mamuju district (zone C).  CPUE trend in three water zone showed to decrease for 30 year of period, where decreasing CPUE trend at zone C was higher than other zones.  Fishing capacities in zone A need to be reduced of fishing effort for  6%, whereas in zone B was 5% and zone C was 11%.

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