| 李永涛,于国旭,程兆龙,左涛,牛明香,王俊.2023.长岛海域东亚江豚种群密度和分布的初步研究.动物学杂志,58(5):658-668. |
| 长岛海域东亚江豚种群密度和分布的初步研究 |
| The Population Density and Distribution of East Asian Finless Porpoise in Changdao Waters |
| 投稿时间：2022-01-17 |
| DOI：10.13859/j.cjz.202305003 |
| 中文关键词: 东亚江豚 种群数量 分布 动物保护 |
| 英文关键词:East Asian Finless Porpoise, Neophocaena asiaeorientalis sunameri Population abundance Distribution Conservation |
| 基金项目:中国海油海洋环境与生态保护公益基金会项目(No. CF-MEEC/TR/2021-12)，农业农村部政府购买服务项目(No. 125C0505)，长岛国家海洋公园管理中心单一来源采购项目(No. YHZH-2021193)； |
|
| 摘要点击次数: 45 |
| 全文下载次数: 548 |
| 中文摘要: |
| 长岛海域是黄渤海东亚江豚(Neophocaena asiaeorientalis sunameri)的热点分布区域之一。为了掌握长岛海域东亚江豚的种群密度与分布特征，2019年10月至2021年10月采用截线抽样法进行了5次东亚江豚目视考察。5次考察总航程2 421 km，共发现东亚江豚614次，1 156头次。相同月份调查种群遇见率无显著性差异(P > 0.05)，不同月份种群遇见率差异极显著(P < 0.01)，提示东亚江豚种群在该水域可能存在季节性迁移。按照考察月份对数据进行合并处理，长岛海域5月和10月东亚江豚平均种群密度为(0.56 ± 0.11)头/km2(0.46 ~ 0.68头/km2)和(3.63 ± 0.25)头/km2(3.38 ~ 3.88头/km2)，平均种群数量为(20 209 ± 202)头和(2 971 ± 681)头，这在目前已知所有东亚江豚分布区中是最高的。尽管不同季节种群数量差异显著，但东亚江豚种群在长岛海域的空间分布特征相似，砣矶岛-大钦岛西北侧和东南侧均为高密度分布区，因此建议将该水域作为核心区域重点保护。此外，我们还建议未来加强对其迁移规律及栖息地选择的研究。 |
| 英文摘要: |
| [Objectives] Understanding species distributions, and how they change in space and time, is vital in prioritising conservation or management initiatives. However, the basic ecological data of East Asian Finless Porpoise (Neophocaena asiaeorientalis sunameri) in Changdao waters, such as the distribution, population and it’s dynamic, is least known for lacking of long-term studies. [Methods] Five visual surveys of East Asian Finless Porpoise were conducted from October 2019 to October 2021 using line transect sampling method. Our study area and survey lines are shown in Fig. 1. Based on the monitoring data. we calculated the abundance, density, cluster size, encounter rate, spatial and temporal distribution of East Asian Finless Porpoise. The abundance and density analysis were estimated in Distance software and distribution characteristics were conducted in geographic information system (GIS). The remaining statistical analyses were performed utilizing the SPSS statistical analysis software. Kruskal-Wallis test and Mann-Whitney U test were used to examine variations in encounter rate and cluster size across the five surveys. Furthermore, the differences between the number of animal observations by each observer were analyzed using t-test. The statistical significance level was set at P < 0.05, with P < 0.01 indicating highly significant. Mean values for encounter rate, quantity, and density were expressed as mean ± standard deviation (Mean ± SD). [Results] In total, 614 sightings with 1 156 individuals of East Asian Finless Porpoise were recorded over a total transect length of 2 421 km (Table 1). The mean encounter rate of the East Asian Finless Porpoise during the five surveys exhibited its peak in May 2020, reaching 0.49 ± 0.14 groups/km, and reached its lowest point in October 2020, with a value of 0.13 ± 0.02 groups/km (Fig. 2). Similarly, the average group size of observed East Asian Finless Porpoise during the five surveys displayed its highest value in May 2020, recorded as 2.03 ± 0.98 ind/group, while the lowest value was observed in October 2021, measuring 1.60 ± 0.61 ind/group (Fig. 5). The Kruskal-Wallis test showed that there was no significant difference among the encounter rates of the populations surveyed in the same month (P > 0.05), however, significant difference was detected in different months (P < 0.01) (Fig. 3). The results of population density and abundance calculations for the East Asian Finless Porpoise are presented in Table 2. Within the waters of Changdao, the average population density of the East Asian Finless Porpoise in May and October was recorded as 0.56 ± 0.11 ind/km2 (0.46﹣0.68 ind/km2), and 3.63 ± 0.25 ind/km2 (3.38﹣3.88 ind/km2), respectively. Correspondingly, the average population size of the East Asian Finless Porpoise in May was 20 209 ± 202 ind, exhibiting fluctuations between 20 066 and 20 352 ind. In October, the average population size was 2 971 ± 681 ind, fluctuating between 2 195 and 3 473 ind. The spatial distribution characteristics of East Asian Finless Porpoise was similar that the northwest and southeast sides of Tuoji Island-Daqin Island were the core distribution zone, and it is recommended to focus on these two spots for conservation (Fig. 4). [Conclusion] The population density of East Asian Finless Porpoise in Changdao Waters is the highest among all known areas, and there is obvious seasonal migration. These results represent the first ever estimates for the East Asian Finless Porpoise over a wide portion of the Changdao Waters, with the potential to be useful baseline data to inform conservation. |
| 附件 |
| 查看全文 查看/发表评论 下载PDF阅读器 |
|
|
|
