scholarly journals Developing management procedures that are robust to uncertainty: lessons from the International Whaling Commission

2007 ◽  
Vol 64 (4) ◽  
pp. 603-612 ◽  
Author(s):  
André E. Punt ◽  
Greg P. Donovan
Keyword(s):  
Control Laws ◽  
International Whaling Commission ◽  
Management Objectives ◽  
Management Procedure ◽  
Data Collection And Analysis ◽  
Process Error ◽  
Management Procedures ◽  
Stock Assessments ◽  
Management Advice ◽  
Aboriginal Subsistence

Abstract Punt, A. E. and Donovan, G. P. 2007. Developing management procedures that are robust to uncertainty: lessons from the International Whaling Commission. – ICES Journal of Marine Science, 64: 603–612. Traditionally, fisheries management advice has been based on stock assessments that considered merely the “best” set of assumptions while uncertainty arising only from observation and process error was quantified, if considered at all. Unfortunately, uncertainty attributable to lack of understanding of the true underlying system and to ineffective implementation may dominate the sources of error that must be accounted for if management is to be successful. The management procedure approach is advocated as the appropriate way to develop management advice for renewable resources. This approach, pioneered by the International Whaling Commission (IWC) Scientific Committee, takes politically agreed management objectives and incorporates all scientific aspects of management including data collection and analysis, development of robust harvest control laws or effort regulations, and monitoring. A primary feature is that uncertainty (including that arising from sources conventionally ignored) is taken into account explicitly through population simulations for a variety of scenarios. The nature of the management procedures developed for commercial and aboriginal subsistence whaling and the processes by which they have been developed is highlighted. We also identify lessons that have been learned from two decades of IWC experience and suggest how these can be applied to other fishery situations.

scholarly journals Evaluation of multiple management objectives for Northeast Atlantic flatfish stocks: sustainability vs. stability of yield

2005 ◽  
Vol 62 (6) ◽  
pp. 1104-1117 ◽  
Author(s):  
L.T. Kell ◽  
M.A. Pastoors ◽  
R.D. Scott ◽  
M.T. Smith ◽  
F.A. Van Beek ◽  
...  
Keyword(s):  
Stock Assessment ◽  
Low Frequency ◽  
Reference Points ◽  
Time Lags ◽  
Fishing Mortality ◽  
Actual System ◽  
Management Objectives ◽  
Management Procedure ◽  
Management Procedures ◽  
Pseudo Data

Abstract This paper describes a simulation study that evaluated the ICES scientific advisory process used to recommend total allowable catches (TACs) for flatfish stocks. Particular emphasis is given to examining the effects on stock biomass, yield and stability of constraining interannual variation in TACs. A “management strategy evaluation” approach is used where an operating model is used to represent the underlying reality, and pseudo data are generated for use within a management procedure. The management procedure comprises a stock assessment that uses data to estimate parameters of interest and a decision rule to derive TAC recommendations for the following year. Bounds on TAC of between 20% and 40% have little effect on yields or stability, while a 10% bound on TAC can affect the ability to achieve management targets and result in low-frequency cycling in the stock. In the short term, performance is highly dependent on current stock status but bounds have less effect if the stock is close to equilibrium for a target fishing mortality (F). In addition, it was shown that current ICES biomass and fishing mortality reference points are not always consistent, and several are clearly inappropriate. Importantly, including realistic sources and levels of uncertainty can result in far from optimal management outcomes based on the current procedures. Results also conflicted with expert opinion, in suggesting that management based on a fixed F regime could result in relatively stable yields despite fluctuations in year-class strength and that the management feedback process itself is implicated in causing fluctuations in the system due to significant time-lags in this process. We therefore emphasize that providing more precise population estimates or developing harvest control rules alone will not necessarily help in achieving management objectives, rather management procedures that are robust to uncertainty and tuned to meet management objectives need to be developed. Operating models in these simulations were constrained to be based on existing ICES methods and perceptions of stock dynamics, but we recommend that, in future, operating models that represent the best available understanding of the actual system dynamics be used to evaluate models and rules considered for application.

