Fisheries Management Models Research Articles

Genetic population structure of the Blackspot seabream (Pagellus bogaraveo): contribution of mtDNA control region to fisheries management

Marine fisheries management models have traditionally considered biological parameters and geopolitical boundaries. The result is the existence of fisheries management units that do not match genetic populations. However, this panorama is changing with the contribution of genetic and genomic data. Pagellus bogaraveo is a commercially important sparid in the northeast Atlantic, with three stock components being considered by ICES: the Celtic Sea and Bay of Biscay, Atlantic Iberian waters and the Azores. The northern stock collapsed (1975–1985) and is essential to characterize the genetic makeup of the species, particularly in the Iberian Peninsula, where it is managed as a single stock. The mitochondrial control region was used to screen the intraspecific diversity and population structure of individuals from six locations across the species range. The genetic diversity found is similar among sites, and there is differentiation between the Azores and the remaining locations.

Improving Fishery Management Models and Methods

In a dynamic, environment, the decision makers make use of many different resources where two or more can act as substitutes. At each decision moment in time, the market prices will be constant, and the relative prices of accessible resources will determine the economic rationale of the process. Ignoring or downplaying the effects of substitutability of resources in dynamic economic processes may lead to mismanagement of the fish stocks and result in serious economic consequences for the respective fishing industries. For nearly five decades’ fishery managers and policy makers have used bio-economic models and methods as foundation for their management schemes. These models and methods are for the most based on the deductive methodology of economics where central assumptions are the metaphors of “equilibrium“ and “bio-economic equilibrium“. Models based on equilibrium theories are usually deterministic where dynamics of the markets are a meager part of the problem.Less attention has been offered to inductive reasoning and modeling within the field of fishery management. The inductive method of reasoning is often based on facts and actual observations within the industries, a methodology widely used by engineers and the field of business administration.In this paper, we introduce and integrate the concept of substitutability of economic resources into a traditional bio-economic model. The results show that fishery management, which bases decisions solely on traditional bio-economic models where the dynamics and consequences of the operational decision processes of the industry are ignored, may reach decisions that work opposite of their intention.

The diversity bonus in pooling local knowledge about complex problems

Recently, theoreticians have hypothesized that diverse groups, as opposed to groups that are homogeneous, may have relative merits [S. E. Page, The Diversity Bonus (2019)]-all of which lead to more success in solving complex problems. As such, understanding complex, intertwined environmental and social issues may benefit from the integration of diverse types of local expertise. However, efforts to support this hypothesis have been frequently made through laboratory-based or computational experiments, and it is unclear whether these discoveries generalize to real-world complexities. To bridge this divide, we combine an Internet-based knowledge elicitation technique with theoretical principles of collective intelligence to design an experiment with local stakeholders. Using a case of striped bass fisheries in Massachusetts, we pool the local knowledge of resource stakeholders represented by graphical cognitive maps to produce a causal model of complex social-ecological interdependencies associated with fisheries ecosystems. Blinded reviews from a scientific expert panel revealed that the models of diverse groups outranked those from homogeneous groups. Evaluation via stochastic network analysis also indicated that a diverse group more adequately modeled complex feedbacks and interdependencies than homogeneous groups. We then used our data to run Monte Carlo experiments wherein the distributions of stakeholder-driven cognitive maps were randomly reproduced and virtual groups were generated. Random experiments also predicted that knowledge diversity improves group success, which was measured by benchmarking group models against an ecosystem-based fishery management model. We also highlight that diversity must be moderated through a proper aggregation process, leading to more complex yet parsimonious models.

Implementation of Subgame-Perfect Cooperative Agreement in an Extensive-Form Game

A novel approach to sustainable cooperation called subgameperfect core (S-P Core) was introduced by P. Chander and M. Wooders in 2020 for n-person extensive-form games with terminal payoffs. This solution concept incorporates both subgame perfection and cooperation incentives and implies certain distribution of the total players' payoff at the terminal node of the cooperative history. We use in the paper an extension of the S-P Core to the class of extensive games with payoffs defined at all nodes of the game tree that is based on designing an appropriate payoff distribution procedure β and its implementation when a game unfolds along the cooperative history. The difference is that in accordance with this so-called β-subgameperfect core the players can redistribute total current payoff at each node in the cooperative path. Moreover, a payoff distribution procedure from the β-S-P Core satisfies a number of good properties such as subgame efficiency, non-negativity and strict balance condition. In the paper, we examine different properties of the β-S-P Core, introduce several refinements of this cooperative solution and provide examples of its implementation in extensive-form games. Finally, we consider an application of the β-S-P Core to the symmetric discrete-time alternating-move model of fishery management.

