The East Atlantic Bluefin Tuna Fisheries: Stock Collapse or Recovery?

A discrete time, multi-gear, and age structured bio-economic model is developed for the East Atlantic bluefin tuna fisheries, a paradigmatic example of the difficulties faced in managing highly migratory fish stocks. The model is used to analyse alternative management strategies for the Regional Fisheries Management Organisation (RFMO) managing this fishery, and to investigate some of the policy implications. For the various scenarios, the optimal stock level varies between 500–800,000 tonnes, which compares with a stock level of 150,000 tonnes in 1995. In other words, there is a very strong case for rebuilding the stock. Moreover, the sustainability of the stock is threatened unless a recovery programme is implemented; indeed, the alternative may be stock collapse. Second, to rebuild the stock, Draconian measures are called for: either outright moratoria over fairly lengthy periods, or possibly a more gradual approach to steady state given by a Total Allowable Catch (TAC) at a low level for an extended period of time. Third, the cost of inefficient gear structure is very high indeed.Bioeconomic model, bluefin tuna, optimal management., Resource /Energy Economics and Policy, Q22,

THE ECONOMIC STRUCTURE OF HARVESTING FOR THREE VESSEL TYPES IN THE NORWEGIAN SPRING-SPAWNING HERRING FISHERY

Norwegian spring-spawning herring (Clupea harengus) is the largest fish stock in the North Atlantic and is harvested by many nations. The introduction of new technology in the 1960s resulted in a substantial increase in the efficiency of the fishing fleet. As a consequence, the stock was fished almost to extinction by the end of the 1960s. In the 1990s, the stock showed healthy growth and Total Allowable Catch (TAC) quotas have increased. This paper adds to the understanding of the harvesting process by providing measurements of the economic structure of the harvesting technology. For this fishery, Norway receives the largest share of the internationally determined TAC quota, and thus, the focus will be to investigate the harvesting process for three vessel types in the Norwegian fishing fleet: purse seiners, trawlers, and coastal vessels. Vessel- level cost and revenue data are available annually for these vessel types for the three-year period 1994–96. Estimates of input elasticities, economies of scale, and cost elasticities for a two-output cost function are reported.Resource /Energy Economics and Policy,

Capital Dynamics in the North Sea Herring Fishery

Dynamic adjustment is an integral part of natural resource economics. Commonly, capital is assumed to respond instantaneously to changes in profits, while in reality adjustment may take place only with a time lag. In this paper, an empirical analysis of capital (boat) dynamics in the North Sea herring fishery is undertaken. A discrete time model is formulated to model decisions of boats to enter or exit the fishery. A lagged model is specified to reflect adjustment time to changes in profits. The empirical results indicate that fleet adjustment in this fishery primarily depends on current period profits and that the opportunity cost may depend on returns in the alternative fishery. Inclusion of lagged variables to account for the construction time for new boats, showed only a small improvement in the statistical fit. Moreover, the results did not support a hypothesis that entry in response to positive profits is more elastic than exit due to negative profits.Environmental Economics and Policy, Production Economics, Resource /Energy Economics and Policy,

Output Substitution in Multi-Species Trawl Fisheries: Implications for Quota Setting

In most multi-species fisheries managed through output controls, total allowable catches (TACs) are set primarily on the basis of biological considerations, usually on a species by species basis. An implicit assumption of management is that fishers are able to adjust their product mix in line with these quotas. If this is not the case, then over-quota catch occurs, leading to either illegal landings or discards. In either case, the effectiveness of the TAC in conserving the resource is reduced. In this paper we show that in the case of multi-species fisheries that exhibit jointness in production, setting TACs on an individual species’ basis is inappropriate. In particular, we quantify technical interactions through the estimation of a multi-output distance function for the UK North Sea beam and otter trawl fisheries, and find that in most cases, the potential of substitutability between the main and alternative species is relatively small. We argue that failure to quantify and integrate these technical interactions in the construction of management instruments for fisheries regulation, may result in increased discarding, illegal fishing and potentially lower than expected future yields.Multi-output fishery, Multi-output distance function, Elasticities of substitution, Efficiency

