The Dynamics of an Open Access: The case of the Baltic Sea Cod Fishery - A Strategic Approach -

The paper sets up a discrete-time, deterministic model of a single industry, in the light of the benchmark theory of Smith (1968). The model is used to de-scribe the dynamics of recovery from a replenishable resource such as the case of the eastern Baltic Cod fishery. The model advances from Smith’s (1968) theory since it includes a biological function dividing the change in the biomass into growth occurring during the year and recruits entering the spawning stock biomass and a dynamic entry/exit function applying a slightly more technical production function than the Schaefer production function. Theoretical possible types of steady state are discussed before the theory is applied to the eastern Baltic Sea cod fishery. The path the fishery has been following since 1982 is determined and it is discussed how it relates to the optimal path to steady state. The paper further throws light on questions as; Are we able to understand the dynamic behavior of fishermen in this fishery? Does a stable equilibrium exits and how is the path to this equilibrium described? When a fishery is regarded outside safe biological limits, could it be on the path to a positive steady state?

On Species Preservation and Non-Cooperative Exploiters

Game-theoretic fisheries models typically consider cases where some players harvest a single common fish stock. It is, however, the case that these types of models do not capture many real world mixed fisheries, where species are bio-logical independent or dependent. The present paper considers cases where several non-cooperative exploiters are involved in mixed fisheries. This paper is targeting biodiversity preservation by setting up a two species model with the aim of ensuring both species survive harvesting of exploiters adapting a non-cooperative behaviour. The model starts out as a multi-species model without biological dependency and is then modified to include also biological dependency. We contribute to the literature by analytically finding the limits on the number of players preserving both species including the conditions to be satisfied. For visual purposes we simulate a two species model with different kind of interrelationship.Biodiversity preservation, non-cooperative game, multi-species fisheries, bio-economic modelling

An Enforcement-Coalition Model: Fishermen and Authorities forming Coalitions

The paper sets up a four-stage enforcement model of fish quotas. The purpose of the paper is to show how the level of enforcement set by the authorities af-fects the way fishermen form coalitions. We show that a high level of control effort yields less cooperation among fishermen, while in the case of low control effort, coalitions are somewhat self-enforcing. The paper further discusses how the optimal enforcement level changes when the coalition formation among au-thorities changes: centralised, partly centralised and decentralised authorities. We show that decentralised authorities set a lower level of control effort com-pared to the centralised authorities. The theoretical results are illustrated by simulations of the Baltic Sea cod fishery.Coalition formation, Fisheries management, Quota enforcement, Self-enforcing policy

The Two-sector Economic Problem Of Persistent Organic Pollution and Baltic Sea Salmon Fisheries

The paper describes the general nature of two-sector environmental and natural resource problems and highlights the issue of two sector models where one sector imposes a one-sided negative externality on the other sector, e.g. the polluting sector causes changes in the economic value of the fishery sector. The paper sets up a general social planner model and demonstrates it in simple functional form, using the problem of persistent organic pollution in the Baltic Sea and its effects on the regulation and economic value of the Baltic Salmon. The paper illustrates how a modified golden rule can be used to describe the optimal link between the two sectors

Parallel Agreements in Fisheries Mangamenet

Many commercial fisheries around the world experience spatial coexistence of species and imperfectly selective harvesting gears. This makes these fisheries multi-product industries, that often harvest multispecies or have a bycatch of another (maybe also valuable) species, which may or may not be target species for another fishery. Traditional game theoretic fisheries literature often ignores this above sea interlink of species when applying one species models. Also, in the management setting the interlink between species above sea level is often ignored since these species are managed both biologically and economical separately. This paper explores the biological and the economic consequences of ignoring this interlink, thus making separate management agreements instead of parallel agreement in both a cooperative and a non-cooperative framework. The paper shows that there will always be economic gain from including the knowledge about the interlink in the joint management of species, but the biological consequences for stocks is ambiguous and very dependent on the economic importance of the species. Our results are illustrated by applying the model to the mixed trawl fishery in Kattegat and Skagerrak where there is coexistence in habitat of cod and Norway lobster.Keywords: Fisheries Economics, Modeling and Economic Theory, Fisheries Modelin

Robustness of Sharing Rules Under Climatic Changes - The Case of International Fisheries Agreement

Many international fisheries agreements involve sharing rules. These rules are normally stable rules, not contingent on shifts in the relative distribution or development of the resource. In the latest IPCC report, the most likely future scenario is an increase in the global mean temperature, and most severely in high latitudes. The lack of robustness of management systems of shared fish stocks with respect to exogenous changes has been addressed in several papers (see e.g. [14,15]). A more rigorous game theoretic analysis of sharing rules and their robustness with respect to especially economic parameters has been conducted in [12]. Their approach introduces a connection between cooperative games (sharing rules) and non-cooperative games (stability) and seems in particular suitable for a theoretic analysis of which type of sharing rules are robust. Our contribution is to analyze the possibility of finding sharing rules that can cope with long run changes in the composition of the fish stocks in an international setting due to climate change. The exploitation of the cod stock in the Baltic Sea serves as an illustrative example

Application of Game Theory to Intra-EEZ Fisheries Management

The purpose of this paper is not to present new game theoretic results, but is rather to discuss a new and much needed research program, which is at an early stage.  Progress to date will be reported upon. It is the contention of the authors that, in stark contrast to the management of international fisheries, the application of game theory to intra-EEZ (intra-EU) fisheries management has been extremely limited. The need for game theoretic analysis arises from the fact that there is increasing evidence of attempts to foster cooperation among fishers in intra-EEZ fisheries, which involves self-management (in the spirit of Elinor Ostrom), co-management and blends of the two. A case study from Canada will be brought to bear to motivate the discussion. The case study involves an ITQed fishery, spread over a broad area and involving a large number of ITQ holders. Received wisdom would see prospects for achieving effective intra- industry cooperation in this case as being remote. Nonetheless, the industry initiated a cooperative undertaking with a coalition of environmental NGOs, with the resource manager (the government of Canada) playing a supportive but passive role, resulting in the world's first habitat bycatch limitation scheme. Representatives of the industry and of the NGOs were recently the joint recipients of a major aquatic conservation award. The relevance of the Canadian case to the rest of the world cannot be assessed, until it has been studied and analysed through the lens of game theory.Proceedings of the Eighteenth Biennial Conference of the International Institute of Fisheries Economics and Trade, held July 11-15, 2016 at Aberdeen Exhibition and Conference Center (AECC), Aberdeen, Scotland, UK

Bio-Economic Evaluation of Implementing Selective Gears

The lack of selectivity in many fisheries may lead to discards and bycatch. Discards of under-sized or non-commercial species/individuals represent damage to the eco-system, an additional source of overfishing and a waste of resources. Bycatch may increase fishing pressure on species targeted by other fishermen. The purpose of the paper is to investigate in a bio-economic model the scope for implementing more selective gears in the Danish mixed nephops fishery in Kattegat/Skagerrak. The bio-economic model is developed in such a way that it can illustrate biological changes and the resulting changes in both the profit of fisherman and the net-benefit from a social point of view. The results are based on a detailed biological model, where it is possible to handle both the changes in size- and species composition of catches, landings and discards due to changes in selectivity. The result shows that it is not an advantage to move to gear types that reduces the catches of round- and flatfish significant. The catches of nephrops do also decrease and the resulting improvements in stock biomass do not compensate enough for the overall loss due to the lower catches. However, a general improvement in mesh size improves the overall economic results from the fishery.Keywords: Dansh mixed nephops fishery, Fisheries, Selective gears, Fisheries Economics, Discards and bycatch, Bio-economic evaluatio