After 1950 traditional herring fisheries were revolutionized by a new technique: sonar, power block, larger
nets and bigger boats. As a result all major herring stocks in the North East Atlantic Ocean collapsed. The
most dramatic decline was that of the Atlanto-Scandian stock between Iceland and Norway from millions
of...
Studies on compliance with fishing regulations have looked at fishery crimes for which the offender faces a one-period
decision problem of maximizing an expected utility. Moreover, the returns to the crimes are uncertain
because the offender may lose them if caught. This paper extends these models by considering a fishery...
This study investigates the adjustment process of labor in the fishing industry of the Spanish regions
(Autonomous Communities). The analysis is based on a dynamic model applied to a panel of the 10
coastal regions in Spain for the period covering 1965 to 2001. A translog labor demand equation is...
Key decision variables in aquaculture management are stocking level, feeding schedule, temperature
control and batch length. In many management problems with an infinite planning horizon, the aim is to
find the batch length which results in maximum return if the same batch length applies to all future
batches. This may...
Spatial patterns of summer streamflow in the Cascade Mountains of Oregon vary dramatically between the geologically distinct High and Western Cascade regions. A key control is the partitioning of water input between a fast-draining shallow subsurface flow network (Western Cascades) versus a slow-draining deeper groundwater system (High Cascades). These differences...
Fisheries models are generally built to assess the dynamics of a resource with a given fishing mortality
which level can be decided by some “decision maker” and/or which can be an observed process, e.g. times series proportional to some observed values of fishing effort. In these cases, the resource dynamics...
Surface transient storage (STS) and hyporheic transient storage (HTS) have
functional significance in stream ecology and hydrology. Both provide refugia for aquatic
communities and their longer mean residence times (compared to the main flow) increase
the potential for biogeochemical reactions that can improve water quality. As STS and
HTS have...
Surface transient storage (STS) and hyporheic transient storage (HTS) have
functional significance in stream ecology and hydrology. Both provide refugia for aquatic
communities and their longer mean residence times (compared to the main flow) increase
the potential for biogeochemical reactions that can improve water quality. As STS and
HTS have...
Surface transient storage (STS) and hyporheic transient storage (HTS) have
functional significance in stream ecology and hydrology. Both provide refugia for aquatic
communities and their longer mean residence times (compared to the main flow) increase
the potential for biogeochemical reactions that can improve water quality. As STS and
HTS have...
Surface transient storage (STS) and hyporheic transient storage (HTS) have
functional significance in stream ecology and hydrology. Both provide refugia for aquatic
communities and their longer mean residence times (compared to the main flow) increase
the potential for biogeochemical reactions that can improve water quality. As STS and
HTS have...
Surface transient storage (STS) and hyporheic transient storage (HTS) have
functional significance in stream ecology and hydrology. Both provide refugia for aquatic
communities and their longer mean residence times (compared to the main flow) increase
the potential for biogeochemical reactions that can improve water quality. As STS and
HTS have...
Stabilization of the Yaquina Bay shoreline along the northeastern edge of the Hatfield Marine Science Center (HMSC) campus became necessary to halt erosion that threatened both HMSC critical infrastructure (seawater storage tank) and public access to the HMSC Nature Trail. A Dynamic Revetment (gravel beach) was installed in November, 2011...
Unfortunately, most of the stocks are damaged by natural disasters or human activities and rebuilding the
stock are urgent requirements. Until now, in the stock management, some policies are commonly believed
to valid but have not been confirmed. A simulation model of the population dynamics incorporating
uncertainty has been already...
The objective of the paper is to briefly present a comparative analysis of trends in the characteristics of
selected European fleets, observed over the last fifteen years, as an introduction to three empirical studies
of the behavioural determinants of these trends. The analysis presented aims at (i) describing changes
observed...
Stabilization of the Yaquina Bay shoreline along the northeastern edge of the Hatfield Marine Science Center (HMSC) campus became necessary to halt erosion that threatened both HMSC critical infrastructure (seawater storage tank) and public access to the HMSC Nature Trail. A Dynamic Revetment (gravel beach) was installed in November, 2011...
The Hatfield Marine Science Center (HMSC) is an interagency campus in Newport, Oregon with
a mission of research, education and outreach in marine sciences through collaborative
partnerships. Located on a 49 acre site on Yaquina Bay, Oregon, it is adjacent to diverse
habitats, many of which are subject to action...
