Balanced feed represents approximately 60 % of production costs in fish culture and ration size has significant effects on this parameter. Ration size varies according to culture strategies and producer knowledge. It can also have environmental implications since feed can be a pollutant. A bioeconomic model was developed for an...
Des comptes d'exploitation par type d'exploitation de la flottille aux céphalopodes sont utilisés dans la modélisation bio-économique qui met a notre disposition des éléments d’appréciations plus centres sur des variables économiques. Ces éléments servent a des taux d'exploitation optimaux selon les critères juges pertinents par 1'adniinistration (revenus. Emploi, etc.) et...
This study investigates optimal catch of Barents Sea stocks, namely Northeast Arctic Cod and Capelin in multispecies ecosystem. We solve a multispecies age structured bioeconomic model for predator-prey interaction. Barents Sea stock data from ICES are employed for model application. Among others, we also include sustainability constraint in the model...
In this paper, a dynamic model of fishermen’s compliance is developed and used to analyse
several issues. There are two parties involved in the fishery; the regulator and the fishermen.
Regulator takes on a long term view and sets quota at the beginning of every period in order
to maximise...
The central objective of fishery management is to ensure the sustainability and profitability of the resource base. The
importance of the fish stock's age-structure is increasingly recognized in economics and ecology. Still, current
policies predominately rely on the aggregate biomass. We carefully calibrate a detailed model on the North-East
Arctic...
The World Summit on Sustainable Development (Johannesburg, 2002)
encouraged the application of the ecosystem approach by 2010.
We propose a framework that deals jointly with i) ecosystem dynamics,
ii) conflicting issues of production and preservation and
iii) robustness with respect to dynamics uncertainties.
More specifically, we define robust viability kernels...
The World Summit on Sustainable Development (Johannesburg, 2002)
encouraged the application of the ecosystem approach by 2010.
We propose a framework that deals jointly with i) ecosystem dynamics,
ii) conflicting issues of production and preservation and
iii) robustness with respect to dynamics uncertainties.
More specifically, we define robust viability kernels...
The aim of this work is to develop a predator-prey model for two species of commercial importance captured by the Spanish fishing fleet in the National Fishing Ground (ICES areas VIIIc and IXa). In this model, the Southern hake (Merluccius merluccius) represents the predator, and the blue whiting (Micromesistius poutassou)...
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bioeconomic model to
solve it.
Brown, G., Berger, B. and Ikiara, M. 2005. A Predator-Prey
Model
The aim of this work is to develop a predator-prey model for two species of commercial importance captured by the Spanish fishing fleet in the National Fishing Ground (ICES areas VIIIc and IXa). In this model, the Southern hake (Merluccius merluccius) represents the predator, and the blue whiting (Micromesistius poutassou)...
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this work, in particular, the introduction of the
growth functions in the preceding bioeconomic model
The objective of this study is to investigate the sustainability properties of the stock of the shrimp trawl
fishery in the Tonkin Gulf, Vietnam. Surplus production models of Verhulst-Schaefer and Gompertz-Fox
are applied to the shrimp trawl fishery, which is a typical tropical fishery with the characteristic properties
of small...
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Slide 1
Bioeconomic analysis of the artisanal shrimp
trawl
The objective of this study is to investigate the sustainability properties of the stock of the shrimp trawl
fishery in the Tonkin Gulf, Vietnam. Surplus production models of Verhulst-Schaefer and Gompertz-Fox
are applied to the shrimp trawl fishery, which is a typical tropical fishery with the characteristic properties
of small...
Full Text:
1
BIOECONOMIC ANALYSIS OF THE ARTISANAL SHRIMP TRAWL FISHERY IN THE
TONKIN GULF, VIETNAM
Gear technologists have, in recent years, developed rigid sorting grids, Sort-X, in bottom trawls, to improve the size selectivity of this type of gear. Experiments with the Sort-X system in the aft sections of trawls were carried out aboard Norwegian and Russian trawlers along the coast of Northern Norway and...
This paper shows that the importance of fish habitat depends in part on the management of the fishery. Two cases of cold water coral - fisheries interactions are studied in a bioeconomic model setting: Norwegian and Icelandic redfish fisheries. The two countries have applied different types of management; Norway’s management...
We introduce a modified version of the standard Gordon-Schaefer fishery model. Standard theoretical models usually treat fishing effort as an aggregate measure encompassing all different types of inputs. Consequently, these models do not enable us to examine the problem of fleet redundancy and capital stuffing separately, i.e. two ways in...
Human-induced changes in life-history traits have been observed for many harvested populations, with a component of those changes being attributed to an evolutionary (i.e., genetic) response. Most notably, fish stocks that experience high fishing mortality show a tendency to mature earlier and at a smaller size. Some have suggested that...
