Boundary conditions for the sustainable use of major fish stocks in the Baltic Sea

The history of the management of Baltic fishery resources suggests that both biological and non-biological factors influence management decisions and that both types of information are essential for management which promotes sustainability. There is a direct link between the exploitation level and the risks for fishing as an economic activity due to fluctuations in the resource. This paper analyses the sustainability of the present catch levels of major Baltic fish stocks. By examining the rate of fishing mortality and recruitment variability, the possibility of sustaining present catch levels can be investigated. Current catch levels of Baltic cod and some salmon stocks are not sustainable whereas sprat and herring catches are. High rates of fishing mortality of cod and salmon may endanger stocks if a drop in the recruitment causes an increase of the fishing mortality rates in order to sustain short-term catches. By analysing the trade off between exploitation level and risk of stock decline, managers can obtain a basis for quota negotiations.     

Cooperative and non-cooperative management of the Northeast Atlantic cod fishery

The fishery for Northeast Atlantic cod (Gadus morhua) in the Barents Sea is one of the most valuable fisheries in the North Atlantic. After the introduction of Extended Fisheries Jurisdiction, cod is a shared stock between Norway and Russia. Overfishing of quotas has been a concern for a number of years. The purpose of this article is to analyse cooperative and non-cooperative management of the Northeast Atlantic cod fishery. This will be done in a game theoretic context, based on different assumptions regarding important variables such as cost of effort and initial stock size. The game theoretic analysis will be based on an empirical bioeconomic model developed and estimated by Hannesson (Mar Policy 31:698–705, 2007; J Bioecon forthcoming). The case of cooperative management is analysed for different cost parameters and starting values of the stock. An interesting result is that the optimal policy gives rise to pulse fishing. As this involves effort (and harvests) varying from year to year, potentially imposing substantial social costs on the industry in years when the fishery is closed, a policy of constant effort is also considered. Finally, non-cooperative management is analysed.     

Economic versus physical input measures in the analysis of technical efficiency in fisheries

The measurement of technical efficiency requires the estimation of an appropriate production frontier. This is based on a set of inputs that are assumed to influence the level of output. Deviations from this frontier production function are separated into random variation and inefficiency. However, mis-specification of the production function through the use of inappropriate input measures may result in a bias in the measures of inefficiency. In fisheries, production is generally assumed to be a function of stock size, fishing time and the level of physical inputs employed. Defining the appropriate levels of physical inputs, however, is not straightforward, and several alternative measures are available. While economic measures of capital are more intuitively appealing, physical measures are generally readily available and hence less costly to collect. In this study, technical efficiency is measured for three fleet segments operating in the North Sea using three different gear types. The effects of using different measures of capital in the production frontier on the efficiency estimates are examined.     

A model for estimating fish population and optimal fishing effort in lakes and rivers

We developed a model for estimating the fish population for various species in lakes and rivers. Our estimation focuses, in its first step, on fish species that breed outside the lake. Using the annual outside supply of fingerlings, natural survival rate and reported amounts of fish caught, we estimated fish stock. Given the estimated stock for fish bred outside the lake, we can evaluate the catch rate. Assuming equal catch rates for other species, and given the amount caught for each species, we are able to evaluate each species stock. Using the proposed technique, we evaluated various species stocks in the Sea of Galilee (Lake Kinneret) in Israel. Using our suggested technique for evaluating fish stock, we calculated the optimal effort of fishing needed for maximizing steady state profit of the fishers.     

Food security implications of global marine catch losses due to overfishing

Excess fishing capacity and the growth in global demand for fishery products have made overfishing ubiquitous in the world’s oceans. Here we describe the potential catch losses due to unsustainable fishing in all countries’ exclusive economic zones (EEZs) and on the high seas over 1950–2004. To do so, we relied upon catch and price statistics from the Sea Around Us Project as well as an empirical relationship we derived from species stock assessments by the U.S. National Oceanic and Atmospheric Administration. In 2000 alone, estimated global catch losses amounted to 7–36% of the actual tonnage landed that year, resulting in a landed value loss of between 6.4 and 36 billion (in 2004 constant US6.4 and 36 billion (in 2004 constant US). From 1950–2004, 36–53% of commercial species in 55–66% of EEZs may have been overfished. Referring to a species-level database of intrinsic vulnerability (V) based on life-history traits, it appears that susceptible species were depleted quickly and serially, with the average V of potential catch losses declining at a similar rate to that of actual landings. The three continental regions to incur greatest losses by mass were Europe, North America, and Asia—forming a geographic progression in time. But low-income and small island nations, heavily dependent on marine resources for protein, were impacted most profoundly. Our analysis shows that without the inexorable march of overfishing, ~20 million people worldwide could have averted undernourishment in 2000. For the same year, total catch in the waters of low-income food deficit nations might have been up to 17% greater than the tonnage actually landed there. The situation may be worst for Africa, which in our analysis registered losses of about 9–49% of its actual catches by mass in year 2000, thus seriously threatening progress towards the UN Millennium Development Goals.     