The spatial vulnerability of fisheries resources for sustainable management

Professional management and promoting sustainability have not been well applied in the Sunda Strait waters. Accurate data and information will determine the success of an optimal and sustainable pelagic capture fisheries management model. The purpose of this study was to explore spatial fisheries and analyze the spatial vulnerability of fisheries resources for sustainable management. This research was conducted in the Sunda Strait waters. Data on catches and the distribution of fishing grounds indicate that fisheries conditions in the Sunda Strait are not in good economic and ecological conditions. Excess capacity in a small-scale fisheries area will disrupt the sustainability of fish resources in the area and affect the biomass supply. Management must be carried out by considering sustainability for the long term and contributing to ecological sustainability, economic efficiency and the efforts of the local fishing fleet.

Bioeconomic modeling of seasonal fisheries

Seasonality or periodicity–biological, environmental, or economic–are fundamental properties of most marine fisheries. We propose a generic infinite horizon discrete time fisheries management model by modifying existing models and frameworks of analysis to reflect seasonal variation or more general multiperiodicity in parameters, variables, or functional forms. Our model captures such variations via repeated cycles of multiple intervals with differing characteristics. The framework offers a simple and intuitive set up of arbitrary periodicity and seasonality in any feature, which significantly increases model realism. Further, it distances itself from continuous time modeling approaches where uniqueness and solvability of periodic models generally are difficult to assert. In our setting, the governing equations for the time-dependent value function of the management optimization problem are shown to be equivalent to a high-dimensional contraction and hence ensure uniqueness and a feasible solution algorithm. We illustrate our approach using a simple example to demonstrate that accounting for seasonality in fisheries management can improve outcomes considerably. Our framework also provides for analysis of seasonal regulatory measures. Ultimately, our approach applies to renewable resource management more generally and to many infinite-horizon, discrete time optimization problems with periodic features.

Moving Forward: A Simulation-Based Approach for Solving Dynamic Resource Management Problems

Standard dynamic resource optimization approaches, such as value function iteration, are challenged by problems involving complex uncertainty and a large state space. We extend a solution technique to address these limitations called approximate dynamic programming (ADP). ADP recently emerged in the macroeconomics literature and is novel to bioeconomics. We demonstrate ADP in solving a simple fishery management model under uncertainty to show: the mechanics of ADP in simplest form; the accuracy of ADP; the value of a nonparametric extension; and readily adaptable, non-specialized code. We then demonstrate ADP’s capacity to handle rich bioeconomic problems by solving the fishery management problem subject to four autocorrelated shock processes (governing economic returns and biological dynamics) which entails four sources of stochasticity and five continuous state variables. We find that accounting for multiple autocorrelation has important impacts on harvest policy and generates gains that depend crucially on the structure of harvest cost.

PENERAPAN PRINSIP GOOD GOVERNANCE DALAM PERATURAN PENGELOLAAN PERIKANAN YANG BERKELANJUTAN DI INDONESIA

This study aims to know and analyze and examine the realization of good governance principles in fisheries management regulation in Indonesia; analyze and formulate the ideal fisheries management regulation model in accordance with the concept of good governance.This research is normative juridical research, which is research that puts law as a building of norm system, consisting of principles, norms, rule of law, judgment, agreement, and doctrine. The approach used in this normative legal research is the statute approach and the conceptual approach. The data obtained were analyzed by qualitative method. Based on data analysis, it can be concluded that 1) Realization of 8 Main Characteristics of good governance according to UNESCAP are participation, orientation on consensus, accountable, transparent, responsive, effective and efficient, fair and inclusive and follow the rule of law in law, and efficient that cannot be applied; 2) The ideal fisheries management model in accordance with the principle of good governance is a co-management model, because this model use community empowerment and involve all stakeholders as well.

