The Mozambique Channel region in East Africa has diverse marine ecosystems and serves as a migratory corridor for economically important species. Local and foreign industrial fisheries operate in the Mozambique Channel, but local small-scale fisheries are the crucially important fisheries that provide food-security, livelihoods and economic opportunities for rural coastal communities. This study reconstructed and investigated trends in the fishing effort and catch per unit effort (CPUE) of small-scale marine fisheries in the four Exclusive Economic Zones (EEZs) that constitute the Mozambique Channel, i.e., Union of Comoros, Madagascar, Mayotte and Mozambique, from 1950 to 2016. Effective fishing effort for small-scale fisheries in the form of fishing capacity in kWdays (i.e., kilowatt days) was derived using the number, length, motorization (engine power) by fishing vessels as well as an approximate human-powered equivalent for shore-based fishers without vessels, as well as days of fishing per year. Effective small-scale fishing effort in the Mozambique Channel increased by nearly 60 times from just over 386,000 kWdays in 1950 to over 23 million kWdays in 2016. Correspondingly, the overall small-scale CPUE, based on previously and independently reconstructed catch data declined by 91% in the region as a whole, from just under 175 kg·kWday-1 in the early 1950s to just over 15 kg·kWday-1 in recent years. All four countries showed strongest declines in the small-scale CPUE in the earlier decades, driven by motorization and growth in vessel numbers impacting effective fishing effort. Increased motorization combined with a substantial growth in overall vessel numbers were the drivers of the increasing fishing effort and decreasing CPUE, and clearly suggest that continuing to increase the fishing capacity of small-scale fisheries in the absence of effective and restrictive management actions may exacerbate overexploitation risk.

中文翻译：

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莫桑比克海峡地区小规模渔业的捕捞努力量和相关单位捕捞量：1950-2016

东非的莫桑比克海峡地区拥有多样化的海洋生态系统，是重要经济物种的迁徙走廊。当地和外国工业渔业在莫桑比克海峡开展业务，但当地小规模渔业是至关重要的渔业，为沿海农村社区提供粮食安全、生计和经济机会。本研究重建并调查了构成莫桑比克海峡的四个专属经济区 (EEZ)，即科摩罗联盟、马达加斯加、马约特岛和莫桑比克的小规模海洋渔业捕捞努力量和单位努力量 (CPUE) 的捕捞量趋势，从 1950 年到 2016 年。 以千瓦日（即千瓦日）为单位的捕捞能力形式的小型渔业有效捕捞努力量是使用数量、长度、渔船的机动化（发动机动力）以及无船的岸上渔民的近似人力等价物，以及每年的捕鱼天数。莫桑比克海峡的有效小规模捕捞努力量增加了近 60 倍，从 1950 年的略多于 386,000 千瓦日增加到 2016 年的超过 2300 万千瓦日。相应地，基于先前和独立重建的渔获量数据的整体小规模 CPUE 下降了 91 % 在整个地区，从 1950 年代初期的略低于 175 kg·kWday-1 到近年来略高于 15 kg·kWday-1。由于机动化和影响有效捕捞努力的船舶数量增长，所有四个国家在前几十年的小规模 CPUE 下降幅度最大。