长江河口区江豚种群调查

Survey on Population Size of Finless Porpoise( Neophocaena asiaeorientalis) in the Estuary of Yangtze River

为弄清长江河口区江豚（ Neophocaena asiaeorientalis ）种群数量和分布情况，于2012年6月8-11日和2012年9月12-19日对这一水域作了2次较大覆盖面的目视考察和9次遗骸搜寻。6月的考察目击到江豚5群8头，9月的考察未目击江豚个体。依据样带法估算，长江河口水域6月份的江豚种群数量约为61头。全年共获得7头江豚遗骸，并搜集到其他5例死亡信息。对其中5头外表完整、特征保留良好的遗骸所作的鉴定结果显示，2头为长江亚种（ N. asiaeorientalis asiaeorientalis），3头为东亚亚种（ N. asiaeorientalis sunameri）。调查表明，崇明岛西端和青草沙附近水域是长江亚种活动的热点水域，可作为重点监护区域。

To clarify the population size and regional distribution of finless porpoise （Neophocaena asiaeorientalis） in the estuary of Yangtze River, two surveys were performed in the water surface of 238.84 km2 in size from June 8th to llth and September 12th to 19th in 2012 respectively. Eight porpoises in five groups were witnessed in June while no animal was found in September. According to the estimation based on transect of 805 km in length, 61 individuals were estimated in June. In addition seven remains and five dead records of the porpoises were collected From the riverside of the Yangtze River in the entire year 2012. Two Yangtze finless porpoises（N, asiaeorientalls asiaeorientalis） and three East Asian finless porpoises （N. asiaeorientalis sunameri） were identified based on the external characteristics of remains which were relatively intact. The results suggest that the water areas west to Chongming Island and northwest to Changxing Island might be the core distribution regions of Yangtze finless porpoise in the estuary area.