scholarly journals Reference points and management strategies: lessons from quantum mechanics

2006 ◽  
Vol 63 (1) ◽  
pp. 4-11 ◽  
Author(s):  
Jon T. Schnute ◽  
Rowan Haigh
Keyword(s):  
Quantum Mechanics ◽  
Management Strategies ◽  
Practical Importance ◽  
Reference Points ◽  
Surplus Production ◽  
Management Algorithm ◽  
Production Models ◽  
Conceptual Role ◽  
Common Framework ◽  
Mathematical Algorithms

Abstract Fisheries management often relies heavily on precautionary reference points estimated from complex statistical models. An alternative approach uses management strategies defined by mathematical algorithms that calculate controls, like catch quotas, directly from the observed data. We combine these two distinct paradigms into a common framework using arguments from the historical development of quantum mechanics. In fisheries, as in physics, the core of the argument lies in the technical details. We illustrate the process of designing a management algorithm similar to one actually used by the International Whaling Commission. Reference points and surplus production models play a conceptual role in defining management strategies, even if marine populations do not obey such simplistic rules. Physicists have encountered similar problems in formulating quantum theory, where mathematical objects with seemingly unrealistic properties generate results of great practical importance.

scholarly journals Fisheries Reference Point and Stock Status of Croaker Fishery (Sciaenidae) Exploited from the Bay of Bengal, Bangladesh

2022 ◽  
Vol 10 (1) ◽  
pp. 63
Author(s):  
Partho Protim Barman ◽  
Md. Mostafa Shamsuzzaman ◽  
Petra Schneider ◽  
Mohammad Mojibul Hoque Mozumder ◽  
Qun Liu
Keyword(s):  
Bay Of Bengal ◽  
Maximum Sustainable Yield ◽  
Reference Points ◽  
Production Model ◽  
Fishing Pressure ◽  
Surplus Production ◽  
Stock Status ◽  
Management Measures ◽  
Production Models ◽  
The Monte Carlo Method

This research evaluated fisheries reference points and stock status to assess the sustainability of the croaker fishery (Sciaenidae) from the Bay of Bengal (BoB), Bangladesh. Sixteen years (2001–2016) of catch-effort data were analyzed using two surplus production models (Schaefer and Fox), the Monte Carlo method (CMSY) and the Bayesian state-space Schaefer surplus production model (BSM) method. This research applies a Stock–Production Model Incorporating Covariates (ASPIC) software package to run the Schaefer and Fox model. The maximum sustainable yield (MSY) produced by all models ranged from 33,900 to 35,900 metric tons (mt), which is very close to last year’s catch (33,768 mt in 2016). The estimated B > BMSY and F < FMSY indicated the safe biomass and fishing status. The calculated F/FMSY was 0.89, 0.87, and 0.81, and B/BMSY was 1.05, 1.07, and 1.14 for Fox, Schaefer, and BSM, respectively, indicating the fully exploited status of croaker stock in the BoB, Bangladesh. The representation of the Kobe phase plot suggested that the exploitation of croaker stock started from the yellow (unsustainable) quadrant in 2001 and gradually moved to the green (sustainable) quadrant in 2016 because of the reduction in fishing efforts and safe fishing pressure after 2012. Thus, this research suggests that the current fishing pressure needs to be maintained so that the yearly catch does not exceed the MSY limit of croaker. Additionally, specific management measures should implement to guarantee croaker and other fisheries from the BoB.

scholarly journals Bayesian state-space models with multiple CPUE data: the case of a mullet fishery

2017 ◽  
Vol 81 (3) ◽  
pp. 361 ◽  
Author(s):  
Rodrigo Sant’Ana ◽  
Paul Gerhard Kinas ◽  
Laura Villwock de Miranda ◽  
Paulo Ricardo Schwingel ◽  
Jorge Pablo Castello ◽  
...  
Keyword(s):  
State Space ◽  
Stock Assessment ◽  
Reference Points ◽  
State Space Models ◽  
Southern Population ◽  
Catch Per Unit Effort ◽  
Bayesian Hierarchical ◽  
Surplus Production ◽  
Production Models ◽  
Borrowing Strength