Social, Economic, and Regulatory Drivers of the Shark Fin Trade

The demand for shark fins is arguably the most important determinant of the fate of shark populations around the world. This paper examines the role that social and economic factors in China play in driving the trade both historically and under current trends of economic growth. The use of shark fin as a traditional and socially important luxury food item, along with rapidly expanding consumer purchasing power is expected to place increasing pressure on available resources. At the same time, the migration of the trade from its former center in Hong Kong to Mainland China has resulted in a severe curtailment of the ability to monitor and assess impacts on shark populations. Although recent international policy responses to this issue have resulted in the implementation of shark finning bans in some areas, these measures are likely to encourage full use of dead sharks; i.e. discourage carcass discards, as called for under the FAO International Plan of Action-Sharks, but not reduce shark mortality.Asia, China, demand, finning, fisheries, management, seafood, Consumer/Household Economics, Demand and Price Analysis, Environmental Economics and Policy, Institutional and Behavioral Economics, International Relations/Trade, Q2,

A BIOECONOMIC ANALYSIS OF THE NORWEGIAN SPRING SPAWNING HERRING (NSSH) STOCK

A biological model belonging to the Beverton-Holt age-structured family for the Norwegian spring spawning herring (Clupea harengus) (NSSH) is simulated, the outcome of which compares well with actual data on the fishery. This model is then combined with an economic model to help investigate how optimal a management policy of constant fishing mortality will be for a fishery such as the NSSH, which has a highly fluctuating stock biomass. For the range of constant values of fishing mortality explored, and a simulation time horizon of 20 years, a constant fishing mortality of 0.15 turns out to be economically optimal. It should be noted that this result is sensitive to variations in the assumptions underlying key variables of the fishery. For example, when a constant rather than variable recruitment was assumed, a different optimal fishing mortality rate was obtained.bioeconomic model, herring optimal management, Resource /Energy Economics and Policy, Q57, Q22, Q28,

Price transmission in seafood value chain. Case study in Spain shows retailers favor farmed products.

An FAO research project that studied value chains for wild and farmed seafood analyzed the impacts of varied market conditions on the transmission of prices from farms to consumers. Changes in retail prices were less pronounced than in producer or wholesaler prices, as retailers tended to flatten price variations. Value added by wholesalers was higher for wild species with limited imports. Retail farmed fish prices were more closely linked with the evolution of pricing across the value chain

A Comparative Index Characterization of Shrimp Farms in Bangladesh, India and Indonesia

The purpose of this paper is to provide a comparative index characterization of shrimp farms in Bangladesh, India and Indonesia. There has been considerable work carried out on shrimp farming in South East Asia with emphasis on biology, environmental factors, management and trade issues but much less work on the economic characterization of shrimp farms. The index approach used in the paper allows for a decomposition of profits measuring the relative importance of output and input prices, pond size utilization and productivity. This is possible by transforming the variables using an index decomposition technique, which is an application of Törnqvist index number theory. The unique properties of the Törnqvist index allow for the combined effect of the different economic factors to be aggregated in measuring changes in profitability. The index approach does not impose economic behaviour on the farms but rather is an accounting approach to the contribution of each factor input to profitability. In this way, changes in profitability can be decomposed into changes in the individual factors of production with the residual change in profitability defined as productivity. For Bangladesh data are available on an unbalanced panel of 190 farms for the period 1998 to 2002. For India data are available on an unbalanced panel of 30 farms for the period 2000 to 2002. For Indonesia data are available on a cross section of 125 farms for 2002. The decomposition index will be applied to each data set allowing a comparative index characterization across farms

The Management of High Seas Fishery Resources and the Implementation of the U.N. Fish Agreement of 1995: Problems and Prospects

Abstract only.The U.N. Agreement, arising from the U.N. Conference on Straddling Fish Stocks and Highly Migratory Fish Stocks, 1993-1995, is close to achieving the number ratifications required to enter into force. The Agreement is, moreover, currently serving as a framework for the cooperative management of several straddling and highly migratory fishery resources in various parts of the world. The long term viability of the U.N. Agreement is, however, far from being assured. Straddling and highly migratory fish stocks constitute a class of transboundary fishery resources that are particularly difficult to manage effectively. This paper reviews the history of the U.N. Agreement, attempts to implement the Agreement, and analyses, with the aid of game theory, two problems, arising from the Agreement, which remain unresolved at this time. Either problem, should it remains unresolved, could undermine the Agreement. The paper extends earlier discussions of the issue by drawing upon the results of a recently completed two year research project: “The Management of High Seas Fisheries”, and upon the results and conclusions of a conference on “The Management of Straddling Fish Stocks and Highly Migratory Fish Stocks and the U.N. Agreement”, held in Bergen last year