The objectives pursued by governments managing fisheries may include harvesting the fish stocks to maximize profits, to minimize the impact of harvesting on the marine ecosystem, or to secure jobs in the fishing industry. These objectives all depend on the composition of the fishing fleet as the various vessel types...
The sustainable management of small-scale fisheries in coral reef ecosystems constitutes a difficult objective especially because these fisheries usually face several stringent pressures including demographic growth and climate changes. The implications are crucial in term of food security as fish represents the major protein source for local populations in those...
Over the past 30 years, fisheries management on the west coast of the United States has undergone a rapid evolution. Starting with very limited management and stock assessment techniques, the complexity of fishery models and size and breadth of fishery data sets have gradually increased, which has coincided with increasingly...
Globally, alterations of marine food webs due to overfishing of species at high trophic levels are leading to unpredictable changes in coastal ecosystems. In parts of the Western Indian Ocean, increasing abundances of sea urchins (particularly Tripneustes gratilla) have been observed. Sea urchins’ grazing intensity on seagrass beds is generally...
The West Coast Rock Lobster fishery is Australia's most valuable commercial fishery. Around 550 vessels
harvest 10,500 tonnes of lobster per annum. The industry has an enviable track record of biological
management which has been based on a variety of input controls. In recent years this has necessitated three
significant...
Fishery scientists distinguish between recruitment overfishing (i.e. suboptimally low reproduction because the spawning stock is fished down) and growth overfishing (i.e. catching fish at an inefficiently young age). We use an age-structured bio-economic model to study how important the (endogenous) recruitment is compared to the growth of individual fish under...
This paper reviews New Zealand‚ orange roughly fishery management and applies a bioeconomic model to explain the seamount depletion externality by bottom trawling. The model shows that despite an upper limit on annual harvest, the potential gains in economic rent from trawling on pristine habitat, where catch rates are high,...
Acknowledging that there is stochasticity in the dynamics of a fish stock, one has a situation where the fish stock can collapse even without any fishing pressure. To derive the probability of collapse, we suggest a Monte Carlo approach because it is relatively simple model and can capture complex stock...
Cameroon is a country of Central Africa, with 402 km coastline where occur intense industrial and small scale marine, multispecies/gears fishing activities. Fishing accounts for 5.2% of GDP in the primary sector and 1.7% of GDP. The Ministry of Livestock’s, Fisheries and Animal Industries is responsible of the fisheries policy...
Motivated by the evidence that many collapsed stocks have failed to recover despite fishing mortality has been reduced, or even when a moratorium is currently in effect, we develop a spline methodological approach to analyze the stochastic population dynamics of fish stocks at low stock levels. The aim of this...
The sustainable management of small-scale fisheries
in coral reef ecosystems constitutes a difficult objective
especially because these fisheries usually face several stringent pressures including demographic growth and climate
changes. The implications are crucial in term of food security as fish represents the major protein source for local
populations in those...
The objective of this study is to investigate the sustainability properties of the stock of the shrimp trawl
fishery in the Tonkin Gulf, Vietnam. Surplus production models of Verhulst-Schaefer and Gompertz-Fox
are applied to the shrimp trawl fishery, which is a typical tropical fishery with the characteristic properties
of small...
With the development of the ecosystem approach to f
isheries (EAF), fisheries management is
increasingly required to deal with multiple, often
conflicting objectives. In this context, the
stochastic co-viability approach has been proposed
as a useful modeling framework as it allows
for the combined representation of complex fisherie
s dynamics,...
This paper presents a new bio-economic simulation model for the Italian fisheries developed as a part of a project financed by The General Directorate for Fisheries and Aquaculture (under the Italian Ministry of Forestry and Agriculture Policies). The main objective of the model is to measure the effects of different...
The objective of this paper is to study the economic management of Eastern
Baltic cod (Gadusmorhua) under the influence of nutrient enrichment. Average
nitrogen concentration in the spawning areas during the spawning season of
cod stock is chosen to be an indicator of nutrient enrichment. The optimal cod
stock is...
The management of the French shellfish industry has been based for a century and a half on a Territorial Use Right in Fisheries (TURF) scheme. This was meant to ensure control over access and use and was seen as a potential remedy for overexploitation. But the resource, i.e. shellfish nutrients,...
Major fishery investment has recently been implemented in West Africa as part of the World Bank's West Africa Regional Fisheries Program. To support this effort the New Partnership for Africa's Development funded development of a Seafood Bio-Economic Assessment Model. The model was initially developed for Ghana, but will accommodate other...