Testing theoretical explanations for investment behaviour in the Dutch beam trawler fishery in the North Sea

In this study, we investigate whether the neoclassical economic theory, capital market frictions or preference-based theory can explain investment behaviour in the Dutch beam trawler fishery in the North Sea. By presenting a number of estimations, we show that vessels conducting pulse fishing invest substantially more than similar vessels undertaking conventional fishing, even after controlling for differences in such variables as capital stock, prices, profits and quotas. One possible explanation for this result is that vessel owners may obtain a separate benefit from investing in pulse fishing.     

Portfolio Fishing

The optimal fishing pattern in a multi-cohort fishery is determined using risk theory.Portfolio theory becomes applicable by treating different age groups of fish as different assets. A possibility set is derived using data on Icelandic cod fisheries. In the presence of risk aversion, it is shown that the abrupt behavior found in deterministic models is changed towards a smoother fishing pattern. The historical selection pattern for the Icelandic cod stock is shown to be near optimal using a maximal effort-type cost function, but historical levels of effort are inefficient and lead to less profit and greater fluctuations than implied by profit or utility maximization.     

Cooperative and Non-Cooperative Exploitation of the Arcto-Norwegian Cod Stock

A two-agent model for the exploitation of the Arcto-Norwegian cod stock is developed to investigate the economic benefits that can be realized from the resource, and the effect of exploitation on stock sustainability under cooperation and non-cooperation. The two agents are identified in this study as a trawl fishery versus a coastal fishery. Unlike in Munro (1979), where conflicts in the management strategies of agents arise from differences in the perceptions of the discount factor, fishing effort costs, and consumer preferences, here conflicts arise mainly from the differences in fishing gear and grounds, and the age group of cod targeted by the two agents. Using a game theoretic framework, we show that given available data, the optimum optimorum is obtained under cooperation with side payments and no predetermined harvest shares, in which case the coastal fishery buys out the trawl fishery. However, sensitivity analysis shows that if the price premium assumed for mature cod is taken away, the trawl fishery takes over as the producer of the optimum optimorum.     

Optimal Harvesting of an Age-Structured Schooling Fishery

Biologists have criticized traditional biomass models in fishery economics for being oversimplified. Biological stock assessment models are more sophisticated with regard to biological content, but rarely account for economic objectives. This study includes a full age-structured population model for studying schooling fisheries and extends the delayed difference approach used in earlier studies. We take the total harvest as the choice variable, resulting in a simple analytical structure. The model produces optimal steady states that may be higher or lower compared to the delayed-difference formulation. The model is applied to the Baltic sprat fishery. Both ecological and harvesting cost data support specifying Baltic sprat as a schooling fishery. Given nonlinear harvesting costs, the optimal solution is a path toward a steady state with smooth annual harvest and population age structure. Sensitivity analysis shows that the optimal solution is highly dependent on the population level of the sprat’s main predator Baltic cod. A linear cost function and an interest rate below 9 % imply pulse fishing instead of smooth continuous harvesting. Given nonlinear harvesting cost, the optimal steady state yield is rather insensitive to changes in the interest rate. However, under a high cod scenario, interest rates of 10 % or higher implies that no optimal steady state exists.     

Enjoying Catch and Fishing Effort: The Effort Effect in Recreational Fisheries

Recreational fishermen derive utility from catch and fishing effort. Building our analysis on the Gordon-Clark model for renewable resources, we show that a lower importance of catch may result in higher catches. While this effect also holds under first-best management, it may destabilize open-access recreational fisheries to the point of stock collapse. Technical progress in recreational fisheries may mask such dynamics as it enables unaltered angler behavior and constant catches during stock declines.     