Using Cellular Automata for Grid-Based Fishery Management

This report introduced new concept and technics for a grid-based fishery management system. The fishing ground was first divided into small grid of equal area, each with predefined longitudes and latitudes (both 0.033 degrees or approximately 2 × 2 nautical miles in this study). All grids were laid and formatted into a Microsoft-Excel spreadsheet system, as defined by the coastline. Individual sheets were also constructed to represent different ecological characters, serving as supporting data of the main grid-map. Including individual fishing record, water depth, wind & current vector, benthic character, etc. Cellular automata (CA) mathematics was applied for simulation studies. They were programmed on the built-in Visual BASIC langrage in EXCEL. In a three-year research project, the author was able to accomplish the following major results: 1) An EXCEL-based spreadsheet system for storage of fishing effort in each grid. Provided that data of fishing yield is also available for each grid, research model for fishery management can be constructed, leading toward solutions for total allowable catch (TAC) as well as maximum economic yield (MEY). 2) A multi-layered, 2-dimentional spread-sheet system demonstrating the distribution of relative intensity for individual grids. The system can be decked up with different ecological data for more advanced studies. 3) Estimation of the nearest distance between two special grids as well as fishing harbors. This would help in more efficient navigation management and allocation of fishing rights for the fishing vessels.

Using a quantitative model for participatory geo-foresight: ISIS-Fish and fishing governance in the Bay of Biscay

This study investigated the use of a complex quantitative simulation model for participatory geo-foresight for the governance of the marine socio-ecosystem in the Bay of Biscay. The approach is simulation-based combining qualitative and quantitative expert-knowledge focusing on the demersal fishery in the Bay of Biscay. A three-stage approach was carried out : (i) translation by stakeholders of a narrative scenario drawn up during the geo-foresight into quantitative sub-scenarios that could be parameterized in ISIS-Fish; (ii) simulation with ISIS-Fish and study of the consequences of the sub-scenarios on the dynamics of the fishery; and (iii) participants feedback on the relevance of the model, on the possibility to detail the narrative scenario further and on the general contribution of ISIS-Fish to geo-foresight. The study created discussions on input data, mechanisms and spatial features of the model and on some limits of simplistic translations of the scenario. The model and simulations highlighted the relevance of using a spatial model to explore sub-scenarios derived from geo-foresight. The flexibility of ISIS-Fish and the synergy between the quantitative modeling and scenario planning approaches allowed for demystification of complex models for fisheries management and illustrated their potential for decision-making for fisheries management.

Density dependence in total egg production per spawner for marine fish

AbstractA paradigm of fisheries science holds that spawning stock biomass (SSB) is directly proportional to total egg production (TEP) of fish stocks. This “SSB–TEP proportionality” paradigm has been a basic premise underlying the spawner–recruitment models for fisheries management and numerous studies on recruitment mechanisms of fish. Studies on maternal effects on reproductive potential of a stock have progressed during the last few decades, leading to doubt concerning the paradigm. Nonetheless, a direct test of the paradigm at multidecadal scales has been difficult because of data limitations in the stock assessment systems worldwide. Here, we tested the paradigm for marine fish based on a novel combination of two independent 38‐year time series: fishery‐dependent stock assessment data and fishery‐independent egg survey data. Through this approach, we show that the SSB–TEP proportionality is distorted by density dependence in total egg production per spawner individual (TEPPS) or spawner unit weight (TEPPSW) at a multidecadal scale. The TEPPS/TEPPSW exponentially declined with biomass and thus was density‐dependent for Japanese sardine, a small pelagic species exhibiting a high level of population fluctuation, in the western North Pacific. By contrast, the TEPPS/TEPPSW was sardine‐density‐dependent for Japanese anchovy, another small pelagic species exhibiting a moderate level of population fluctuation well‐known for being out of phase with sardine. Our analysis revealed intraspecific (sardine) and interspecific (anchovy) density dependence in TEPPS/TEPPSW, which was previously unaccounted for in spawner–recruitment relationships. Such density‐dependent effects at the time of spawning should be considered in fisheries management and studies on recruitment mechanisms.

