scholarly journals The evaluation of two management strategies for the Gulf of Alaska walleye pollock fishery under climate change

2009 ◽  
Vol 66 (7) ◽  
pp. 1614-1632 ◽  
Author(s):  
Z. Teresa A’mar ◽  
André E. Punt ◽  
Martin W. Dorn
Keyword(s):  
Climate Change ◽  
Management Strategy ◽  
Management Strategies ◽  
Gulf Of Alaska ◽  
Walleye Pollock ◽  
Reference Level ◽  
Climate Indices ◽  
Management Performance ◽  
Intergovernmental Panel ◽  
Alternative Management

Abstract A’mar, Z. T., Punt, A. E., and Dorn, M. W. 2009. The evaluation of two management strategies for the Gulf of Alaska walleye pollock fishery under climate change. – ICES Journal of Marine Science, 66: 1614–1632. Management strategy evaluation (MSE) is the process of using simulation testing with feedback to examine the robustness of candidate management strategies to error and uncertainty. The structure of the management strategy can be selected to attempt to satisfy desired (but conflicting) management objectives. MSE was used to assess the performance of the current management strategy and an alternative management strategy (the “dynamic B0” strategy) for the fishery for walleye pollock (Theragra chalcogramma) in the Gulf of Alaska (GOA), when age-1 recruitment was driven by climate. The relationships between age-1 abundance and climate indices (and the uncertainties associated with these relationships) were characterized within an age-structured operating model that was fitted to the data for GOA walleye pollock. Projections into the future were based on the fitted relationships and predictions of those indices from the Intergovernmental Panel on Climate Change (IPCC) models, using the current or the alternative management strategy to determine catch limits. Management performance (the ability to leave the stock close to the management reference level and achieve high and stable catches) deteriorated when age-1 recruitment was forced by climate, although stocks were kept near the reference level on average. In addition, the ability to estimate management-related quantities, such as spawning biomass, deteriorated markedly when recruitment was forced by climate. Performance was sensitive to the choice of IPCC dataset and, in particular, estimation and management performance was poorest (outcomes most variable) for the IPCC datasets that led to the greatest variation in recruitment to the fishery. Although basing management on a “dynamic B0” management strategy led to improved management and estimation performance, the magnitude of the improvement was slight.

The impact of regime shifts on the performance of management strategies for the Gulf of Alaska walleye pollock (Theragra chalcogramma) fishery

2009 ◽  
Vol 66 (12) ◽  
pp. 2222-2242 ◽  
Author(s):  
Z. Teresa A’mar ◽  
André E. Punt ◽  
Martin W. Dorn
Keyword(s):  
Management Strategy ◽  
Management Strategies ◽  
Sliding Window ◽  
Gulf Of Alaska ◽  
Walleye Pollock ◽  
Regime Shifts ◽  
Theragra Chalcogramma ◽  
Fishing Mortality ◽  
Walleye Pollock Theragra Chalcogramma ◽  
The Impact

Climate variability affects marine ecosystems. The mechanisms relating low-frequency environmental fluctuations (regime shifts) and their impacts on marine populations are not well established for most species, but there is an expectation that the accuracy of scientific advice provided to fisheries management would be improved if management strategies incorporated the effects of regime shifts on stocks. Management strategy evaluation is used to examine the impact of regime shifts in average recruitment on the performance of management strategies for the fishery for walleye pollock, Theragra chalcogramma , in the Gulf of Alaska. The current and four alternative management strategies are evaluated. The alternatives include management strategies with different definitions of the average recruitment used when calculating management reference points, e.g., a 25-year sliding-window method and a “dynamic B0” method. The current management strategy, which ignores the possibility of future regime shifts, kept the spawning biomass higher relative to the target level than the other management strategies and had the lowest risk of fishing mortality exceeding the overfishing limit. The sliding-window management strategy achieved the highest catches and the lowest interannual variation in catch, although at the cost of a higher risk of the fishing mortality exceeding the overfishing limit.

scholarly journals Challenges for the Integration of Water Resource and Drought-Risk Management in Spain