Bayesian integrated survey-based assessments: an example applied to North Sea herring (Clupea harengus) survey data

2011 ◽  
Vol 68 (8) ◽  
pp. 1387-1407 ◽  
Author(s):  
Richard Hillary
Keyword(s):  
North Sea ◽  
Survival Probability ◽  
Assessment Method ◽  
Reference Points ◽  
Clupea Harengus ◽  
Natural Mortality ◽  
Mortality Trends ◽  
Management Procedure ◽  
Management Procedures ◽  
Stock Assessments

Stock assessments that use only fisheries independent data have been developed from a number of different standpoints over the last 15 years. While the ability of such stock assessments to avoid the use of potentially compromised or hard to interpret commercial data or making certain assumptions that are common to traditional assessments has been established, little has been made of their potential for detecting and estimating complex mortality trends over time or their potential utility in survey-based management procedures. Using North Sea herring ( Clupea harengus ) data as an example, a Bayesian survey-based assessment method that is able to estimate all the key population variables is detailed. However, survival probability, and not fishing mortality that is conditional on natural mortality, is the key parameter. Reversible jump Markov chain Monte Carlo routines were developed to explore the range of ages over which survival separates into year and age effects (a common assumption in many stock assessments). Post hoc estimates of natural mortality suggest that changes over years and ages may have occurred in relativity to historic levels. The derivation of reference points based on survival probability and surplus biomass production are detailed as proxies for more common F-based reference points. The potential role for the outputs of such assessments in a management procedure sense is discussed.

Lessons learned from data-limited evaluations of data-rich reef fish species in the Gulf of Mexico: implications for providing fisheries management advice for data-poor stocks

2019 ◽  
Vol 76 (9) ◽  
pp. 1624-1639 ◽  
Author(s):  
Skyler R. Sagarese ◽  
William J. Harford ◽  
John F. Walter ◽  
Meaghan D. Bryan ◽  
J. Jeffery Isely ◽  
...  
Keyword(s):  
Gulf Of Mexico ◽  
Reef Fish ◽  
Fish Species ◽  
Stock Assessment ◽  
Lessons Learned ◽  
Management Objectives ◽  
Trade Offs ◽  
Data Limitations ◽  
Management Procedures ◽  
Reef Fish Species

Specifying annual catch limits for artisanal fisheries, low economic value stocks, or bycatch species is problematic due to data limitations. Many empirical management procedures (MPs) have been developed that provide catch advice based on achieving a stable catch or a historical target (i.e., instead of maximum sustainable yield). However, a thorough comparison of derived yield streams between empirical MPs and stock assessment models has not been explored. We first evaluate trade-offs in conservation and yield metrics for data-limited approaches through management strategy evaluation (MSE) of seven data-rich reef fish species in the Gulf of Mexico. We then apply data-limited approaches for each species and compare how catch advice differs from current age-based assessment models. MSEs identified empirical MPs (e.g., using relative abundance) as a compromise between data requirements and the ability to consistently achieve management objectives (e.g., prevent overfishing). Catch advice differed greatly among data-limited approaches and current assessments, likely due to data inputs and assumptions. Adaptive MPs become clearly viable options that can achieve management objectives while incorporating auxiliary data beyond catch-only approaches.

scholarly journals Consideration of uncertainties in environmental science and management with examples from Pacific salmon

2015 ◽  
Author(s):  
Randall Peterman
Keyword(s):  
Quantitative Methods ◽  
Environmental Science ◽  
Pacific Salmon ◽  
Natural Populations ◽  
Observation Error ◽  
Imperfect Data ◽  
State Dependent ◽  
Strategy Evaluation ◽  
Management Procedure ◽  
Management Procedures

An informal review of the history of new quantitative methods in environmental science, including environmental risk assessment, shows about a 10- to 20-year lag in wide acceptance of such methods by management agencies. To reduce that lag time as innovative methods continue to emerge, environmental scientists will need to work much more intensively with communications specialists on better ways to explain risk analyses and decision-making strategies to non-technical decision makers and the public. Four key uncertainties make such communication difficult: (1) natural variability in both physical and biological processes, (2) imperfect data arising from observation error (i.e., measurement error), (3) incomplete understanding of an environmental system's structure and dynamics, and (4) outcome uncertainty (deviations between realized outcomes and management targets). These uncertainties create risks -- risks to natural populations as well as to people who use them. Examples of these four sources of uncertainty are presented here for Pacific salmon (Oncorhynchus spp.). One promising framework for explicitly taking such uncertainties into account was initially developed in the early 1990s by scientific advisors to the International Whaling Commission. They built stochastic models, which essentially were comprehensive formal decision analyses, to derive management procedures (i.e., sampling designs for collecting data, methods to analyze those data, and state-dependent harvest-control rules for use by managers) that were robust to all the uncertainties considered. This method of "Management Strategy Evaluation" or "Management Procedure Evaluation" is now considered the "gold standard" for conducting risk assessments and making risk-management decisions in marine fisheries.

