鄱阳湖极枯水位下长江江豚栖息状况分析

Habitat Analysis of Yangtze Finless Porpoises in Poyang Lake under Extremely Low Water Level

【目的】异常干旱导致的鄱阳湖极枯水位对湖区生态系统影响深远,为摸清鄱阳湖极枯水位下国家一级保护动物长江江豚(Neophocaena asiaeorientalis asiaeorientalis)的栖息状况,增强对该珍稀物种的保护,2022年9月和12月异常干旱水情下开展2次鄱阳湖长江江豚同步监测。【方法】通过水上流动目视监测法考察长江江豚栖息状况,以核密度估计法(KDE)计算长江江豚核心家域范围,并分析极枯水位下长江江豚船舶干扰、栖息岸线等状况。【结果】极枯水位下,鄱阳湖长江江豚呈现区域聚集分布,核心家域主要为屏峰、火焰山、老爷庙—渚溪河口—小矶山—松门山-瓢头、瓢山—棠荫—龙口水域;江豚主要栖息在泥质岸(44.5%)、沙洲(23.1%)和沙质岸(18.5%)等天然水域;船舶主要分布在长江江西段和湖口-吴城水域,船舶数量与长江江豚数量具有显著负相关性(P=0.02)。【结论】极枯水位下,长江江豚核心家域主要分布在船舶密度低、人类干扰少以及以泥质岸为主的天然岸线水域,船舶分布对长江江豚栖息地选择具有一定的影响。水域空间的减少,使长江江豚受搁浅、被困、饵料短缺、船舶干扰以及人类活动影响等的风险增加。应根据长江江豚核心家域范围制定特殊水情下的重点巡护保护区域,关注长江江豚高密度分布水域的饵料资源状况,适时开展增殖放流;依据长江江豚分布水域、船舶密度以及水域空间等科学实施船舶限航限速管控;开展特殊水情下的长江江豚保护宣传,增设极枯水位禁钓区,减少人类干扰。

[Objective]The extremely low water level of Poyang Lake caused by abnormal drought has a profound impact on the ecosystem of the lake area.In order to understand the habitat status of the Yangtze finless porpoise,a national first-class protected animal under the extremely low water level of Poyang Lake,and to enhance the protection of this rare species,two simultaneous monitorings of the Yangtze finless porpoise in Poyang Lake were conducted under abnormal drought conditions in 2022.[Method]The living conditions of YFPs was investigated by water flow visual monitoring method,the core home range of YFPs was calculated by kernel density estimation(KDE).The status of the Yangtze finless porpoise’s ship interference and habitat shoreline under extremely low water level was analyzed[.Result]The YFPs in Poyang Lake under the extremely low water level showed regional aggregation and distribution,and the core home range include the water area of Pingfeng,Huoyan Mountain,Laoye Temple,Zhuxihekou,Xiaoji Mountain,Songmeng Mountain,Piaotou,Duchang,Piaoshan,Tangyin and Longkou in the main lake area.The YFPs mainly inhabits natural waters such as muddy banks(44.5%),sandbars(23.1%),and sandy banks(18.5%).Ships were mainly distributed in the Jiangxi section of the Yangtze River and the Hukou-Wucheng waters.There was a significant negative correlation between the number of ships and the number of Yangtze finless porpoises(P=0.02).There is a significant negative correlation between the number of ships and the number of YFPs(P=0.02).[Conclusion]The core home range of YFPs is mainly distributed in natural shoreline waters with low ship density,low human interference,and mainly muddy banks.Ships distribution has an impact on the habitat selection of the YFPs.The reduction of water space increases the risk of YFPs being stranded,trapped,food shortage,ship interference,and human activity.Key patrol and protection areas under special water conditions should be established based on the core home range of YFPs,and attention should be paid to the bait resources in the high-density distribution water area of YFPs,and timely proliferation and release should be implemented.According to the Yangtze River finless porpoise distribution waters,ship density and water space,the ship’s speed limit control should be scientifically implemented.The protection publicity of Yangtze finless porpoise under special water conditions should be promoted.,Fishing zones at extremely low water levels should be established to reduce human interference.