Management strategies for spasmodic stocks: a Canadian Atlantic redfish fishery case study

2020 ◽  
Vol 77 (4) ◽  
pp. 684-702
Author(s):  
Roberto Licandeo ◽  
Daniel E. Duplisea ◽  
Caroline Senay ◽  
Julie R. Marentette ◽  
Murdoch K. McAllister
Keyword(s):  
Inventory Management ◽  
Management Strategy ◽  
Management Strategies ◽  
Trawl Survey ◽  
Eastern Canada ◽  
Strategy Evaluation ◽  
Management Procedures ◽  
Harvest Control Rule ◽  
Sebastes Mentella

There exist few recommendations for managing stocks with spasmodic recruitment, despite such stocks being not uncommon. Management procedures (MPs), developed for two species of redfish (Sebastes mentella and Sebastes fasciatus) in eastern Canada, are recommended for setting catch limits during periods of high and low abundance. A well-designed fishery-independent trawl survey is essential to provide advance warning of strong recruitment events and project future recruitment. Under an “inventory management” strategy, a more appropriate aim in spasmodic stocks may be to maximize the number of years with “good catches,” instead of maximizing total catches, as is traditionally considered in management strategy evaluation (MSE). Following a spasmodic recruitment event, an empirical harvest control rule based on larger fish delays the harvest of large cohorts by a few years, targets more commercially valuable fish sizes, and reduces the risk of growth overfishing. Capped MPs produced longer periods of large catches than uncapped MPs. MPs allowed for low harvests during periods of low abundance, thus avoiding unnecessary hardship in the industry. MPs evaluated here could be good candidates for other stocks with similar or less extreme recruitment variability.

LIFE-OF-PROJECT ENVIRONMENTAL MANAGEMENT STRATEGY: CASE STUDY OF THE CONFEDERATION BRIDGE PROJECT, CANADA

1999 ◽  
Vol 01 (04) ◽  
pp. 429-439 ◽  
Author(s):  
JEFFREY L. BARNES ◽  
DAVID LEMON
Keyword(s):  
Environmental Management ◽  
Management Strategy ◽  
Management Strategies ◽  
Management Plan ◽  
Project Planning ◽  
Public Project ◽  
Eastern Canada ◽  
Environmental Management Strategies ◽  
Infrastructure Project

The developer of the Confederation Bridge Project in eastern Canada is successfully implementing a life-of-project environmental management strategy for this privately-funded public project. The cornerstone of this strategy is the Environmental Management Plan (EMP), an umbrella document which describes how the developer is managing all environmental aspects of the project throughout the construction phase and the subsequent 35-year period of private ownership. The EMP is comprised of several dynamic plans and programmes. Owing to unique circumstances, the EMP was developed prior to the completion of the environmental assessment, providing an example of the benefit of such, especially for a finance-build-own-operate-transfer infrastructure project. The experience of this project leads to the conclusion that the use of environmental management systems to encapsulate environmental management strategies early in project planning would be beneficial.

Using management strategy evaluation to establish indicators of changing fisheries

2019 ◽  
Vol 76 (9) ◽  
pp. 1653-1668 ◽  
Author(s):  
T.R. Carruthers ◽  
A.R. Hordyk
Keyword(s):  
Management Strategy ◽  
Statistical Power ◽  
Stock Assessment ◽  
Model Misspecification ◽  
Management Approach ◽  
Data Types ◽  
Quality Of Data ◽  
Management Strategy Evaluation ◽  
Strategy Evaluation ◽  
Management Procedures

A new indicator is described that uses multivariate posterior predictive data arising from management strategy evaluation (MSE) to detect operating model misspecification (exceptional circumstances) due to changing system dynamics. The statistical power of the indicator was calculated for five case studies for which fishery stock assessments have estimated changes in recruitment, natural mortality rate, growth, fishing efficiency, and size selectivity. The importance of the component data types that inform the indicator was also calculated. The indicator was tested for multiple types of management procedures (e.g., catch limits by stock assessment, size limits, spatial closures) given varying qualities of data. The statistical power of the indicator could be high even over short time periods and depended on the type of system change and quality of data. Statistical power depended strongly on the type of management approach, suggesting that indicators should be established that rigorously account for feedbacks between proposed management and observed data. MSE processes should use alternative operating models to evaluate protocols for exceptional circumstances to ensure they are of acceptable statistical power.

scholarly journals Designing tools to evaluate fishery management strategies: can the scientific community deliver?