In the Baltic Sea, the successful conservation of grey seals has increased seal-induced damages to the Atlantic salmon fishery. The paper addresses the conflict between the conservation of the formerly endangered species and professional fishermen whose livelihood is also regulated by fisheries management. We develop a bioeconomic model that accounts...
The World Summit on Sustainable Development (Johannesburg, 2002)
encouraged the application of the ecosystem approach by 2010.
We propose a framework that deals jointly with i) ecosystem dynamics,
ii) conflicting issues of production and preservation and
iii) robustness with respect to dynamics uncertainties.
More specifically, we define robust viability kernels...
The aim of this work is to develop a predator-prey model for two species of commercial importance captured by the Spanish fishing fleet in the National Fishing Ground (ICES areas VIIIc and IXa). In this model, the Southern hake (Merluccius merluccius) represents the predator, and the blue whiting (Micromesistius poutassou)...
We assess cod, herring, and sprat fisheries in the Baltic Sea under different salinity conditions using a bioeconomic model with simple predation functions. We compare the current fishing policy to an optimal policy under two different salinity conditions, which have a link to climate change. The fishery of these species...
We previously developed a spatially explicit, individual-based model (IBM) evaluating the bio-economic efficiency of fishing vessel movements between regions according to the catching and targeting of different species based on the most recent high resolution spatial fishery data. The main purpose was to test the effects of alternative fishing effort...
Fisheries affect fish stocks through their exploitation rate and exploitation pattern. Both influence the economic yield from the fish stock. In regulated fisheries, the exploitation rate is determined either by the acceptable level of fishing effort or catch, whereas the exploitation pattern is determined by selectivity of gears and/or regulatory...
In many estuarine and ocean areas, aquaculture is seen as an alternative to traditional commercial fish harvesting practices. A significant problem hindering the emergence or the continuing growth of aquaculture in many areas is the conflict that arises among it and other competing ocean uses. Real world examples include the...
This paper presents an empirical model of Georges Bank transboundary groundfish fishery, and reports results of a dynamic bioeconomic simulation used to evaluate the consequences of alternative management strategies for the multispecies fishery. Since the distribution of the stocks of the principal groundfish resources involves substantial movement and migration across...
This paper contributes to the literature on economic efficiency, technical change, bioeconomic modeling, and renewable resource economics in general by introducing output-oriented Debreu-Farrell technical inefficiency and technical progress into normative static and dynamic bioeconomic models of a fishery and examines the economic and policy ramifications for the open-access Nash and...
This paper briefly describes the past development of the Bali Strait small pelagic fishery, and presents the impact of increasing fishing pressure and climatic variable on the quantity of catch. This paper then presents an estimate of its rent potential and the impact of increasing fishing pressure on rent at...
This paper deals with the control of an invasive species, void of market value, and acting as a space competitor for a native valuable harvested species. The paper presents a theoretical bioeconomic model describing the interacting dynamics of the two stocks. In the model, control variables are the levels of...
Recent reports of fishery collapse paint a gloomy picture of the ocean's future; perhaps 100% of fisheries from the world's large marine ecosystems (LMEs) will be collapsed in just 40 years. While poor fisheries governance is now widely regarded as the cause, bioeconomic theory and anecdotal evidence suggest that rights-based...
Over the past fifteen years, the market for bluefin tuna has evolved in an attempt to further enhance the economic value of bluefin tuna landings. Historically, the US East Coast has been a major supplier of high quality bluefin tuna to Japan, the primary market for sashimi grade tuna. To...
We develop a methodological approach using splines to analyze the deterministic population dynamics of fish stocks at low stock levels. Considering the aggregate Northern cod stock by way of illustration, we reject the hypothesis of strong compensation estimated by the conventional regression methods used by classic bioeconomic models.
In this paper, a three-country dynamic bio-economic model is presented and used to simulate catch levels, stock size and profit potential of alternative management strategies for the Norwegian spring-spawning herring fishery. Management of the herring fishery is complicated by the migratory behaviour of the species moving between coastal state zones...
This paper deals with the economic impact of an aquatic invasive alien species on a coastal shellfish
fishery. A slipper-limpet (Crepidula fornicata ) was accidentally imported some decades ago, has
established and is spreading in the bay of Saint-Brieuc (France). This exotic species is acting as a space
competitor for...
The Northern Prawn Fishery is one of the most valuable fisheries in Australia with a yearly estimated value of production of about $64mil. Nine prawn species are commercially harvested from the Northern Prawn Fishery with 80% of annual average catch represented by the banana prawn (Fenneropenaeus merguiensis) and the tiger...
A canvass of the resource economics literature of the last thirty years yields a limited number of applications of economic theory to the problems of recreational fishing. This neglect may be linked to the short shrift given to the control of recreational fisheries (relative to commercial fisheries) by fisheries managers...