Variable unit costs in an output-regulated industry: The Fishery

Departing from general cost theory of the firm and bioeconomic theory of the fishery, this study contributes with an empirical examination of how variable unit costs in a Norwegian demersal and pelagic fishery depend on output and the fish stock. The identification of the separate effects that the two factors have on costs is not common in the literature. Three Norwegian fleets fishing Norwegian spring spawning herring (Clupea Harengus) and five Norwegian fleets fishing Northeast Arctic cod (Gadus Morhua) are evaluated. The findings indicate that variable unit costs fall in output in both fisheries. The results also show that variable unit costs fall in fish stock in the demersal fishery, but with a stock elasticity of variable unit costs in absolute terms significantly less than 1. These results are of relevance to a manager seeking the optimal harvest rule and to understand fishermen's incentives when individual vessel quotas are reduced.     

Does the Optimal Size of a Fish Stock Increase with Environmental Uncertainties?

We analyze the effect of environmental uncertainties on optimal fishery management in a bio-economic fishery model. Unlike most of the literature on resource economics, but in line with ecological models, we allow the different biological processes of survival and recruitment to be affected differently by environmental uncertainties. We show that the overall effect of uncertainty on the optimal size of a fish stock is ambiguous, depending on the prudence of the value function. For the case of a risk-neutral fishery manager, the overall effect depends on the relative magnitude of two opposing effects, the ‘convex-cost effect’ and the ‘gambling effect’. We apply the analysis to the Baltic cod and the North Sea herring fisheries, concluding that for risk neutral agents the net effect of environmental uncertainties on the optimal size of these fish stocks is negative, albeit small in absolute value. Under risk aversion, the effect on optimal stock size is positive for sufficiently high coefficients of constant relative risk aversion.     

ITQ Systems in Multifleet Fisheries

Optimum management of a particular fishery is analyzed based on an ITQ system. For this purpose, a multifleet deterministic bioeconomic model is developed and applied. Using data on the fishery studied here, estimates are made of the stock dynamics of fish and the technology used by the fleets operating in said fishery. Optimum levels of stock, effort and catch are determined. Finally, we present economic policy recommendations for this fishery and considerations for applying regulatory measures.     

Measuring potential profits in a bioeconomic model of the mixed demersal fishery in the North Sea

This paper measures for potential profit in the North Sea mixed demersal fishery for cod, haddock and whiting. Dynamic bioeconomic models for three UK fisheries are developed, incorporating both population dynamics and economic structure. Actual profit in 2006, for the three UK fleets included in the analysis, is estimated at ??10.3?million. If the TAC remains unchanged but vessels are allowed to harvest at near efficient levels with fleet size reduced accordingly, potential profit is measured at ??34.5?million. If demersal stocks are allowed to recover to near optimal levels potential UK profit exceeds ??185?million. This indicates substantial profit dissipation due to overcapacity and stock depletion in the fishery. The results of the paper should be of policy interest and will add to the empirical literature on resource profits in mixed demersal fisheries.     

Endogenous Fishery Management in a Stochastic Model: Why Do Fishery Agencies Use TACs Along with Fishing Periods?

This paper seeks to explain the circumstances under which using total allowable catch (TAC) as an instrument to manage a fishery along with fishing periods may be of interest from a regulatory point of view. The deterministic analysis by Homans and Wilen (J Environ Econ Manag 32:1?C21, 1997) and Anderson (Ann Oper Res 94:231?C257, 2000) is thus extended to a stochastic scenario where the resource cannot be measured accurately. The resulting model is solved numerically to find the optimal control rules in the Iberian sardine stock. Three relevant conclusions can be highlighted from simulations: first, the greater the uncertainty regarding the state of the stock, the lower the probability of the fishery being closed before the end of the fishing period. Second, the use of TACs as a management instrument in fisheries that are already regulated by fishing periods leads to: (i) an increase in the optimal season length and harvests, especially for medium and high numbers of licences; (ii) improved biological and economic variables when the fleet is large; and (iii) extinction risk for the resource being eliminated. Third, the regulator would rather select the number of licences than restrict the season length.     

