Towards a better understanding of small-scale fishing decisions and their consequences in Northern Mozambique
Authors:   , Heckendorn Katrina Ann 
Published: May 2024

This study investigates the relationship between the interacting social and ecological systems within the Pemba Bay fishery, in Northern Mozambique, as mediated by fishing decisions. All ecosystems in the world are affected by human behaviours in some way. In many cases, human effects on ecosystems are detrimental to many other species and can cause shifts in the entire system. In fisheries, the connections between human behaviours and ecosystems are obvious, as fishers extract wild populations of marine species. Human behavioural plasticity and sometimes rapid cultural evolution allow human behaviours to change and adapt faster than many other species can respond which often allows fishers to overexploit marine ecosystems. Many fisheries in the world are fully, or over exploited. Managing these fisheries often focuses on changing those highly adaptable human behaviours. Fishers’ motivations for making different fishing decisions as well as attitudes towards the fishery can be used to understand human interactions with ecosystems when the dependence between the two is direct, as well as allowing managers to tailor interventions that account for fishers’ motivations and attitudes. Most fisheries’ management projects assume that behaviours are motivated by profit maximization. This study investigates this assumption by comparing the compatibility of interview responses and fishing behaviours with rational actor theory, which assumes profit maximization is the only goal. Responses are also compared with prospect theory, which emphasizes reliability of outcomes; descriptive norms, which focuses on social interactions; habitual behaviour, which assumes most decision are automatic based on habit; and theory of planned behaviour, which allows attitudes to be shaped by economic or non-economic motivations, as well as peer opinion and incorporates perceived behavioural control in making decisions. These behavioural theories span a variety of potential fisher motivations which could affect fishing decisions. The study then investigates the state of the social and ecological systems which have resulted, at least in part, from those fishing decisions, and makes recommendations on possible interventions to improve the system based on better understanding of fishers’ attitudes and motivations. The study tests the hypothesis that fishers are motivated primarily by profit maximization and, therefore, rational actor theory is most compatible with fishers’ stated motivations for fishing, or alternatively, that one of the other behavioural theories better explains fisher responses. This section used categorized interview responses based on their agreement, or not, with assumed responses if a particular behavioural theory were compatible. The results indicate that four of the five theories are most compatible with responses for at least one fisher, but that the theory of planned behaviour is the most consistent with the data overall, not rational actor theory. Specifically, fishers seem concerned with behavioural control as well as some non-catch related characteristics of the fishery, such as collective action and sustainability. The second hypothesis is that prospect theory is more compatible with current fishing behaviours than rational actor theory. Prospect theory states that people prefer more reliable outcomes, even if slightly less profitable, than outcomes which are more profitable on average, but also more variable. This section used catch data, and changes in relative use of different fishing methods to address this hypothesis. This hypothesis is confirmed for some aspects of fishery data, but not all. Fishers prefer methods which are more reliable and these methods are increasing in relative use. However, neither catch value nor reliability increases fishers’ opinions of their fishing method, but fisher characteristics which increase options do. This again indicates that behavioural control is important in determining fishers’ attitudes towards fishing. The third question addresses the social system within the fishery. It investigates whether fishing in Pemba Bay is a chosen profession or a livelihood of desperation from the poorest individuals. The study hypothesizes that fishers are as well-off as their non-fishing neighbours, and fishers who use more reliable or profitable methods are better off than those using less reliable/profitable methods and, as such, are more committed to fishing as a way of life. This section used fisher interview responses and household surveys to compare subjective and material wellbeing of fishers and non-fishers around Pemba Bay. The first part of the hypothesis is partly supported. Fishers using most methods have material standards of living comparable to non-fishers. However, they report lower subjective well-beings. Most measures of wellbeing are not affected by the reliability or profitability of the fishing method used, which does not support the second part of the hypothesis. Additionally, fishers using more profitable or reliable methods do not indicate more commitment to fishing as a way of life. The fourth and final section investigates the marine ecosystem. Based on conversations with fishers and local researchers, it is assumed that the Pemba fishery is overexploited. As such, the study hypothesizes that marine biomass, individual size of marine species, and functional diversity are lower in Pemba Bay than in other sites around Northern Mozambique, Vamizi Island, Situ Island, and Nuarro, due to high fishing pressure, and that direct removal of species by fishing has a dominant effect. This final section used baited remote underwater videos (BRUVs) to compare species composition and indices of abundance from the different locations. Again, there is support for part of this hypothesis. Marine species biomass and sizes are lower in Pemba Bay than other sites in Northern Mozambique; however, functional diversity is not different. In these data, changes in biomass and size are not correlated with amount of catch, so direct removal by fishing may not be the dominant source of change in the Pemba fishery. Together, these data indicate that the Pemba fishery may be unsustainable based on social and ecological indications. The importance of behavioural control in understanding fishing decisions indicates that any interventions to mitigate problems in the fishery will need to work with fishers to increase empowerment and allow experimentation to find locally relevant solutions to problems.