DataSheet_1_Reducing the Fuel Use Intensity of Fisheries: Through Efficient Fishing Techniques and Recovered Fish Stocks.csv

Understanding the drivers of greenhouse gas emissions in food production systems is becoming urgent. For wild capture fisheries, fuel use during the fishing phase generally dominates emissions and is highly variable between fisheries. Fuel use is also essential for the economy of the fisheries, but fuel-intensive fisheries can still be profitable due to fuel subsidies, in particular, if the target species is of high value. Developing an innovative bottom-up approach based on detailed catch and spatial fishing effort data, in the absence of direct fuel data, we analysed the fuel use intensity (fuel use per kg landed) and economic efficiency (landing value per litre fuel used) of Danish capture fisheries for the period 2005-2019. An overall decline in fishing effort did not significantly affect the overall fuel use intensity and efficiency, which was stable for most of the fleet segments and marine species. Robust differences in fuel use intensity among individual fisheries, reflected differential spatial accessibility and vulnerability of target species to fishing. In addition, different fishing techniques targeting the same set of species showed differences in fuel use per unit landed. Danish seining and gillnets had a lower fuel use intensity and higher economic efficiency than demersal trawling; and purse seining than pelagic trawling. The variability between stocks and fleets also indicates that there is generally potential for improvement in overall efficiency from improved stock status. Short-term management actions to promote the best available fuel-efficient fishing techniques combined with additional long-term actions to secure the recovery of stocks have the potential to reduce fishery greenhouse gas emissions. Sustainable fisheries and normative environmental management are crucial to developing incentives towards reducing fuel use whenever the fishing sector industry and science work jointly at implementing solutions, as incentives for the industry to reduce fuel use are limited as long as the fishing activity is profitable.

深入探究食物生产系统中温室气体排放的驱动因素，已成为当务之急。对于野生捕捞渔业而言，在捕捞阶段燃料消耗通常占据排放的主导地位，且在不同渔业之间呈现出极大的变异性。燃料消耗对于渔业经济的繁荣亦至关重要，然而，由于燃料补贴的存在，即使是燃料消耗密集型的渔业仍能保持盈利，尤其是当目标物种具有较高的经济价值时。在缺乏直接燃料数据的情况下，我们基于详尽的捕捞量和空间捕捞强度数据，采用自下而上的创新方法，分析了2005-2019年丹麦捕捞渔业的燃料使用强度（单位捕捞量燃料消耗）和经济效率（单位燃料使用的捕捞价值）。整体捕捞强度的下降并未显著影响整体的燃料使用强度和效率，大多数船队部门和海洋物种的效率保持稳定。个体渔业之间燃料使用强度的稳健差异反映了目标物种对捕捞的时空可接近性和易受伤害性的差异。此外，针对同一组物种的不同捕捞技术也显示出单位捕捞量燃料消耗的差异。丹麦的拖网和刺网捕捞的燃料使用强度较低，经济效率较高；而围网捕捞则优于外海拖网。股票和船队之间的变异性还表明，从改善股票状况的角度来看，整体效率的提升具有普遍的潜力。短期管理措施旨在推广最有效的燃料节约型捕捞技术，并结合长期措施以确保鱼群的恢复，这些措施有望减少渔业温室气体排放。可持续渔业和规范性环境管理对于构建减少燃料使用的激励机制至关重要，当捕捞行业和科学共同致力于实施解决方案时，只要捕捞活动保持盈利，行业减少燃料使用的激励措施就会受到限制。