Managing competing interests in aquaculture development: Can conflict resolution modelling help decision making?

The bountiful resources of the oceans are indispensable for the survival and welfare of communities around the world. Accordingly, it is not surprising that economic activities linked to our oceans are significantly expanding within a highly competitive environment among countries and other interest groups. Importantly, the oceans provide a valuable food supply for humanity both from the natural harvesting of the ocean’s sea life, as well as from aquaculture.

At the global level, aquaculture is considered as one of the fastest growing food-producing sectors, currently furnishing about half of the fishery products consumed by people. In comparison to wild fishing, during the past quarter of a century aquaculture’s contribution to the food supply has almost quadrupled, from 13 to 45 per cent. Although this rapid expansion has provided significant benefits to some groups, it has also raised numerous concerns to others. Due to the fact that conflict often arises among competing interest groups participating in marine economic activities, such as aquaculture expansion, decision tools for addressing conflict have a crucial role to play in marine economics and management.


In this study, the Graph Model for Conflict Resolution (GMCR) is introduced and illustrated for resolving a real-life dispute arising over aquaculture development in the Province of British Columbia, Canada. In practice, GMCR constitutes a powerful technique for finding possible resolutions to conflict situations involving many different stakeholders or decision makers (DMs) having various types of interests and behavioural characteristics.

GMCR possesses several unique and fundamental advantages in contrast to other approaches to conflict analysis, including that it:

  • Only requires limited information to calibrate;
  • Contains a rich range of solution concepts, or stability definitions, that describe how a DM may think and behave under conflict;
  • Delivers a variety of informative output, follow-up analyses, and advice for use in real-life decision support;
  • Can be programmed within decision support systems (DSSs) that allow practitioners and researchers to readily apply the GMCR methodology to real-life disputes.

The GMCR methodology consists of two main stages: modelling and analysis, as depicted in Figure 1. In the modelling phase, basic information such as the DMs and their options are first input, and then a set of states is formed based on which options are selected by the DMs controlling them. Subsequently, a ranking of all of the feasible states separately for each DM is determined by using a number of means such as preference statements or weights. In the analysis stage, one can determine which states are stable for a DM according to various solution concepts. If a state is stable for all of the DMs, it forms an equilibrium or possible resolution to the conflict being investigated. As shown in the centre of Figure 1, one can check if co-operating with other DMs by joining a coalition can result in a better final outcome for a given DM.Table 1

Figure 1: Main components of the graphic model for conflict resolution methodology


In the case study conflict model, five DMs were identified: aquaculture industry and its supporters (AIS), First Nations (FN), environmental groups (EG), residents (Res) and government (Gov). A summary of the key DMs and the decision options under their control are listed in Table 1. The option prioritizing method was utilized to obtain a ranking of states separately for each DM. Stability calculations were then carried out for determining the stability of every state for each DM under various solutions. States that were equilibria under competition, or that might become equilibria through coalition, under at least one solution were further examined to provide strategic insights.

Based on the individual and coalitional stability results, and the evolution of this generic aquaculture conflict over time, it was concluded that the AIS and Gov are the two main drivers of the findings. In particular, it is highly likely that when the government makes a decision, the AIS would respond and comply with the policy chosen by the government. In each possible resolution, at least two DMs among FN, EG and Res would object to the expansion because of the assumption that the government would decide to appease just one stakeholder at a time. Additionally, in each potential resolution, if AIS chooses to satisfy the interests of one stakeholder, then that group would likely be satisfied with the outcome and not oppose the expansion. The results also suggest one situation in which the government prefers economic growth to environmental protection and approves new expansion requests in spite of the opposition of many affected groups. Hence, it is challenging to balance the interests of the different stakeholders.

Table 1

Table1: Key decision makers and their options


A key motivating factor for originally creating GMCR was to design and build a decision methodology having the innate capability to address challenging decision situations taking place in water resources and environmental management. The application of the GMCR to the aquaculture dispute systematically studied in this paper demonstrates that GMCR can provide valuable strategic insights for improving the decision-making process.

With respect to resource management, the investigation demonstrates how difficult it can be to balance the interests of different stakeholder groups in aquaculture development. In particular, for each possible conflict resolution, at least two DMs among First Nations, environmental groups, and residents would object to the extension of aquaculture activities.

The case study also points out the need for a useful tool box of decision technologies for addressing the vast array of challenges that could arise in marine economics and management. Overall, the management and governance of valuable marine resources should be integrative, by accounting for interconnections among systems, and adaptive in order to be able to respond to emerging properties or changes that could appear from complex ocean systems. In addition, as illustrated in this study, the value systems or preferences of the key stakeholder groups should be taken into account. In this way, fairness, robustness, sustainability and other important desirable system characteristics can be maintained.


Hipel, K.W., Fang, L., Xiao, Y. (2018). Managing conflict in aquaculture, Marine Economics and Management, 1:1, 1-19,
https://doi. org/10.1108/MAEM-06-2018-001

Contact: Keith Hipel, Department of Systems Design Engineering

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