雅砻江锦屏减水河段产漂流性卵鱼类早期资源及变化 |
Status and Evolution of Early-stage Resources of Fishes with Drifting Eggs in the Water-reduction Reach of Yalong River Below Jinping Waterpower Station Stage II |
投稿时间:2024-05-12 修订日期:2024-06-11 |
DOI:10.15928/j.1674-3075.202405120184 |
中文关键词:漂流性卵 早期资源 梯级开发 减水河段 累积影响 雅砻江 |
英文关键词:drifting eggs early-stage fish resources cascaded power stations water-reducing reach cumulative effect Yalong River |
基金项目:水利部三峡工程管理司三峡后续工作项目(12620200600020J005);雅砻江流域水电开发有限公司资助项目(0023-19ZB0139)。 |
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中文摘要: |
分析雅砻江两河口和杨房沟水电站投产运行初期锦屏减水河段产漂流性卵鱼类早期资源现状,可为雅砻江中下游梯级水电开发的环境影响研究提供数据支撑。2022年5-7月在雅砻江干流锦屏二级减水河段凉山州冕宁县里庄断面设置采样点利用半圆弶网采集鱼类卵苗,同时测量网口流速、水温等环境因子,并结合径流量数据推断产卵场位置及规模。结果采集到鱼类卵苗12种,其中产漂流性卵鱼类4种,分别是中华金沙鳅、犁头鳅、长薄鳅和中华沙鳅。估算调查期间锦屏减水河段产漂流性卵径流量约为1019.07万粒,在5月下旬水温达到16℃以上开始繁殖,7月中上旬水温17℃以上达到繁殖高峰,较大规模的产卵场主要分布在九龙河口以下和爱、南河-青纳和里庄等3个江段。与2013年及2019-2020年调查相比,该河段均以中华金沙鳅和犁头鳅为主要产卵种类,鱼卵密度低于2013年,高于2019-2020年,近年来繁殖规模总体呈现稳中有升的趋势,繁殖高峰期有所推迟。由于流水环境的存在,锦屏减水河段保留有雅砻江下游规模最大的产漂流性卵鱼类产卵场,建议继续加强河段水温观测、评估分层取水效果、优化生态调度方案以保护雅砻江下游鱼类资源。 |
英文摘要: |
In this study, we analyzed the current status of early-stage resources of fish species that spawn drifting eggs in the water-reduction reach of Yalong River downstream of Jinping waterpower station stage II during the initial operation of the Lianghekou and Yangfanggou hydropower stations, and explored trends in early-stage resources. We aimed to provide data support for the study of cumulative environmental impacts of cascaded hydropower development in the middle and lower reaches of the Yalong River. The study was based on the early-stage fish resource survey conducted at a Lizhuang transect from May 26 to July 24 in 2022. The quantity of the eggs was recorded, egg development was monitored, and water temperature and velocity were measured. The location of spawning grounds and the spawning scales were then deduced. A total of 12 fish species were collected during the investigation, and 4 fish species with drifting eggs were identified, including Jinshaia sinensis, Lepturichthys fimbriata, Leptobotia elongate and Botia superciliaris. Among them, J. sinensis was the absolute dominant species, with eggs collected from J. sinensis accounting for 89.62% of the total. It is estimated that the recruitment of pelagic eggs in the reduced water reach of Jinping waterpower station stage II was 10.19 million throughout the investigation. Fish spawning began when the water temperature reached 16℃ in late May, and peaked when the water temperature exceeded 17℃ in early-mid July. The largest spawning scales were produced by J. sinensis and L. fimbriata, with egg recruitments of 9.06 million and 1.10 million, respectively. However, the spawning behavior of migratory river fishes like L. elongate has occurred only sporadically in recent years, indicating that these species have maintained only a small breeding population. There were three larger spawning grounds of fish species with drifting eggs, mainly distributed in the following three river sections: below the Jiulong River confluence, the Ainan River-Qingna River, and Lizhuang River. The composition of fish species with drifting fish eggs was similar to historical surveys, and J. sinensis and L. fimbriata were the primary spawning species during their spawning periods. Fish egg density was lower than that in 2013, but higher than the survey results of 2019—2020, presenting a steady increase in breeding. Compared with previous results, the peak period of fish spawning drifting eggs has been delayed until early and middle July, likely due to low temperature discharges occurring upstream. In conclusion, although affected by human activities, the water-reduced reach of Jinping waterpower station stage II still has the largest spawning ground for fish laying drifting eggs in the lower reaches of the Yalong River. Based on the results of this study, we recommend closer monitoring of water temperature, evaluating the effect of stratified water intake, and optimizing ecological operation to protect fish resources in the lower reaches of Yalong River. |
汪鄂洲,刘健华,徐 丹,黄 敏,张 棋,杨 钟,董微微,曾 昌,邵 科.2024.雅砻江锦屏减水河段产漂流性卵鱼类早期资源及变化[J].水生态学杂志,45(5):97-105. |
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