Energy performance of wild-capture marine fisheries at global, regional, and local scales

Modern wild-capture marine fisheries are underpinned by energy derived from fossil fuels. This energy is required for vessel propulsion and gear operation, onboard processing, freezing and refrigeration, and producing electricity for ancillary services. Fuel use is the primary driver of greenhouse gas (GHG) emissions from marine fisheries, and the second highest cost to fishers globally after labour. Fuel consumption has received increased attention from industry, consumers, governments, and environmental organizations in response to higher and more unpredictable energy prices and the need to reduce GHG emissions to mitigate climate change. A large and growing amount of research has been undertaken since the beginning of the 21st century to measure, characterize, and reduce energy use and GHG emissions in fishing fleets. This thesis provides an overview of the magnitude of fuel consumption in marine wild-capture fisheries, assesses how and why fuel consumption and GHG emissions vary between vessels, fleets, and national industries, and discusses the environmental and economic implications of energy use in fisheries at global, regional, and local scales. The global-scale research here involved the synthesis and analysis of data pertaining to fuel use in fisheries. Data from all available primary and secondary sources were compiled in a global fisheries and energy use database (FEUD). Observed rates of fuel inputs to global fisheries were characterized by target species, primary gear type, and region. Fuel use rates were then used as a proxy to estimate GHG emissions from national and global fishing fleets, assess the relative emissions from different sectors of the global fishing fleet, and track emissions from the industry from 1990 to 2011. World fisheries in 2011 consumed 40 billion litres of fuel and emitted 168 million tonnes of carbon dioxide-equivalent GHGs to the atmosphere. Energy performance varied between fisheries by three orders of magnitude, with crustacean fisheries consuming vastly more fuel than fisheries targeting small pelagic forage fish. Regional-scale research applied cost and revenue data to estimate the fuel use intensity (FUI) of a range of Australian fisheries and compare environmental (emissions) and economic (costs) roles of fuel use. Australian fisheries followed similar patterns to global fisheries, with all of the more fuel-intensive fisheries targeting rock lobsters and prawns, while the more efficient fisheries targeted small pelagics. The economic role of fuel also varied markedly, although fuel costs as a percentage of fishing revenue did not consistently correlate with consumption rates. Fuel expenditures in Australian fisheries ranged from 2% of revenue in abalone fisheries to almost 50% in some prawn fisheries, reflecting not only consumption but also product value. Importantly, some Australian fisheries were identified as having reduced their FUI in recent years: in particular, the Northern Prawn Fishery experienced dramatic improvement in energy performance following substantial management changes including a rapid reduction in number of fishing vessels. Local-scale research surveyed rock lobster fishers in several locations in Australia and New Zealand to quantify energy performance of different sectors of a single fishing industry (targeting similar species with similar gear and producing similar products), and to determine the relative role of technological, behavioural, and managerial factors in driving fuel use. Average weighted FUI of rock lobster fisheries was 1,890 L/t. Interregional comparisons showed that fuel consumption was lowest in Western Australia and New Zealand, where catch per unit effort (CPUE) was highest. The drivers of fuel use varied between single day and multiday trips‚ÄövÑvÆmanagementrelated factors, particularly CPUE, were more influential in single day trips, while technological variables played a larger role in multiday trips. This thesis demonstrates that fisheries vary markedly in fuel use and GHG emissions. Globally and regionally, fuel use largely reflects the species being targeted and the gear being used. Within fisheries, fuel use is influenced by a range of factors, and the relative effect of these factors varies between fishery. It is therefore difficult to generalize across the entire industry when assessing the economic and environmental performance of fisheries and their products in relation to energy use and GHG emissions. Many fisheries can produce low-carbon, climate-friendly sources of animal protein and should be promoted as such, while others are as intensive as high-impact ruminant production. Importantly, more efficient fisheries are not necessarily more resilient to fuel costs, and the economic impacts on these fisheries needs to be considered when discussing subsidies and carbon-pricing policies. The measurement and characterization of fuel use contributes to our understanding of both the environmental sustainability of fisheries and the economic resilience of fisheries to rising and volatile energy prices and carbon-related policies. Energy resource use and climate change will be defining challenges of the 21st century, and the measurement, characterization, and improvement of energy performance in fishing fleets is required to ensure the socio-economic resilience and environmental sustainability of the industry. Incorporation of these issues into fisheries management and assessments can benefit the industry in the long-term, and help provide a growing global population with affordable, sustainable products from the ocean.