scholarly journals Prosedur Pengelolaan Keuangan pada Dinas Pemuda, Olahraga, Kebudayaan dan Pariwisata Kabupaten Kapuas

2019 ◽  
Vol 3 (1) ◽  
pp. 1-11
Author(s):  
Vivi Pancasari Kusumawardani
Keyword(s):  
Financial Management ◽  
Youth Sports ◽  
Secondary Data ◽  
District Office ◽  
Sports Culture ◽  
Management Procedure ◽  
Analysis Technique ◽  
Management Procedures ◽  
Data Collection Technique ◽  
District Culture

This study aims to determine the procedure for managing financial statements at the Kapuas District Office of Youth, Sports, Culture and Tourism.The data used in this study are documentary data, while the data sources used are secondary data with data collection technique in the form of documentation technique, namely collecting written material in the form of data obtained from the Finance Department of the Department of Youth, Sports, Culture and Tourism Kapuas Year 2015 and 2016. Data analysis technique use qualitative analysis technique.The results showed that: (1) the Kapuas District Youth, Sports, Culture and Tourism Office had financial management procedures as a guideline governing the financial management process that covered all financial aspects managed by the Kapuas District Culture, Youth and Sports Service. (2) In the financial management procedure owned by the Department of Youth, Sports, Culture and Tourism of the Kapuas Regency, it has complied with government regulations stipulated in the Minister of Home Affairs Regulation Number 13 of 2006.

scholarly journals Development of an assessment tool for infrastructure asset management of urban drainage systems

2020 ◽  
Author(s):  
Meriem Igroufa ◽  
Abbas Benzerra ◽  
Abdelghani Seghir
Keyword(s):  
Asset Management ◽  
Second Phase ◽  
Urban Drainage ◽  
Measurement Scales ◽  
Drainage Systems ◽  
Weighted Sum Method ◽  
Management Procedure ◽  
Management Procedures ◽  
Urban Drainage Systems ◽  
Infrastructure Asset Management

Abstract The present paper deals with the improvement of infrastructure asset management of urban drainage systems (UDS). A numerical tool for assessing the existing management procedures is proposed. It is based on a participatory methodology for the construction of a set of performance indicators. This methodology consists of two phases. The first concerns the identification of priority objectives, criteria and indicators related to the management of the UDS infrastructure. The second phase concerns the assessment of the global performance for each identified objective. Performance measurement scales are first defined for all the elements of the proposed methodology. Then, the Fuzzy Analytical Hierarchy Process (FAHP) is used for the weighting stage, and the Weighted Sum Method is used for the aggregation of indicators and criteria. To illustrate this methodology, a case study concerning Bejaia City in northern Algeria was carried out. Two priority objectives are identified for this case, they are divided into 6 criteria and 31 indicators. The results of the application of the developed tool highlighted some weaknesses that need improvements in the actual management procedure applied by the local sanitation services.

Reducing the Disruptive Behavior of Junior High School Students: A Classroom Self-Management Procedure

1988 ◽  
Vol 13 (4) ◽  
pp. 231-239 ◽  
Author(s):  
Deborah J. Smith ◽  
K. Richard Young ◽  
Richard P. West ◽  
Daniel P. Morgan ◽  
Ginger Rhode
Keyword(s):  
High School Students ◽  
Junior High School ◽  
Junior High ◽  
Self Management ◽  
School Students ◽  
Behaviorally Disordered ◽  
Resource Room ◽  
Management Procedure ◽  
Study Results ◽  
Management Procedures

The effectiveness of self-management procedures in reducing the disruptive and off-task behaviors of students in a special education resource classroom was assessed. Four junior high-aged students, three of whom were classified as behaviorally disordered and one as learning disabled, participated in the study. Results indicated that self-evaluation procedures implemented in the resource room reduced students' off-task and disruptive behaviors. Data collected concurrently in students' regular education classes showed little or no generalization of treatment gains from the resource room. Recommendations are offered for facilitating the generalization of the self-management skills.

