The Northern Mozambique Channel (NMC) is a tropical area of ~ 1 million km2 where pelagic fisheries supply proteins to more than 9 million people living in Comoros, Mayotte, and along the coasts of Mozambique, Tanzania and Madagascar. Although uncertain, statistics suggest that about 20,000 mt of tropical tuna and other pelagic fish are annually caught by artisanal fisheries in the area. The NMC is also a major seasonal fishing ground for high-seas fleets that export an annual average catch of more than 20,000 mt to tuna can and sashimi markets of high-income countries for a value estimated to be more than 100 million USD. The fisheries productivity of the NMC appears to be highly variable in relation to strong annual and seasonal variability in oceanographic conditions. Our review shows that the NMC is a key feeding area for tropical tunas and a major spawning area for skipjack tuna thanks to warm waters and strong mesoscale activity that results in the enrichment of surface waters and efficient energy transfers enabled by short food chains. Projections of climate models under future warming scenarios predict some strong changes in the oceanographic conditions of the NMC which has already experienced substantial warming over the last decades. Changes in the pelagic ecosystem of the NMC could have dramatic consequences on the coastal populations that are expected to increase towards 100 million people by 2100. Improving monitoring systems and collecting information on the socio-economics of coastal fisheries is crucial to assess the dependence of NMC populations on tuna resources and empower the countries to more involvement in the management of tuna stocks.

中文翻译：

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莫桑比克北部海峡对印度洋热带金枪鱼渔业的关键作用

莫桑比克北部海峡 (NMC) 是一个约 100 万平方公里的热带地区，远洋渔业为生活在科摩罗、马约特岛以及莫桑比克、坦桑尼亚和马达加斯加沿岸的超过 900 万人提供蛋白质。尽管不确定，但统计数据表明，该地区的手工渔业每年捕获约 20,000 公吨热带金枪鱼和其他中上层鱼类。NMC 也是公海船队的主要季节性渔场，每年平均向高收入国家的金枪鱼罐头和生鱼片市场出口超过 20,000 公吨的渔获量，估计价值超过 1 亿美元。NMC 的渔业生产力似乎与海洋条件的强烈年度和季节性变化有关。我们的审查表明，NMC 是热带金枪鱼的关键觅食区和鲣鱼的主要产卵区，这要归功于温暖的海水和强烈的中尺度活动，导致地表水的富集和短食物链实现的高效能量转移。未来变暖情景下的气候模型预测预测了 NMC 的海洋条件将发生一些强烈变化，NMC 在过去几十年中已经经历了大幅变暖。NMC 远洋生态系统的变化可能对沿海人口产生巨大影响，预计到 2100 年，这些人口将增加到 1 亿。