Cetaceans in the Southern Indian Ocean 2004

Original provider:
Central Marine Fisheries Research Institute

Dataset credits:
Dr. Pallipuram Jayasankar, Central Marine Fisheries Research Institute

Abstract:
A multi-disciplinary and multi-institutional pilot expedition was organized by the National Centre for Antarctic and Ocean Research (NCAOR) to the ice-free areas of the Western Indian Ocean sector of the Southern Ocean onboard ORV Sagar Kanya during the austral summer of 2004 (January-March). This survey, conducted by the Central Marine Fisheries Research Institute (CMFRI), is the first Indian attempt to survey for cetacean diversity in the Southern Ocean. The ultimate objective is to determine distribution, relative abundance, migration patterns and critical habitat parameters. 68% of a total of 13 sightings (22 individuals) were positively identified and species observed included Antarctic minke whales (<i>Balaenoptera bonaerensis</i>), fin whales (<i>B. physalus</i>), sei whales (<i>B. borealis</i>) and blue whales (<i>B. musculus</i>). The blue whales were not identified to the sub-species level. The highest concentration of cetaceans was between 35° and 37°S (along 45°E) and between 48° and 53°S (along 45°E). Relatively small numbers of cetaceans were observed during the present cruise, possibly because most of the cetacean sighting effort was made during inclement sea conditions. Results on the sighting characteristics and occurrence patterns of the cetaceans in relation to the region and hydrographical parameters are discussed briefly <i>vis a vis</i> published information from the Southern Ocean.

原始提供方：中央海洋渔业研究所（Central Marine Fisheries Research Institute）
数据集贡献者：帕利普拉姆·贾亚桑卡尔博士，中央海洋渔业研究所（Central Marine Fisheries Research Institute）
摘要：
2004年南半球夏季（1—3月），国家南极与海洋研究中心（National Centre for Antarctic and Ocean Research, NCAOR）依托“萨加尔·坎亚号”海洋考察船（ORV Sagar Kanya），组织多学科、多机构的试点考察航次，前往南大洋西印度洋海域的无冰区域开展调查。本次由中央海洋渔业研究所（CMFRI）主导的调查，是印度首次针对南大洋鲸类多样性开展的考察尝试。本研究的最终目标为明确鲸类的分布格局、相对丰度、迁徙模式及关键栖息地参数。
在总计13次目击记录（涉及22头个体）中，68%得到了确证鉴定；本次观测到的鲸类物种包括南极小须鲸（*Balaenoptera bonaerensis*）、长须鲸（*B. physalus*）、塞鲸（*B. borealis*）及蓝鲸（*B. musculus*）。蓝鲸未被鉴定至亚种层级。
鲸类的最高聚集区域位于南纬35°至37°（沿东经45°）以及南纬48°至53°（沿东经45°）海域。本次航次观测到的鲸类数量相对较少，这可能是因为多数鲸类目击工作均在恶劣海况下开展。
本文简要比照南大洋已发表的相关研究资料，对鲸类目击特征、该区域鲸类出现模式与水文参数的关联研究结果进行了讨论。