Modelling the economic consequences of Marine Protected Areas using the BEMCOM model

This paper introduces and describes in detail the bioeconomic optimization model BEMCOM (BioEconomic Model to evaluate the COnsequences of Marine protected areas) that has been developed to assess the economic effects of introducing Marine Protected Areas (MPA) for fisheries. BEMCOM answers the question ‘what’s best?’, i.e. finds the overall optimal effort allocation, from an economic point of view, between multiple harvesting fleets fishing under a subset of restrictions on catches and effort levels. The BEMCOM model is described and applied to the case of the Danish sandeel fishery in the North Sea. It has several times been suggested to close parts of the sandeel fishery in the North Sea out of concern for other species feeding on sandeel and/or spawning in the sandeel habitats. The economic effects of such closures have been assessed using BEMCOM. The results indicate that the model yields reliable estimates of the effect of MPAs, and can thus be a valuable tool when deciding where to locate MPA.     

Directional measurement of technical efficiency of production: An axiomatic approach

This contribution revisits the debate on the axiomatic properties satisfied by various radial versus non-radial measures of technical efficiency in production. This issue arises whenever isoquant and efficient subset of technology diverge and hence traditional radial measurement does not comply with Koopmans' definition of technical efficiency. This axiomatic approach to technical efficiency measurement is revisited within the framework of the more recently introduced directional distance function. This analysis provides the opportunity to define some new directional efficiency measures.     

Slack-based directional distance function in the presence of bad outputs: theory and application to Vietnamese banking

In this paper we extend the slack-based directional distance function introduced by Färe and Grosskopf (Eur J Oper Res 200(1):320–322, 2010) to measure efficiency in the presence of bad outputs and illustrate it through an application on data of Vietnamese commercial banks. We also compare results from the slack-based directional distance function relative to the directional distance function, the enhanced hyperbolic efficiency measure (Färe et al. in Rev Econ Stat 71(1):90–98, 1989) and the Farrell-type technical efficiency and confirm that it has greater discriminative power.     

Economic and conservation implications of a variable effort penalty system in effort-controlled fisheries

Bycatch of threatened, endangered or protected species by commercial fishers is a universal problem. Technical solutions are often applied that may impose inefficiencies across the fleet, even in periods or areas when the risk of bycatch is low. These may include gear specifically designed to avoid the bycatch which may also reduce the targeted catch, or designation of marine protected areas that exclude fishing from whole areas. In this article, we examine the effectiveness of a variable penalty system that can provide incentives for fishers to redirect their effort away from problem areas. The system is examined using a case study of fishery, which is currently subjected to gear and closure controls to limit bycatch of turtles and seabirds. An alternative incentive-based management policy using a series of differential hook penalties has been proposed as a flexible tool to discourage vessels operating in certain areas. The effects of various hook penalties and closures in key areas on fishing effort in those areas and elsewhere as well as vessel economic performance are assessed using a location choice model. The results suggest that incentive-based approaches may result in lower costs to industry than closures provided some level of residual bycatch is acceptable.     

Transferable quotas,enforcement costs and typical firms: An empirical application to the Norwegian trawler fleet

An alternative to traditional regulations of fisheries to avoid rent dissipation is the use of individual transferable quotas (ITQ _s ) where prices in the quota market provide the necessary information to owners of harvest rights to contract with each other. However, even under such a decentralized regime, information on the underlying technology of the fishing vessels is also necessary. First, since most fisheries consist of many interrelated production processes, in order to avoid rent dissipation by discarding wrong output mix etc., the structure of production in the multispecies fishery must be known to design a proper quota system. Second, an ITQ system may create incentives for misreporting by understating the actual catch. This may especially be the case where the expected degree of self-enforcement is low. The paper proposes a way to reduce the information requirements under regulation with asymmetric information by constructing a typical firm and comparing performance for the other vessels to this firm. Based on the typical firm, and if the industry is relatively homogenous, the performance and hence catch of any other firm in the industry can be predicted within a certain range. Further, the paper applies this idea to the Norwegian trawler fleet to assess the production structure in terms of jointness, input-output separability, and the supply and demand elasticities for the fishing firms. This information characterizes the fishery and thus how the quota system may be designed and how to construct a yardstick in order to reduce the enforcement cost under a decentralized regulation of ITQs.The authors would like to thank Trond Bjørndal, Røgnvaldur Hannesson, Ola Flaaten and two referees for useful comments and suggestions.