نتایج جستجو برای: fishing effort
تعداد نتایج: 129837 فیلتر نتایج به سال:
This paper considers regulation formation in a fishery where the aggregate harvest level is fixed. Fishing captains and input suppliers participate in the process under which regulatory instruments such as capital restrictions, entry restrictions, or individual transferable quotas (ITQs) are chosen. The feasible set of regulations must satisfy two constraints: an upper bound on the season lengt...
The interaction between multiple stressors on Caribbean coral reefs, namely, fishing effort and hurricane impacts, is a key element in the future sustainability of reefs. We develop an analytic model of coral-algal interactions and explicitly consider grazing by herbivorous reef fish. Further, we consider changes in structural complexity, or rugosity, in addition to the direct impacts of hurric...
With the overexploitation of many conventional fish stocks, and growing interest in harvesting new kinds of food from the sea, there is an increasing need for managers of fisheries to take account of interactions among species. In this work we define a bioeconomic equilibrium model for ’n’ fishermen who catch three species; these species compete with each other for space or food. The natural gr...
Fisheries bycatch is a worldwide conservation issue. Despite a growing awareness of bycatch problems in particular ocean regions, there have been few efforts to identify spatial patterns in bycatch events. Furthermore, many studies of fisheries bycatch have been myopic, focusing on a single species or a single region. Using a range of analytical approaches to identify spatial patterns in bycatc...
Understanding how fishers make decisions is important for improving management of fisheries. There is debate about the extent to which small-scale fishers follow an ideal free distribution (IFD) - distributing their fishing effort efficiently according to resource availability rather than being influenced by social factors or personal preference. Using detailed data from 1800 fisher catches and...
The scope of this paper is to describe, evaluate, and forecast fishing trip choices of the Bay of Biscay pelagic fleet using random utility modeling (RUM). First, alternative fishing trip choices of this fleet were identified using multivariate statistical methods based on species landings weighted by value and defined as distinct fishing activity or fisheries (termed métiers). A RUM was specif...
We used a process-oriented model (Ecosim) to characterize changes in marine resources in the north-central (NC) Adriatic Sea (Mediterranean) from 1975 to 2002, and to explore the extent to which these changes were driven by trophic interactions, environment and fishing. Fishing efforts and fishing mortalities were used to drive the ecosystem model, and available biomass and catch data were comp...
In most cases authors are permitted to post their version of the article (e.g. in Word or Tex form) to their personal website or institutional repository. Authors requiring further information regarding Elsevier's archiving and manuscript policies are encouraged to visit: a b s t r a c t a r t i c l e i n f o Keywords: Common-pool resources Collective action Social–ecological systems Small-scal...
This paper uses data from an actual fishery to construct a tractable, dynamic model to compare expected profit and its variance, optimal stock size, optimal harvest rate, and optimal fishing effort under different management regimes under uncertainty. The results provide a comparison of instrument choice between a total harvest control and a total effort control under uncertainty, an original m...
Despite increasing reports of fisheries collapses world wide, investigations of the effects of fishing on the global marine environment have been constrained by the paucity of fisheries landings data on suitable spatial scales. Working to overcome this, we have developed new databases and approaches that demonstrate basin-scale reductions in biomass and landings due to intensifying fishing effo...
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