2007 ◽  
Vol 64 (6) ◽  
pp. 1077-1084 ◽  
Author(s):  
Jon T. Schnute ◽  
Mark N. Maunder ◽  
James N. Ianelli
Keyword(s):  
Programming Languages ◽  
Scientific Community ◽  
Fishery Management ◽  
Stock Assessment ◽  
Management Strategies ◽  
Academic Disciplines ◽  
Strategy Evaluation ◽  
Management Procedures ◽  
Human Skills ◽  
Testing Management

Abstract Schnute, J. T., Maunder, M. N., and Ianelli, J. N. 2007. Designing tools to evaluate fishery management strategies: can the scientific community deliver? – ICES Journal of Marine Science, 64: 1077–1084. Techniques for quantitative fishery management have evolved rapidly during a period when computers, programming languages, and computational algorithms have also changed dramatically. Despite these advances, many stock assessment methods remain untested. A process of management strategy evaluation (MSE) could potentially rectify this problem, but it would require a framework in which to conduct systematic tests. We survey the tools currently used for stock assessments and discuss the development of new standards for testing management procedures. A successful project would depend on human skills scattered among various nations, organizations, and academic disciplines. Analogies from civil engineering illustrate the discipline and collaboration required for an effective outcome. If the world community of fishery scientists could design, build, and support such a project, it would revolutionize the theory, teaching, and practice of scientific fishery management.

Towards a balanced presentation and objective interpretation of acoustic and trawl survey data, with specific reference to the eastern Scotian Shelf

2016 ◽  
Vol 73 (12) ◽  
pp. 1914-1921 ◽  
Author(s):  
J. Michael Jech ◽  
Ian H. McQuinn
Keyword(s):  
Atlantic Cod ◽  
Management Strategies ◽  
Pelagic Fish ◽  
Trophic Levels ◽  
Fish Abundance ◽  
Forage Fish ◽  
Specific Reference ◽  
Trawl Survey ◽  
Scotian Shelf ◽  
Eastern Canada

A debate has developed over the ecosystem consequences following the collapse of Atlantic cod throughout the coastal waters of eastern Canada. The explosive increase in pelagic fish abundance in scientific bottom-trawl catches on the eastern Scotian Shelf has been interpreted as being due to either (i) a “pelagic outburst” of forage fish abundance resulting from predator release or conversely (ii) a change in pelagic fish vertical distribution leading to a “suprabenthic habitat occupation” thereby increasing their availability to bottom trawls. These two interpretations have diametrically opposing ecological consequences and suggest different management strategies for these important forage fish species. We argue that an objective evaluation of the available evidence supports the hypothesis that the abundance of forage fish has not increased in response to the demise of cod and other top predators, and the reliance on a single sampling gear with low catchability has biased and will continue to bias the interpretation of demographic trends of pelagic fish populations. We advocate that multiple sampling technologies providing alternative perspectives are needed for the monitoring and management of the various trophic levels if we are to achieve a balanced and objective understanding of marine ecosystems.

Challenges of management strategy evaluation for small pelagic fish: the Bay of Biscay anchovy case study

2019 ◽  
Vol 617-618 ◽  
pp. 245-263 ◽  
Author(s):  
S Sánchez ◽  
L Ibaibarriaga ◽  
A Uriarte ◽  
R Prellezo ◽  
M Andrés ◽  
...  
Keyword(s):  
Management Strategy ◽  
Pelagic Fish ◽  
Bay Of Biscay ◽  
Small Pelagic Fish ◽  
Management Strategy Evaluation ◽  
Strategy Evaluation

A management strategy evaluation of the commercial sockeye salmon fishery in Bristol Bay, Alaska