2019 ◽  
Vol 11 (2) ◽  
pp. 308 ◽  
Author(s):  
Jesús Vargas ◽  
Pilar Paneque
Keyword(s):  
Climate Change ◽  
Water Resources ◽  
Water Resource ◽  
Water Resources Management ◽  
Management Strategies ◽  
Drought Risk ◽  
Drought Management ◽  
Intergovernmental Panel ◽  
Resources Management ◽  
Increased Risk

Droughts are risks characterized by their complexity, uncertainty, and a series of other features, which differentiate them from other natural disasters and affect the strategies designed to manage them. These characteristics highlight the close relationship between drought management and water resources management. The following hypothesis is raised in this study—unsatisfactory integration of a drought-risk and water resources management strategies, increases the vulnerability to drought. To corroborate this hypothesis, the Spanish case was analyzed, where droughts are a recurrent phenomenon, due to the Mediterranean climate. Starting from the Intergovernmental Panel on Climate Change (IPCC) framework, which has been proposed to characterize vulnerability as a function of exposure, sensitivity, and adaptive capacity, this study analyzed the vulnerability in the Spanish River Basin Districts, through—(i) the integration of the predictable effects of climate change and the increased risk of exposure in hydrologic planning; (ii) the pressure on water resources that determines the sensitivity of the systems; and (iii) the development and implementation of drought management plans as a fundamental tool, in order to adapt before these events occur. The results showed that despite important advances in the process of conceiving and managing droughts, in Spain, there are still important gaps for an adequate integration of droughts risk into the water resource strategies. Therefore, despite the improvements, drought-risk vulnerability of the systems remained high.

scholarly journals Long term effect of climate change on rainfall in northwest Iraq

2014 ◽  
Vol 4 (3) ◽  
Author(s):  
Nadhir Al-Ansari ◽  
Mawada Abdellatif ◽  
Salahalddin Ali ◽  
Sven Knutsson
Keyword(s):  
Climate Change ◽  
Management Strategies ◽  
Daily Rainfall ◽  
Annual Rainfall ◽  
Water Shortages ◽  
Intergovernmental Panel ◽  
Continuous Decrease ◽  
Rainfall Trends ◽  
Semi Arid Region

AbstractMiddle East, like North Africa, is considered as arid to semi-arid region. Water shortages in this region, represents an extremely important factor in stability of the region and an integral element in its economic development and prosperity. Iraq was an exception due to presence of Tigris and Euphrates Rivers. After the 1970s the situation began to deteriorate due to continuous decrease in discharges of these rivers, are expected to dry by 2040 with the current climate change. In the present paper, long rainfall trends up to the year 2099 were studied in Sinjar area, northwest of Iraq, to give an idea about its future prospects. Two emission scenarios, used by the Intergovernmental Panel on Climate Change (A2 and B2), were employed to study the long term rainfall trends in northwestern Iraq. All seasons consistently project a drop in daily rainfall for all future periods with the summer season is expected to have more reduction compared to other seasons. Generally the average rainfall trend shows a continuous decrease. The overall average annual rainfall is slightly above 210 mm. In view of these results, prudent water management strategies have to be adopted to overcome or mitigate consequences of future severe water crisis.

scholarly journals Modelling the effects of climate change on shellfish production in marine artisanal fisheries of Ghana

2019 ◽  
Vol 2 ◽  
pp. 16 ◽  
Author(s):  
Sandra Akugpoka Atindana ◽  
Patrick Kwabena Ofori-Danson ◽  
Sandra Brucet
Keyword(s):  
Climate Change ◽  
Management Strategies ◽  
Sustainable Use ◽  
Predictor Variable ◽  
Primary Objective ◽  
Artisanal Fisheries ◽  
Climate Indices ◽  
Fish Catch ◽  
Decision Making Processes ◽  
Aquaculture Development