Feasible stock trajectories: a flexible and efficient sequential estimator for use in fisheries management procedures

2012 ◽  
Vol 69 (1) ◽  
pp. 161-177 ◽  
Author(s):  
Nokome Bentley ◽  
Adam D. Langley
Keyword(s):  
Fisheries Management ◽  
Probability Distributions ◽  
Sequential Estimation ◽  
Alternative Methods ◽  
Model Parameters ◽  
Computationally Efficient ◽  
Likelihood Functions ◽  
Management Procedure ◽  
Management Procedures ◽  
Stock Recruitment

We describe a sequential estimation approach designed to be used as part of a fisheries management procedure; it is computationally efficient and able to be applied to varying types, and extents, of data. The estimator maintains a pool of stock trajectories, each having a unique combination of model parameters (e.g., stock–recruitment steepness) sampled from prior probability distributions. Each year, for each trajectory, the values of variables (e.g., current biomass) are updated and tested against specified constraints. Constraints further determine the feasibility of the trajectories by defining likelihood functions for model variables, or combinations of variables, in particular years. Trajectories that fail to meet one or more of the constraints are discarded from the pool and replaced by new trajectories. Each year, stochastic forward projections of the trajectories in the pool are used to determine an optimal catch level. The flexibility and accuracy of the estimator is evaluated using the fishery for snapper, Pagrus auratus , off northern New Zealand as a case study. The sequential nature of the algorithm suggests alternative methods of presentation for understanding and explaining the fisheries estimation process. We provide recommendations for both the evaluation and operation of management procedures that employ the estimator.

scholarly journals Genetic analyses of ling (Molva molva) in the Northeast Atlantic reveal patterns relevant to stock assessments and management advice

2014 ◽  
Vol 72 (2) ◽  
pp. 635-641
Author(s):  
Enrique Blanco Gonzalez ◽  
Halvor Knutsen ◽  
Per Erik Jorde ◽  
Kevin Alan Glover ◽  
Odd Aksel Bergstad
Keyword(s):  
Dna Markers ◽  
Life Stages ◽  
Oceanic Circulation ◽  
Apparent Absence ◽  
Northeast Atlantic ◽  
Eastern Group ◽  
Stock Assessments ◽  
Microsatellite Dna Markers ◽  
Management Advice ◽  
And Migration

Abstract The ling, Molva molva, is a commercially exploited demersal gadid fish distributed throughout the Northeast Atlantic. Here, we provide the first study of population genetic structure by genotyping 6 geographically distinct samples with 11 microsatellite DNA markers. The results rejected the hypothesis of a single ling stock in the Northeast Atlantic, and rather suggested the existence of two or more groups, with the main grouping represented by a western (comprising Rockall and Iceland) and an eastern group (Faroe Bank, Norway). Significant genetic differences coincide with an expanse of deep water that probably limits connectivity facilitated by migration. Retention in gyres and directional oceanic circulation may also prevent drift and admixture during planktonic life stages. On the other hand, the apparent absence of genetic differentiation within the eastern part of the distribution range indicates gene flow, perhaps by larval drift and migration, over considerable distances. Our findings should contribute to improving stock assessments and monitoring and thus fisheries management advice for the ling.

scholarly journals Modeling Discards in Stock Assessments: Red Grouper Epinephelus morio in the U.S. Gulf of Mexico

Fishes ◽  
2021 ◽  
Vol 7 (1) ◽  
pp. 7
Author(s):  
Kyle W. Shertzer ◽  
Erik H. Williams ◽  
Skyler R. Sagarese
Keyword(s):  
Gulf Of Mexico ◽  
Stock Assessment ◽  
Time Varying ◽  
Discard Mortality ◽  
Stock Assessments ◽  
Epinephelus Morio ◽  
Red Grouper ◽  
Management Advice ◽  
The U.S

To be as accurate as possible, stock assessments should account for discard mortality in fisheries if it occurs. Three common approaches to modeling discards in assessments are to lump dead discards with landings, treat dead discards as their own fleet, or link them conversely with landings through use of a retention function. The first approach (lumping) implicitly assumes that the selectivity of landings applies also to discards. In many cases, that assumption is false, for example, if discards comprise smaller fish than do landings. The latter two approaches avoid the assumption by modeling discards explicitly with their own selectivity pattern. Here, we examine these approaches to modeling discards. Using a simulation study, we demonstrate that the two approaches to modeling discards explicitly can provide identical results under both static and time-varying conditions. Then, using a stock assessment case study of red grouper Epinephelus morio in the U.S. Gulf of Mexico, we demonstrate that in practice the approaches to modeling discards can provide different outcomes, with implications for the resultant management advice. We conclude by comparing and contrasting the different approaches, calling for more research to elucidate which approach is most suitable under various sources of error typically encountered in discard data.

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