We propose a novel Bayesian hierarchical structure of state-space surplus production models that accommodate multiple catch per unit effort (CPUE) data of various fisheries exploiting the same stock. The advantage of this approach in data-limited stock assessment is the possibility of borrowing strength among different data sources to estimate reference points useful for management decisions. The model is applied to thirteen years of data from seven fisheries of the lebranche mullet (Mugil liza) southern population, distributed along the southern and southeastern shelf regions of Brazil. The results indicate that this modelling strategy is useful and has room for extensions. There are reasons for concern about the sustainability of the mullet stock, although the wide posterior credibility intervals for key reference points preclude conclusive statistical evidence at this time

SUSTAINABLE DEVELOPMENT OF EUROPEAN HAKE RESOURCE: BIOECONOMIC PERSPECTIVE

2014 ◽  
Vol 22 (03) ◽  
pp. 353-375
Author(s):  
KUNAL CHAKRABORTY ◽  
MILON CHAKRABORTY ◽  
T. K. KAR
Keyword(s):  
Reference Points ◽  
Bioeconomic Model ◽  
Surplus Production ◽  
Biological Population ◽  
Maximum Profit ◽  
Production Models ◽  
Long Run ◽  
Steady State Solutions ◽  
Hake Fishery ◽  
European Hake

This paper deals with the surplus production models of Verhulst-Schaefer and Gompertz-Fox that are applied to the European Hake fishery to develop static as well as dynamic frameworks to investigate the sustainability properties of the stock, optimal utilization of the resource and the management of the fishery. To illustrate the approach through which long-run sustainability can achieve an optimum exploitation of the fishery, a conventional economic model is combined with a biological population growth model to develop a deterministic bioeconomic model. The parameters of the bioeconomic model are estimated using empirical data of catch and effort of the European Hake fishery. Standard reference points are analyzed and tax policies are introduced to attain the standard reference points. In order to achieve maximum profit from the fishery, optimal steady state solutions are determined for separate discount rates.

A Robust Method for Parameter Estimation from Catch and Effort Data

1989 ◽  
Vol 46 (1) ◽  
pp. 137-144 ◽  
Author(s):  
D. Ludwig ◽  
C. J. Walters
Keyword(s):  
Parameter Estimation ◽  
Robust Estimation ◽  
Robust Method ◽  
Amount Of Information ◽  
Surplus Production ◽  
Production Models ◽  
Composite Estimation ◽  
Estimation Scheme

The problem of robust estimation of optimal effort levels from surplus production models is considered. A variety of models are used to generate data, for the purpose of testing estimation schemes. The result of an estimation is an estimate of the optimal effort. These efforts are compared using the expected discounted value of a deterministic stock, which corresponds to the model used to generate the data. Such a criterion takes into account not only the loss due to bias in the estimated optimal effort, but also the loss due to the variance of the estimator. Estimation is difficult if there is a lack of informative variation in effort levels or stock sizes. In such cases, the estimation scheme which maximizes the criterion described above sacrifices realism in the representation of the stock-production relationship in order to reduce the variance of the estimate of optimal effort. We present a composite estimation scheme which performs acceptably in all the cases we have examined, and whose performance degrades slowly as the amount of information in the data decreases.

Surplus Production Models

2008 ◽  
pp. 105-126 ◽  
Author(s):  
Jon T. Schnute ◽  
Laura J. Richards
Keyword(s):  
Surplus Production ◽  
Production Models

scholarly journals Comment on “Impacts of historical warming on marine fisheries production”

Science ◽  
2019 ◽  
Vol 365 (6454) ◽  
pp. eaax5721 ◽  
Author(s):  
Cody Szuwalski
Keyword(s):  
Surface Temperature ◽  
Sea Surface Temperature ◽  
Maximum Sustainable Yield ◽  
Structured Data ◽  
Sea Surface ◽  
Sustainable Yield ◽  
Surplus Production ◽  
Production Models ◽  
Fitting Production ◽  
Age Structured

Free et al. (Reports, 1 March 2019, p. 979) linked sea surface temperature (SST) to surplus production and estimated a 4% decline in maximum sustainable yield (MSY) since 1930. Changes in MSY are expected when fitting production models to age-structured data, so attributing observed changes to SST is problematic. Analyses of recruitment (a metric of productivity in the same database) showed increases in global productivity.

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