Background: Ghana’s marine artisanal fisheries, particularly the small pelagic fisheries, are in a state of crisis. The decline in the number of small pelagic fish are attributable to overfishing, climate variability and unsustainable fishing methods. Similarly, in the wake of climate change, shellfishes (particularly oysters, scallops and mussels) are highly vulnerable. Methods: A total of 55 years’ worth of data from Ghana’s marine artisanal fisheries were studied in relation to climate indices. The primary objective was to develop a simple linear regression model for predicting shellfish catch in Ghana. Key informant interviews were employed in soliciting data on changes in climate along the coastline and trends in marine artisanal shell fish catch.  Results: The predictor variable that significantly explained shellfish production was temperature. Hence, the model is a valuable tool to predict future trends in the shellfish catch in marine artisanal fisheries. Conclusions: Increases in sea surface temperature will adversely affect shellfish production. It is therefore important that the Ministry of Fisheries and Aquaculture Development and other stakeholders should, in their decision-making processes, ensure the formulation of climate smart policies and management strategies for sustainable use of the resource.

scholarly journals Evaluating management strategies for eastern Bering Sea walleye pollock (Theragra chalcogramma) in a changing environment

2011 ◽  
Vol 68 (6) ◽  
pp. 1297-1304 ◽  
Author(s):  
James N. Ianelli ◽  
Anne B. Hollowed ◽  
Alan C. Haynie ◽  
Franz J. Mueter ◽  
Nicholas A. Bond
Keyword(s):  
Climate Change ◽  
Bering Sea ◽  
Management Strategies ◽  
Walleye Pollock ◽  
Status Quo ◽  
Theragra Chalcogramma ◽  
Recruitment Pattern ◽  
Control Rules ◽  
Eastern Bering Sea ◽  
Walleye Pollock Theragra Chalcogramma

Abstract Ianelli, J. N., Hollowed, A. B., Haynie, A. C., Mueter, F. J., and Bond, N. A. 2011. Evaluating management strategies for eastern Bering Sea walleye pollock (Theragra chalcogramma) in a changing environment. – ICES Journal of Marine Science, 68: 1297–1304. The impacts of climate change on fish and fisheries is expected to increase the demand for more accurate stock projections and harvest strategies that are robust to shifting production regimes. To address these concerns, we evaluate the performance of fishery management control rules for eastern Bering Sea walleye pollock stock under climate change. We compared the status quo policy with six alternative management strategies under two types of recruitment pattern simulations: one that follows temperature-induced trends and the other that follows a stationary recruitment pattern similar to historical observations. A subset of 82 Intergovernmental Panel on Climate Change climate models provided temperature inputs from which an additional 100 stochastic simulated recruitments were generated to obtain the same overall recruitment variability as observed for the stationary recruitment simulations. Results indicate that status quo management with static reference points and current ecosystem considerations will result in much lower average catches and an increased likelihood of fishery closures, should reduced recruitment because of warming conditions hold. Alternative reference point calculations and control rules have similar performance under stationary recruitment relative to status quo, but may offer significant gains under the changing environmental conditions.

scholarly journals Simulation of selected management strategies on Canterbury sheep farms

1990 ◽  
pp. 211-215
Author(s):  
J.D. Finlayson ◽  
O.J. Cacho ◽  
A.C. Bywater
Keyword(s):  
Body Weight ◽  
Simulation Model ◽  
Management Strategy ◽  
Management Strategies ◽  
Model Management ◽  
Stocking Rate ◽  
Alternative Management ◽  
Sheep Farm ◽  
Gross Margins ◽  
Selection Of

A simulation model was used to investigate the effects of various combinations of stocking rate, drafting weight and lambing season on a hypothetical dryland farm in Canterbury. A selection of physical results is presented and financial impications of alternative management strategies are briefly discussed. Stocking rate and lambing time had considerable effects on animal performance, with minor effects from drafting weight. Gross margins were considerably affected by stocking rate; the highest return was obtained with conventional lambing at 15 su per ha and drafting lambs at 30 kg empty body weight. Keywords model, management strategy, sheep farm

scholarly journals Cost of Climate Change: Risk of Building Loss from Typhoon in South Korea

2020 ◽  
Vol 12 (17) ◽  
pp. 7107
Author(s):  
Ji-Myong Kim ◽  
Seunghyun Son ◽  
Sungho Lee ◽  
Kiyoung Son
Keyword(s):  
Climate Change ◽  
Business Models ◽  
Management Strategies ◽  
Extreme Rainfall ◽  
Intergovernmental Panel ◽  
Extreme Rainfall Events ◽  
Damage Scenarios ◽  
Global Mean Temperature ◽  
Building Loss ◽  
Typhoon Risk

