DataSheet_1_Overfishing Increases the Carbon Footprint of Seafood Production From Small-Scale Fisheries.csv

Small-scale fisheries (SSFs) and the foods they produce are extremely important, contributing 25–50% of global seafood landed for direct consumption. In some cases, SSFs provide seafoods with an exceptionally low carbon footprint, but like all food, it is important to understand the factors that regulate that footprint in the face of increasing demand and a worsening climate-ecological crisis. We utilize long-term fisheries monitoring data from Northwest Mexico to generate novel stock assessments and, subsequently, test the relationship between underlying fishery biomass and fuel intensity observed among several motorized SSFs. Using fuel data from over 4,000 individual fishing trips, in combination with estimated biomass data for 19 regional stocks, we show that the fuel footprint per kilogram of seafood increases sharply as the stock’s underlying annual biomass (B) falls below its estimated biomass at Maximum Sustainable Yield (BMSY). We find an inverse relationship between B/BMSY and fuel intensity using a test for simple correlation between the two (r= -0.44), a linear regression analysis (R2adj. = 0.17), and a mixed-effects model with gear type, year, and genus modelled as random effects. These results indicate that efforts to end overfishing, rebuild fishery stocks, and/or minimize intensive fishing practices will help to decrease the carbon emissions generated by motorized wild-catch fishing. We anticipate that this study will contribute an important “missing link” to discussions on how best to secure climate-resilient fisheries and, ideally, help SSF stakeholders garner recognition and support for SSFs in this context.

小型渔业（Small-scale Fisheries, SSFs）及其所产出的水产品极为重要，贡献了全球上岸供直接消费的海捕水产品总量的25%至50%。在部分场景中，小型渔业所提供的水产品拥有极低的碳足迹（carbon footprint），但与所有食品品类一样，在需求持续增长与气候生态危机日益严峻的背景下，明晰调控该碳足迹的相关因素至关重要。本研究依托墨西哥西北部的长期渔业监测数据，开展了全新的渔业资源评估，并以此为基础，检验了若干机动化小型渔业中，渔业种群生物量与燃料强度（fuel intensity）之间的关联关系。研究整合了逾4000次单次捕捞航程的燃料数据，以及19个区域渔业种群的估算生物量数据，结果显示，当渔业种群的年度生物量（B）低于其最大可持续产量对应的估算生物量（Maximum Sustainable Yield, BMSY）时，每千克水产品的燃料足迹（fuel footprint）会急剧升高。本研究通过两项变量间的简单相关性检验（相关系数r=-0.44）、线性回归分析（调整后决定系数R²_adj.=0.17），以及以作业渔具类型、年份与属类作为随机效应的混合效应模型，证实了B/BMSY与燃料强度之间存在负相关关系。研究结果表明，终止过度捕捞、恢复渔业种群规模，或限制集约化捕捞行为的相关举措，均有助于降低机动化野生捕捞渔业（wild-catch fishing）所产生的碳排放。本研究有望为探讨如何最优构建气候韧性渔业的相关讨论补上关键的"缺失环节"，并有望助力小型渔业的利益相关方在此背景下争取对小型渔业的认可与支持。