Challenges in managing freshwater fishery resource through Lebak Lebung Auction approach: a case study in Pangkalan Lampam District Ogan Komering Ilir Regency

Responsible management of fishery resources has been a tradition of Ogan Komering Ilir (OKI) of South Sumatera for generations. It was recorded that since 1630 the Dutch Government had made auction policy for managing water territory in OKI Regency as an effort to preserve nature and to avoid the conflict of inland water ownership. Currently, the community-based management model has been adopted by local governments into formal regulations, known as Regional Regulation on Auction of Flood Water Swamp and Rivers (Lelang Lebak Lebung dan Sungai or L3S). This paper describes the success factors and the threats for the failure of the L3S management model in OKI Regency, based on a case study in Pangkalan Lampam District. The study showed that the management mechanism through the L3S system had been well instituted and become a well-established management practice. The management model is in line with the principle of co-management and the approach has become critical success factor in L3S management. However, ecological, economic and social aspects influence the sustainability of such fishery management model. Besides, L3S management model faces limited data and information related to fish stocks, which result in difficulties in determining the total allowable catch.

Fisheries management under nutrient influence: Cod fishery in the Western Baltic Sea

A fisheries management model that identifies the economic optimal management of fisheries under the influence of nutrients is presented. The model starts from the idea that growth in fish biomass increases with increasing availability of nutrients owing to higher food availability up to a peak, after which growth falls due to eutrophication. The model is applied to Swedish and Danish cod fisheries in the Western Baltic Sea and identifies the welfare contribution of the fisheries, measured as the sum of resource rent and producer surplus. In 2010, the welfare contribution was −28% of the landing value. Maximizing the model with respect to effort alone and additionally over nitrogen concentration increases the contribution to 11% of the landing value in 2010. The analysis shows that the welfare effect of reducing fishing effort through management reforms is large, but that the effect of incorporating nitrogen in fisheries policy is small.

Institutions and collective action in a Costa Rican small-scale fisheries cooperative: the case of CoopeT\xe1rcoles R.L

CoopeTarcoles R.L is a cooperative on the Pacific coast of Costa Rica that has obtained better conditions for its members in the context of small-scale sustainable fisheries for over thirty years. Documents from the cooperative and interviews with diverse stakeholders provided information on the catalytic factors that have made CoopeTarcoles R.L advance towards small-scale fisheries sustainability. A political framework provided by the State concerned with social welfare, the adaptation of the organizational cooperative model to local needs and a community-based governance model for fishery management have been crucial in this regard. Information gathered shows that this collective enterprise has been able to create alternative and gender balanced sources of employment, lead environmental and ecosystem improvement and obtain better prices for fishery products across its three decades of existence. The cooperative, being a local, collective and inclusive initiative, has turned into an engine for community sustainable development, recognizing the value of small-scale fishers’ identity and its importance for the well being of the area. Several factors combined to be crucial for the long-term vision of the fishers in the cooperative and their successful path towards sustainable development. This study highlights the initial support of the government for the creation of a collective organization with adequate infrastructure, the structural changes that led to responsible fishing being promoted by the recognition of a Marine Responsible Fishing Area, and the more equitable relationships supported 15 years ago by another cooperative (CoopeSoliDar R.L.) dealing with human rights and marine conservation.

Rational taxation in an open access fishery model

Abstract We consider a model of fishery management, where n agents exploit a single population with strictly concave continuously differentiable growth function of Verhulst type. If the agent actions are coordinated and directed towards the maximization of the discounted cooperative revenue, then the biomass stabilizes at the level, defined by the well known “golden rule”. We show that for independent myopic harvesting agents such optimal (or ε-optimal) cooperative behavior can be stimulated by the proportional tax, depending on the resource stock, and equal to the marginal value function of the cooperative problem. To implement this taxation scheme we prove that the mentioned value function is strictly concave and continuously differentiable, although the instantaneous individual revenues may be neither concave nor differentiable.

Institutional design of small-scale fisheries in marine protected areas applied to sustainable territorial development on the Brazilian coast

On the Brazilian coast there are many conflicts between Marine Protected Areas (MPAs) and fisher's communities. This research used institutional analysis to integrate studies of sustainable territorial development with coastal fishing in three Brazilian MPAs: the Canavieiras (Bahia) and Itaipu (Rio de Janeiro) Extractive Reserves and the Ecological Station of Tamoios (Rio de Janeiro). Ostrom's Principles (1990) - reviewed by Cox et al. (2010) - were contrasted with the situation of fishing in MPAs in the period of analysis and the fishers' demands for institutional changes. Principles analysis indicated structural weaknesses of the state to promote continuous actions of monitoring resources and users, as well as in the application of graduated sanctions. The design principles most closely associated with the construction of territorial development strategies were related to the rules of appropriation and provision, and nested enterprises. MPAs, as institutional innovations, can act on territorial development dynamics to provide systemic responses capable of preventing the degradation of fisheries resources and marginalisation of users. The sustainable territorial development approach introduces innovative issues for MPAs management, such as territorial identity, integrated production systems and innovation. The perspective on MPAs presented aims to contribute to a quality based fisheries management model, rather than the usual productivity focus.

