| dc.description.abstract | Growing evidence suggests that climate change is altering storm frequency and intensity over the world’s oceans. Uniquely among fisheries climate risks, changing storminess poses risks over short temporal scales and direct social risks to fishers. However, little is known about fisher decision-making in the context of short-term weather-related risks and consequently their vulnerability to climate change. Improving our understanding of this climate threat is critical because fish provide livelihoods, food security, and cultural identity to billions of people globally. It is estimated that 38 million people directly harvest fish; 12% of the population (approximately 900 million) make their livelihoods in the fisheries supply chain; and 3.1 billion people rely on fish for 20% of their animal protein (FAO, 2016). The United Kingdom commercial marine capture fishery, particularly the fleet in Cornwall in southwest England, provides a useful case example for changing storminess and fisheries research. The UK is exposed to the North Atlantic storm track and the fishery is highly varied in terms of target species, fishing methods, and vessel characteristics, thereby offering wider insights at a global scale. By focusing on fishers’ short-term behavioural responses to storm-related weather conditions, this thesis seeks to improve understanding of fisheries climate vulnerability. The thesis findings can help inform the inclusion of changing storminess in fisheries climate vulnerability assessments and adaptation action. In this thesis I draw on qualitative and quantitative research approaches to provide global, UK-wide and local insights relating to the risk posed by changing storminess to marine capture fisheries. First, a global review of changing storminess and the ecological and social effects of storms on fisheries was carried out to inform a research roadmap for this novel field. Second, skippers in Newlyn, Cornwall were interviewed to provide a rich, qualitative description of how weather conditions feature in fishers’ short-term fishing decisions. Third, a stated choice experiment was carried out with 80 skippers fishing in Cornwall to empirically estimate their preferences for weather conditions, fish price and catch, and to identify how they trade off physical risk and economic rewards in their daily trip decisions. Fourth, a novel fine spatial-temporal resolution dataset describing a decade of UK fisheries landings and weather conditions was analysed to describe the influence of weather conditions on fisheries productivity for vessels choosing to be at sea. Finally, the extent to which Newlyn skippers manage physical risk was assessed using semi-structured interview data by comparing their approach to the ISO 31000 risk management process. The global review of changing storminess and capture fisheries found this field is in its infancy. Globally, the evidence suggests that the ecological and socio-economic impacts of storms on fisheries are extensive and potentially catastrophic. Existing research suggests that changing storminess is spatially heterogeneous within and between ocean basins. A research roadmap was proposed that included improving climate modelling of storms, exploring fishers’ behavioural response to storms, identifying the mechanisms by which storms affect fish and their habitat, investigating social-ecological linkages, and developing adaptation actions and assessments of the fisheries vulnerability to changing storminess. Semi-structured interviews revealed that a complex interaction of meteorological and oceanographic variables affect the elements of fishers’ trade-offs. Newlyn skippers were found to have a binary perspective on safety. When skippers judged conditions to be unsafe, they generally chose not to be at sea. When conditions were considered safe, fishers were found to trade off physical risk, discomfort, and economic reward in their short-term fishing decisions. Fishers’ trade-offs were influenced by a number of individual fisher differences and social processes, such as economic need and fear of missing out. Working with crew was also important, due to a desire to protect their crew’s safety and comfort, but also because of the effect of crew capability on physical risk. Fishing methods and vessel characteristics were found to influence the effect of adverse weather on physical risk and trip profitability. For instance, purse seines were described as highly sensitive to large waves due to reduced vessel stability during net hauling, and bottom trawl skippers explained that larger waves reduce their catch due to reduced gear efficacy. The stated choice experiment revealed that fishers operating in Cornwall have non-linear preferences for weather conditions. They initially preferred higher wind speed and wave height, before their preferences fell at an accelerating rate. Fishing gear, vessel length, presence of crew, vessel ownership, age, recent fishing success and reliance on fishing income all influenced the skippers’ decisions to go to sea. Skippers of larger boats and those that owned their boat were more likely to go to sea in worse weather conditions than those of smaller boats or those that did not own their boat. Skippers with greater economic need were more likely to take greater physical risk. Trade-offs also differed by fishing methods. Hand lining skippers were less averse to wind speed and wave height than those using other gears, purse seine skippers preferred small waves more than skippers using other gear types, but their aversion to wave height fell more rapidly. Analysis of the novel national scale landings and weather data revealed that landings varied with wind speed and wave height in non-linear ways, differentiated by gear type. Landings either increased with, or were unaffected by, increasing wind speed and wave height with the exception of pots and traps, for which landings decreased with both weather variables. Midwater trawls and gillnets and entangling nets showed the most biologically significant increase in landings as wind speed and wave height increased. For the most economically important UK fishing method, bottom trawls, the effect of weather variables on landings on varied slightly with the smallest boats seeing a greater fall in landing at extreme weather levels and the second largest vessels experiencing no reduction in catch. Mean daily landings did not always increase with vessel size within gear type. For instance, the largest vessel length category for pots and traps, seines, and hooks and lines did not have the largest mean catch. Comparing Newlyn skippers’ approach to risk management process theory demonstrated that they informally carried out each step of the ISO 31000 risk management process. As such, they were determined to be experts at managing risk. The skippers described their risk context, how they identify hazards, the way that they analyse the likelihood and consequence of the risks, evaluating these risks against their context, before treating the risk, predominantly using risk avoidance, risk reduction, and risk acceptance strategies. The analysis of risk likelihood of at-sea hazards using weather data, including digital forecasts, real time data, visual observation, and testing the conditions was central to their management of risk. By taking a bottom-up approach, this thesis has revealed the importance of individual fisher behaviour in climate vulnerability. The findings provide insights for the concept of fishers’ sensitivity to climate risks, a key tenet in the concept of climate vulnerability, because fishers choose the risks they are sensitive to through the way they make trade-offs in their short-term decisions. The effect of weather conditions on landings indicates that UK skippers who take the physical risk of going to sea will not be sensitive to reduced catches, unless they use pots and traps or bottom trawls in the most extreme conditions. This provides insights into fishers’ trip catch expectations, and therefore how economic reward features in their decision trade-offs. The expertise shown by skippers in their approach to risk management may make them safer by mitigating the physical risks they face from storms when at sea and reducing the likelihood of accepting greater risk than intended. The findings in this thesis have implications for the design of fisheries vulnerability assessments. Designers of fisheries vulnerability assessments should seek to include exposure, sensitivity, and adaptive capacity to changing storminess, with particular attention to individual heterogeneity in physical and economic risk sensitivity. Individual fisher heterogeneity should also be reflected in the way that changing storminess adaption policies, such as climate risk insurance instruments, are designed. The new knowledge presented in this thesis represents the first focused research efforts in the field of changing storminess and fisheries. It is hoped that by informing vulnerability assessments and adaptation actions, this thesis will contribute to improving the wellbeing of fishers and coastal communities in the UK and further afield as the climate changes. | en_GB |
