Unravelling complex interactions between urbanisation and coastal fisheries using a system dynamics approach

Abstract

Coastal zones are amongst the most heavily populated and exploited areas in many parts of the world. Burgeoning coastal urbanization and resource use is increasingly giving rise to conflict among users of coastal resources. One such conflict arises from wastewater disposal in urban areas causing degradation of coastal water quality and pollution impacts on other uses, such as fishing. This is especially significant in developing countries, where subsistence fishing is very important to coastal communities that rely on their catches as a source of food and for their livelihoods. Thus urbanisation in coastal areas is often a factor contributing to devaluing of ecosystem goods and services, and can impact other uses, such as subsistence fisheries. Natural questions which arise are how severe is this impact, and what could be done to mitigate, or at least minimize it? In this project we aim to develop a decision-support tool to support non-technical decision-makers in data poor environments to reach realistic solutions in these complex socio-ecological systems without having to rely on detailed data and information. Specifically, we focus on potential conflict between land-based wastewater inputs from a city on a coastal fishery. This paper presents a simplified conceptualization of the key elements in this conflict situation, and proposes a preliminary design of a system dynamics model. This model will be refined in an expert workshop forum as part of the next stage in this project. Once calibrated, the model will be used to test various wastewater scenarios, so as to assist in unravelling this complex interaction and, most importantly, inform future mitigation needs.