2019 ◽  
Vol 76 (9) ◽  
pp. 1669-1683 ◽  
Author(s):  
Curry J. Cunningham ◽  
Christopher M. Anderson ◽  
Jocelyn Yun-Ling Wang ◽  
Michael Link ◽  
Ray Hilborn
Keyword(s):  
Management Strategy ◽  
Sockeye Salmon ◽  
Estimation Error ◽  
Management Strategies ◽  
Fishing Effort ◽  
Time Varying ◽  
Bristol Bay ◽  
Traditional Methods ◽  
Management Strategy Evaluation ◽  
Strategy Evaluation

Bristol Bay, Alaska, is home to the largest sockeye salmon (Oncorhynchus nerka) fishery in the world, harvesting an average of 25 million fish with an ex-vessel value exceeding US$100 million annually. Daily fishing effort is adaptively managed to achieve stock-specific escapement goals. Traditional methods for defining these goals relied on stock–recruitment analysis; however, this approach often ignores three fundamental sources of uncertainty: estimation error, implementation uncertainty, and time-varying recruitment dynamics. To compare escapement goal alternatives, we conducted a management strategy evaluation that simulated time-varying recruitment across production regimes and replicated the daily in-season management process. Results indicate (i) implementation uncertainty can be reasonably approximated with simple rules reflecting fishery managers’ daily decision process; (ii) despite implementation uncertainty, escapement goals are likely to be realized or exceeded, on average; and (iii) management strategies targeting escapement levels estimated by traditional methods to produce maximum sustainable yield may result in lower catch and greater variability in fishing opportunity compared with a strategy with defining high and low escapement goals that are targeted depending on assessed run size, which may maximize future catch while reducing the frequency of extremely low harvests.

scholarly journals Simulation-based management strategy evaluation: ignorance disguised as mathematics?

2009 ◽  
Vol 66 (4) ◽  
pp. 754-762 ◽  
Author(s):  
Marie-Joëlle Rochet ◽  
Jake C. Rice
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Simulations ◽  
Management Strategy ◽  
Management Strategies ◽  
Stochastic Modelling ◽  
Alternative Methods ◽  
Risk Level ◽  
Management Strategy Evaluation ◽  
Strategy Evaluation ◽  
Simulation Based

Abstract Rochet, M-J. and Rice, J. C. 2009. Simulation-based management strategy evaluation: ignorance disguised as mathematics? – ICES Journal of Marine Science, 66: 754–762. Simulation-based management strategy evaluations are increasingly developed and used for science advice in support of fisheries management, along with risk evaluation and decision analysis. These methods tackle the problem of uncertainty in fisheries systems and data by modelling uncertainty in two ways. For quantities that are difficult to measure accurately or are inherently variable, variables are replaced by probability distributions, and system dynamics are simulated by Monte Carlo simulations, drawing numbers from these distributions. For processes that are not fully understood, arrays of model formulations that might underlie the observed patterns are developed, each is assumed successively, and the results of the corresponding arrays of model results are then combined. We argue that these approaches have several paradoxical features. Stochastic modelling of uncertainty is paradoxical, because it implies knowing more than deterministic approaches: to know the distribution of a quantity requires more information than only estimating its expected value. To combine the results of Monte Carlo simulations with different model formulations may be paradoxical if outcomes of concern are unlikely under some formulations but very likely under others, whereas the reported uncertainty from combined results may produce a risk level that does not occur under any plausible assumed formulation. Moreover, risk estimates of the probability of undesirable outcomes are often statements about likelihood of events that were seldom observed and lie in the tails of the simulated distributions, where the results of Monte Carlo simulation are the least reliable. These potential paradoxes lead us to suggest that greater attention be given to alternative methods to evaluate risks or management strategies, such as qualitative methods and empirical post hoc analyses.

scholarly journals Fisheries management for regime-based ecosystems: a management strategy evaluation for the snow crab fishery in the eastern Bering Sea

2012 ◽  
Vol 70 (5) ◽  
pp. 955-967 ◽  
Author(s):  
Cody S. Szuwalski ◽  
André E. Punt
Keyword(s):  
Fisheries Management ◽  
Bering Sea ◽  
Management Strategy ◽  
Management Strategies ◽  
Regime Shifts ◽  
Snow Crab ◽  
Management Strategy Evaluation ◽  
Eastern Bering Sea ◽  
Strategy Evaluation ◽  
Spawning Biomass

