نتایج جستجو برای: fishing effort

تعداد نتایج: 129837  

2005
K. A. Koranteng D. Pauly

A brief review is presented of the structure of the Ghanaian fishing fleet, and of the changes they induced on their resource base since the 1960s. These change consist of a reduction of the biomass of longer lived fishes, particularly in shallower waters, and in conjunction with environmental fluctuation, the creation of opportunities for invasive species of fish (triggerfish Balistes caroline...

2004
Robert Repetto James Gustave Speth

The Atlantic sea scallop fisheries in the U.S. and Canadian o≠shore waters provide a natural experiment in fisheries management regimes. Starting in 1986, in side by side areas of George’s Bank, Canada adopted a rights-based approach while the U.S. continued with effort controls. Analysis of their experiences shows that the resource has been better maintained in Canada with lower fishing e≠ort,...

2008
Carlos Chávez Nuria González Hugo Salgado

We study an individual transferable quota system with imperfect enforcement. We apply a model of individual fisherman behavior to the red shrimp (Pleuroncodes monodon) fishery in central-southern Chile. Simulation results suggest that illegal fishing could generate a 21% increase in fishing effort, resulting in a 13% increase in catch and a 2% lower quota price in comparison with the results of...

Journal: :SIAM J. Control and Optimization 2009
Alberto Bressan Wen Shen

Abstract. In this paper we study a model for the harvesting of marine resources, described by an elliptic equation. Since the cost functionals have sublinear growth w.r.t. the pointwise intensity of fishing effort, optimal solutions are in general measure-valued. For the control problem, we prove the existence of optimal strategies. Uniqueness is established within a class of measures with smal...

2015
Samuel M. Williams Bonnie J. Holmes Julian G. Pepperell Timothy Darren Clark

Increasing fishing pressure and uncertainty surrounding recreational fishing catch and effort data promoted the development of alternative methods for conducting fisheries research. A pilot investigation was undertaken to engage the Australian game fishing community and promote the non-lethal collection of tissue samples from the black marlin Istiompax indica, a valuable recreational-only speci...

Journal: :Basic and Applied Sciences - Scientific Journal of King Faisal University 2021

Journal: :Ambio 2002
Randall A Kramer Sahat M H Simanjuntak Christopher Liese

The coastal ecosystems in Southeast Asia are under increased pressure from local and global change. This paper examines human migration and the use of marine resources in coastal villages in the Minahasa district of North Sulawesi, Indonesia. Primary data were collected through interviews with village leaders, focus groups, and a sample survey of 600 fishing households. Migration is responsible...

2003
Francis Laloë

In a letter to Nature, Myers and Worm present, for a wide range of oceanic ecosystems, an analysis of catches per unit of effort (CPUE) data, leading them to the conclusion of “a rapid worldwide depletion of predatory fish communities”: After a sharp initial reduction, CPUE appears stable since more than twenty years at a level of about 10% of their initial value. Such a result makes quite evid...

Reza Abaspour Naderi, Seyed Hesam Kazemi, Seyed Yousef Paighambari,

The present study aims to recognize dhow prawn trawl by-catch from Hormuzgan coastal waters (Northeast Persian Gulf). Sampling was carried out of 36 hauls by using traditionally wooden dhow among prawn fishing season in 2011. The catch composition consisted of 31.66% target species prawns, mainly banana prawn (Penaeus merguiensis) and 68.34% by-catch. The total by-catch was 4,622.67kg com...

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