ABSTRACT Mesoscale eddies are important ocean phenomena that enhance biological productivity by mixing of water column and influence fishery catches, especially in stratified seas such as Bay of Bengal and Andaman Sea. The current study was conducted around the Andaman and Nicobar Islands (ANI), India located in the Eastern Indian Ocean. The study tested the feasibility of targeted fishing in eddies, by characterizing the mesoscale eddies in the region, towards developing operational altimetry-based fishery advisories for the fishers. We analysed fish catch data from 15,370 commercial fishing trips from the Islands using five fishing gears during 2014–17 spatially vis-à-vis the eddies delineated from Maps of Sea Level Anomaly (M-SLA). We show that 5-24% of the routine commercial catches occurred in eddies, fishery catches are positively influenced by different eddy zones and the fish catch using different fishing gear are significantly higher in some of the eddy zones. We generated experimental advisories showing locations of eddies and their zones, identified using Near Real-Time M-SLA data and guided the commercial fishers for targeted fishing in eddies. The fish Catch Per Unit Effort (CPUE) from the experimental fishing within the eddy zones was significantly (p < 0.01) higher than that from the traditional fishing grounds in the non-eddy areas. The spatio-temporal analysis of eddies around ANI during 2009–16 showed the occurrence of higher number of anticyclonic eddies, majority of which move westward and have a lifespan of less than 2 weeks and amplitude less than 4 cm. In the current study, the areas around ANI with frequent eddy occurrence and eddy density have been identified, which could aid in increasing the fishing intensity by targeting the pelagic fishes, using longlines, gillnets and ringnets. Thus, we show the possibility of using eddy fishing advisories generated from altimeter data, for augmenting the currently operational Potential Fishing Zone (PFZ) advisories that are generated using optical/thermal remote sensing data and disseminated to the coastal fishers in India. This will be helpful especially for the regions with and during periods of persistent cloud cover.

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在中尺度海洋涡流中进行定向捕捞的可行性：来自印度安达曼和尼科巴群岛商业渔场的研究

摘要 中尺度涡旋是重要的海洋现象，它通过混合水体来提高生物生产力并影响渔业捕捞量，特别是在孟加拉湾和安达曼海等分层海域。目前的研究是在位于东印度洋的印度安达曼和尼科巴群岛 (ANI) 周围进行的。该研究通过表征该地区的中尺度涡流，测试了在涡流中进行有针对性的捕捞的可行性，以便为渔民制定基于测高的业务渔业咨询。我们在 2014-17 年期间使用五种渔具分析了来自群岛的 15,370 次商业捕鱼旅行的捕鱼数据，相对于海平面异常地图 (M-SLA) 描绘的漩涡在空间上。我们表明 5-24% 的常规商业捕捞发生在涡流中，渔业捕捞量受到不同涡流区的积极影响，在某些涡流区，使用不同渔具的渔获量明显更高。我们生成了显示涡流位置及其区域的实验建议，使用近实时 M-SLA 数据进行识别，并指导商业渔民在涡流中进行有针对性的捕鱼。涡流区内实验捕捞的单位努力渔获量（CPUE）显着高于非涡流区传统渔场（p < 0.01）。2009-16 年 ANI 周围涡旋的时空分析表明，反气旋涡旋出现的数量较多，其中大部分向西移动，寿命小于 2 周，振幅小于 4 cm。在目前的研究中，已经确定了频繁发生涡流和涡流密度的 ANI 周围区域，这可以通过使用延绳钓、刺网和环网瞄准远洋鱼类来帮助增加捕捞强度。因此，我们展示了使用从高度计数据生成的涡流捕鱼建议的可能性，以增加使用光学/热遥感数据生成并传播给印度沿海渔民的当前可操作的潜在捕鱼区 (PFZ) 建议。这对于有持续云覆盖和持续云覆盖期间的地区尤其有用。用于增加使用光学/热遥感数据生成并传播给印度沿海渔民的当前运行的潜在捕鱼区 (PFZ) 咨询。这对于有持续云覆盖和持续云覆盖期间的地区尤其有用。用于增加使用光学/热遥感数据生成并传播给印度沿海渔民的当前运行的潜在捕鱼区 (PFZ) 咨询。这对于有持续云覆盖和持续云覆盖期间的地区尤其有用。