Abstract Szuwalski, C., and Punt A. E. 2013. Fisheries management for regime-based ecosystems: a management strategy evaluation for the snow crab fishery in the eastern Bering Sea. – ICES Journal of Marine Science, 70: 955–967. Regime shifts are a prominent feature of the physical environment of some ecosystems and have the potential to influence stock productivity. However, few management strategies or harvest control rules (HCRs) consider the possibility of changes in stock productivity. A management strategy evaluation is conducted for the snow crab (Chionoecetes opilio) fishery in the eastern Bering Sea, an ecosystem influenced by regime shifts. Operating models that project recruitment as a single average (i.e. the current basis for management advice), regime-based with no relationship between recruitment and spawning biomass, and regime-based with control of recruitment oscillating between environmental conditions and spawning biomass are considered. An HCR that accounts for shifts in recruitment regime is compared with the status quo HCR for each operating model. The regime-based HCR increases yield and decreases variability in yield at the cost of a higher probability of overfishing in regime-based systems. However, the regime-based HCR slightly decreases yield (no change in variability) and increases the probability of overfishing in non-regime-based systems. Identifying changes in productivity that are definitely driven by environmental regime rather than fishing pressure is the largest difficulty in implementing these rules.

scholarly journals Inventory Management in SMEs Operating in Polish Group Purchasing Organizations during the COVID-19 Pandemic

Risks ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 63
Author(s):  
Grzegorz Zimon ◽  
Vitalina Babenko ◽  
Beata Sadowska ◽  
Katarzyna Chudy-Laskowska ◽  
Blanka Gosik
Keyword(s):  
Inventory Management ◽  
Management Strategy ◽  
Management Strategies ◽  
Financial Security ◽  
Doing Business ◽  
The World ◽  
Conservative Policy ◽  
Group Purchasing Organizations ◽  
Supply Systems ◽  
Research Period

The COVID-19 virus has hit the economy around the world. In Poland, SMEs have the greatest problems with doing business. Border blockades and the quarantine for enterprises in virtually all industries throughout Poland greatly complicated the supply systems and the inventory management process. Up to now, SMEs have acted in group purchasing organizations to improve their competitive position. This form of activity also positively affects their financial security. Therefore, in this paper, the inventory management among this group of companies during the COVID-19 pandemic was analyzed. The purpose of the paper was to show how inventory management strategies changed during the COVID-19 pandemic in SMEs operating in industry GPOs. The analysis was carried out on a group of 88 Polish commercial enterprises operating in purchasing groups. The research period covered the years 2017–2019 and March–June 2020. The research showed a change in inventory management strategy in SMEs during the pandemic time of COVID-19. For the first four months, managers of enterprises tried to pursue a conservative policy and to accumulate stocks in the event of a shortage of supplies. This article also presents the form of security that was applied for SMEs operating in group purchasing organizations (GPOs) to avoid forced downtime caused by the COVID-19 pandemic.

scholarly journals The effect of marine closures on a feedback control management strategy used in a spatially aggregated stock assessment: a case study based on pink ling in Australia

2017 ◽  
Vol 74 (11) ◽  
pp. 1960-1973 ◽  
Author(s):  
André E. Punt ◽  
Malcolm Haddon ◽  
L. Richard Little ◽  
Geoffrey N. Tuck
Keyword(s):  
Feedback Control ◽  
Reference Point ◽  
Management Strategy ◽  
Stock Assessment ◽  
Management Strategies ◽  
Target Level ◽  
Operating Model ◽  
Stock Size ◽  
Control Management

Simulation is used to explore the effect of spatial heterogeneity and spatial closures on the ability of feedback-control management strategies to achieve goals relating to conservation and utilization of fishery resources. The operating model underlying the projections is based on pink ling, Genypterus blacodes, off southern Australia and assumes that animals are sedentary following settlement. The management strategies are able to move the resource towards the target level in the absence of spatial closures even though assessment results are biased. The probability of reducing the stock below its limit reference point is higher when growth rates vary spatially, but the effect is small. The probability of the stock being above its target reference point is lower when one of the smaller spatial areas is closed. However, performance is markedly different when a larger fraction of the total area is closed, with stock size being substantially larger than the target at the end of the projection period.

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