These four items document the 2010-2011 permitting process to stabilize the eastern edge of the Hatfield Marine Science Center property. During late 2006, erosion forced the closure of the HMSC public estuary trail. In March 2007, an erosion control project using a gravel beach or "dynamic revetment" resulted in the...
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using a gravel beach or
“dynamic revetment” as a solution that would best maintain the natural and
These four items document the 2010-2011 permitting process to stabilize the eastern edge of the Hatfield Marine Science Center property. During late 2006, erosion forced the closure of the HMSC public estuary trail. In March 2007, an erosion control project using a gravel beach or "dynamic revetment" resulted in the...
These four items document the 2010-2011 permitting process to stabilize the eastern edge of the Hatfield Marine Science Center property. During late 2006, erosion forced the closure of the HMSC public estuary trail. In March 2007, an erosion control project using a gravel beach or "dynamic revetment" resulted in the...
These four items document the 2010-2011 permitting process to stabilize the eastern edge of the Hatfield Marine Science Center property. During late 2006, erosion forced the closure of the HMSC public estuary trail. In March 2007, an erosion control project using a gravel beach or "dynamic revetment" resulted in the...
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contradiction posed by the requirement that the
Port of Newport install an identical dynamic revetment as
The arrival in the 1980s of cultured shrimp has induced large changes on the World shrimp market. In this new environment, the French Guyana fishery production now competes strongly with some of these farm-produced shrimp. Consequently, this fishery has experienced serious export problems during the last decade. This paper is...
Exports of fish products are important to diversify sources of income and achieve higher standards of living to fisher folk. This paper attempts to trace the strategic situation of export oriented seafood industry in Sri Lanka, focusing on how the international market dynamics have influenced the emergence and development of...
In this paper an extended version of the well-known Faustmann model is developed for solving the rotation problem in fish farming. Two particularly important aspects of the problem are emphasized: namely first, the possibilities for cycles in relative price relationships and second, the problem with limitations in release time for...
Considering the operational needs on fisheries management, this research was aimed for understanding the adjustment processes of small-scaled fishing gear dynamic by measuring and analysing the seasonal fishing gear dynamic including seasonal fishing pattern and fishing gear interaction. To understand the fishermen's adaptation of their fishing effort from any changes...
We study the combined effects of periodically varying carrying capacity and survival rates on the fish population in the ocean (sea). We introduce a new delay differential equation model with a control parameter which describes how fish are harvested.
We consider a predation function as the function of the delayed...
In many situation, fishing activity adversely impacts the state of the marine ecosystem, impacts which feed back to affect fish stocks. Some ecosystems appear to have multiple equilibria and exhibit hysteresis, whereby they can become stuck in low productivity states. We show how adding ecosystem dynamics to a classic fisheries...
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...
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.
The hilsa shad (Tenualosa ilisha) fishery is by far the largest single species fishery in Bangladesh. In this paper, a simple bio-economic year-class based model is developed to describe the fishery and examine its properties. With the help of this model, the optimum sustainable yield of the fishery is calculated...
Increasingly fishery managers are expected to take an ecosystem approach to fisheries management that accounts for the interrelationships of target species as well as non-target species and habitat. Fishery managers would benefit from coupled ecological-economic models that includes both the human and ecological aspects of the fishery and incorporates them...
The impact of recent severe droughts throughout the United States, the potential for climate change to intensify the frequency and severity of drought, and discussion about the future of government assistance in agriculture highlight the need for a transition from drought as ‘disaster’ to drought as ‘managed risk’. However, guidance...
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dynamic aspects of an irrigated row crop farm is developed and used to explore the
nature of optimal
The impact of recent severe droughts throughout the United States, the potential for climate change to intensify the frequency and severity of drought, and discussion about the future of government assistance in agriculture highlight the need for a transition from drought as ‘disaster’ to drought as ‘managed risk’. However, guidance...
The impact of recent severe droughts throughout the United States, the potential for climate change to intensify the frequency and severity of drought, and discussion about the future of government assistance in agriculture highlight the need for a transition from drought as ‘disaster’ to drought as ‘managed risk’. However, guidance...
The impact of recent severe droughts throughout the United States, the potential for climate change to intensify the frequency and severity of drought, and discussion about the future of government assistance in agriculture highlight the need for a transition from drought as ‘disaster’ to drought as ‘managed risk’. However, guidance...
The impact of recent severe droughts throughout the United States, the potential for climate change to intensify the frequency and severity of drought, and discussion about the future of government assistance in agriculture highlight the need for a transition from drought as ‘disaster’ to drought as ‘managed risk’. However, guidance...