Yunnan Key Laboratory of International Rivers and Transboundary Eco-security, Yunnan University, Kunming, 650091, China; Institute of International Rivers and Eco-security, Yunnan University, Kunming, 650091, China.
Kunming Dianchi and Plateau Lakes Institute, Kunming, 650228, China; Dianchi Lake Ecosystem Observation and Research Station of Yunnan Province, Kunming, 650228, China.
J Environ Manage. 2023 Oct 1;343:118160. doi: 10.1016/j.jenvman.2023.118160. Epub 2023 May 23.
The rapid decline of freshwater biodiversity caused by overfishing has led to the implementation of a series of conservation measures, including fishing bans. However, existing studies have mostly focused on the effects of fishing bans on economically important species, while impacts on freshwater macroinvertebrates in lake ecosystems have been rarely studied. This study used a before-and-after methodology to determine the short-term effects of the "ten-year fishing ban" on the macroinvertebrates of the Dianchi Lake, the largest highland freshwater lake in the upper Yangtze basin, between 2015 and 2022. Following the fishing ban, the overall macroinvertebrate species richness (median [interquartile]) across sites increased from 4 [2-6] to 5 [4-7]. The total density increased from 128 [80-272] to 212 [140-325] n/m. The median biomass increased from 0.18 [0.08-0.41] to 0.51 [0.26-2.36] g/m. In particular, the Chironomidae density in the offshore sites increased from 16.00 [0.00-32.00] to 33.30 [16.00-48.00] n/m, and the biomass increased from 0.03 [0.00-0.09] to 0.16 [0.07-0.22] g/m. Within the inshore sites, the aquatic insect density increased from 4 [1.33-15.33] to 56 [22.00-86.67] n/m. The Malacostraca density increased from 34.67 [11.67-95.33] to 110 [53.33-223.33] n/m, and the biomass increased from 0.43 [0.11-1.00] to 1.48 [0.50-2.00] g/m. Two endangered Margarya species were rediscovered at multiple sites compared to the pre-fishing ban period. A significant change in macroinvertebrate community structure across the lake was observed, which can be largely attributed to the fishing ban. The immediate increase in species richness, density, and biomass of most macroinvertebrate species suggests a combination of effects from both reduced exploitation pressure and lessened disturbances on lake habitats. The findings indicate that the fishing ban is beneficial for the recovery of most macroinvertebrate species in freshwater lakes.
过度捕捞导致淡水生物多样性迅速减少，因此实施了一系列保护措施，包括禁渔。然而，现有研究大多集中在禁渔对经济重要物种的影响上，而对湖泊生态系统中的淡水大型无脊椎动物的影响研究甚少。本研究采用前后对照的方法，于 2015 年至 2022 年期间，研究了“十年禁渔”对长江上游最大的高原淡水湖泊滇池大型无脊椎动物的短期影响。禁渔后，各站点的大型无脊椎动物物种丰富度（中位数[四分位距]）从 4[2-6]增加到 5[4-7]。总密度从 128[80-272]增加到 212[140-325]n/m。生物量中位数从 0.18[0.08-0.41]增加到 0.51[0.26-2.36]g/m。特别是离岸站点的摇蚊密度从 16.00[0.00-32.00]增加到 33.30[16.00-48.00]n/m，生物量从 0.03[0.00-0.09]增加到 0.16[0.07-0.22]g/m。近岸站点的水生昆虫密度从 4[1.33-15.33]增加到 56[22.00-86.67]n/m。软甲纲密度从 34.67[11.67-95.33]增加到 110[53.33-223.33]n/m，生物量从 0.43[0.11-1.00]增加到 1.48[0.50-2.00]g/m。与禁渔前相比，在多个站点重新发现了两种濒危的Margarya 物种。整个湖泊的大型无脊椎动物群落结构发生了显著变化，这主要归因于禁渔。大多数大型无脊椎动物物种的物种丰富度、密度和生物量的立即增加表明，这是减少捕捞压力和减轻湖泊栖息地干扰的综合影响。研究结果表明，禁渔有利于大多数淡水湖泊大型无脊椎动物的恢复。