In recent years, natural disasters and climate abnormalities have increased worldwide. The Fifth Assessment Report (2014) of the Intergovernmental Panel on Climate Change warned of extreme rainfall events, warming and acidification, global mean temperature rises, and average sea level rises. In many countries, changes in weather disaster patterns, such as typhoons and heavy rains, have already led to increased damage to buildings. However, the empirical quantification of typhoon risk and building damage due to climate change is insufficient. The purpose of this study was to quantify the risk of building loss from typhoon pattern change caused by climate change. To this end, the intensity and frequency of typhoons affecting Korea were analyzed to examine typhoon patterns. In addition, typhoon risk was quantified using the Korean typhoon vulnerability function utilized by insurers, reinsurers, and vendors, the major users of catastrophe modeling. Hence, through this study, it is possible to generate various risk management strategies, which can be used by governments when establishing climate change policies and help insurers to improve their business models through climate risk assessment based on reasonable quantitative typhoon damage scenarios.

scholarly journals Comprehensive Accounting for REDD+ Programs: A Pragmatic Approach as Exemplified in Guyana

Forests ◽  
2020 ◽  
Vol 11 (12) ◽  
pp. 1265 ◽  
Author(s):  
Katherine M. Goslee ◽  
Timothy R. H. Pearson ◽  
Blanca Bernal ◽  
Sophia L. Simon ◽  
Hansrajie Sukhdeo
Keyword(s):  
Climate Change ◽  
Anthropogenic Activities ◽  
Cost Effective ◽  
Forest Degradation ◽  
Simple Approach ◽  
Reference Level ◽  
Emission Sources ◽  
Pragmatic Approach ◽  
Intergovernmental Panel ◽  
Effective Manner

Completeness is an important element for Reducing Emissions from Deforestation and forest Degradation (REDD+) accounting to ensure transparency and accountability. However, including a full accounting for all emission sources in a REDD+ program is often resource-intensive and cost-prohibitive, especially considering that some emission sources comprise far less than 10% of total emissions and are thus considered insignificant according to Intergovernmental Panel on Climate Change (IPCC) guidance. This is evident in forest reference emission level (FREL)/forest reference level (FRL) submissions to the United Nations Framework Convention on Climate Change (UNFCCC). Of the 50 countries that have submitted FRELs to date, only half of them include degradation in their FRELs even though degradation is often a significant source of emissions. Half of the countries that do include degradation use satellite imagery without necessarily specifying degrading activities or separating anthropogenic activities. Guyana provides an example of an approach that enables inclusion of all emission sources while considering the significance of each when developing an accounting approach. Since submitting its FREL in 2014, Guyana has made stepwise improvements to its emission estimates so that the country is now able to report on all deforestation and degradation activities resulting in emissions, whether significant or not. Based on the example of Guyana’s efforts, the authors recommend a simple approach to move towards complete accounting in a cost-effective manner. This approach can be scaled to other countries with other activities that results in greenhouse gas emissions from deforestation and forest degradation. Such complete accounting allows for higher accountability in REDD+ systems and can lead to greater effectiveness in reducing emissions.

scholarly journals Optimal Management Strategies for Alfalfa Production Within a Total Farm Plan

1985 ◽  
Vol 17 (2) ◽  
pp. 127-138 ◽  
Author(s):  
David L. Debertin ◽  
Angelos Pagoulatos
Keyword(s):  
Linear Programming ◽  
Management Strategy ◽  
Programming Model ◽  
Management Strategies ◽  
Linear Programming Model ◽  
Optimal Management ◽  
Alternative Management ◽  
Grain Crops ◽  
Net Returns

AbstractThis paper examines the impacts of alternative management strategies for the production of alfalfa within the context of a total farm plan. A linear programming model is used to represent a 600-acre farm which can grow either grain crops or alfalfa. Alfalfa production competes with the grain crops for available land, labor, machinery, and field time over a calendar of tillage, planting, cutting, spraying, and harvesting activities. The profitability of an acre of alfalfa and the contribution of alfalfa to net returns for the farm varies quite widely depending on the particular alfalfa management strategy selected.

Sign in / Sign up

Export Citation Format

Share Document