Non‐parametric modeling reveals environmental effects on bluefin tuna recruitment in Atlantic, Pacific, and Southern Oceans

AbstractEnvironment–recruitment relationships can be difficult to delineate with parametric statistical models and can be prone to misidentification. We use non‐parametric time‐series modeling which makes no assumptions about functional relationships between variables, to reveal environmental influences on early life stages of bluefin tuna and demonstrate improvement in prediction of subsequent recruitment. The influence of sea surface temperature, which has been previously associated with larval growth and survival, was consistently detected in recruitment time series of bluefin tuna stocks that spawn in the Mediterranean Sea, the North Pacific, and the Southern Ocean. Short time series for the Gulf of Mexico stock may have precluded a clear determination of environmental influences on recruitment fluctuations. Because the non‐parametric approach does not require specification of equations to represent system dynamics, predictive models can likely be developed that appropriately reflect the complexity of the ecological system under investigation. This flexibility can potentially overcome methodological challenges of specifying structural relationships between environmental conditions and fish recruitment. Consequently, there is potential for non‐parametric time series modeling to supplement traditional stock recruitment models for fisheries management.

Mathematical Modeling Applied to Sustainable Management of Marine Resources

In this work, we formulate and study a nonlinear mathematical model of fishery management to understand the dynamics of a fishery resource system in an aquatic environment that consists of two zones; one is free fishing zone and another is reserve zone where fishing is strictly prohibited. We have analyzed the model by finding the existence of equilibrium points: biological and bionomic, dynamical behavior of equilibrium points and also derived the conditions of stability and instability of the system. The behavior of this dynamical model of marine fishery management has been illustrated by the numerical simulations to establish the presented analytical results.

Use of a choice-based survey approach to characterise fishing behaviour in a scallop fishery

The predictability of fisher behaviour is an area of considerable uncertainty in fisheries management models. Fisher-derived data could underpin a better understanding, and more realistic predictions of fishing behaviour. Face to face interviews and a choice-based survey were conducted with scallop fishers to collect foraging parameters that could inform a model of fishing behaviour, and to better understand patch choice behaviour. Importantly, we validated survey data against vessel monitoring system and logbook data where possible, demonstrating a good level of accuracy. Environmental parameters central to patch choice were determined (e.g. wave height, distance to port), and three strategies of patch choice behaviour were identified, termed quantity maximiser, quality maximiser, and efficient fisher. Individuals' VMS and logbook data further confirmed and explained these behavioural patterns. This approach provided reliable, highly relevant data for the parameterisation of a fisheries behavioural model, which could lead to more robust and realistic predictive fisheries models.

An integrated model for marine fishery management in the Pearl River Estuary: Linking socio-economic systems and ecosystems

The paper devises an integrated ecological–economics–social model to assess the implementation of ecosystem-based fisheries management in the Pearl River Estuary (PRE) in the South China Sea (SCS). In particular, this paper presents the development of an integrated model, which links a regional economics social accounting matrix (SAM) model to an ecological model constructed using Ecopath with Ecosim (EwE) software. The impacts on the ecological–economics–social system are examined by varying fishing efforts for four scenarios, including status quo management, fishing effort reduction policy, fishing gear switch policy, and summer closure extension policy. Key results from the predictions (2010–2020) and policy simulations illustrate that the collapse effect is apparent in the status quo scenario. Further, reducing or switching of fishing effort (e.g. elimination of overfishing and reduced habitat disturbance) positively affects the ecosystem and can lead to economic and social welfare gains in the PRE's economy. The gear switch scenario presents a compromise among the economics, social, and conservation metrics, and also outperforms other scenarios in terms of biomass at the end of the simulation period. The fishing effort reduction policy performs better than the summer closure extension policy in terms of the conservation metrics but does relatively poorly in economic terms.