过度捕捞对沅江怀化段鱼类资源的影响与对策

Influence and Countermeasures of Overfishing on Fish Resources in Huaihua Section of Yuanjiang River

本调查研究于2017年6月至2019年12月进行。调查研究发现,在近三十多年时间里,沅江怀化段天然捕捞产量出现了一个“小山顶”形态,而捕捞产量的增长与下降都与捕捞努力量的增加直接相关。在1984~2008年的24年是“爬坡阶段”,由最低年份1984年1067 t上升到最高年份2008年6288 t,上升幅度高达4.89倍;2008~2019年的11年是“下坡阶段”,从最高年份2008年6288 t下降到2019年2767 t,下降幅度为56.00%。2018年与1984年相比,天然捕捞产量在水产品总产量中的比重下降了71.37%。2019年捕捞单产为40.7 kg/hm2,比1984年增加23.0 kg/hm2,但折合每年只增加0.66 kg/hm2。2018年天然捕捞年单船产量为0.8682 t,比1984年增加了0.5784 t,增加幅度近2倍,靠的是捕捞工具升级,捕捞努力量显著增加。主要是机动渔船数量的大幅增加和渔具渔法的不断改进。其中,捕捞渔民人口增加3.25倍,机动渔船增加1.87倍,捕捞渔具增加2.21倍。同时,沿江两岸非法捕捞、竭泽而渔和酷渔滥捕的现象很常见,对鱼类资源的破坏和危害十分严重。在鱼类资源出现持续衰退的情况下,继续开展高强度和大规模的捕捞生产,付出很多,得到减少,致使很多渔民不得不弃渔上岸,背井离乡谋生计,同时对鱼类资源的危害也犹如“雪上加霜”。原有的捕捞“渔汛”已经不明显,或者基本消失了,以至于越捕越少,越捕越小,渔民越捕越穷,资源越捕越衰。采取措施控制捕捞强度,防止鱼类资源加速衰退,实现渔业可持续发展,显得十分迫切和重要。

This survey study was conducted from June 2017 to December 2019. The investigation and research found that in the past 30 years, the natural fishing output of the Huaihua section of the Yuanjiang River has appeared a “hill top” shape. Both increases and decreases in fishing yields are directly related to increases in fishing effort. The 24 years from 1984 to 2008 was the “climbing stage”. From 1067 t in the lowest year in 1984 to 6288 t in the highest year in 2008, the increase rate is as high as 4.89 times. The 11 years from 2008 to 2019 were the “downhill stage”, which dropped from 6288 t in 2008 to 2767 t in 2019, a decline of 56.00%. The fishing yield in 2019 was 40.7 kg/hm2, an increase of 23.0 kg/hm2 compared with 1984, but only increased by 0.66 kg/hm2 every year. In 2018, the annual single-vessel output of natural fishing was 0.8682 t, an increase of 0.5784 t compared with 1984, an increase of nearly 2 times. It was due to the upgrading of fishing tools and a significant increase in fishing effort mainly due to the substantial increase in the number of motorized fishing boats and the continuous improvement of fishing methods. Among them, the population of fishing fishermen increased by 3.25 times, motorized fishing boats increased by 1.87 times, and fishing gear increased by 2.21 times. At the same time, illegal fishing, depleted fishing and excessive fishing are common on both sides of the river, causing serious damage and harm to fish resources. In the case of the continuous decline of fish resources, high-intensity and large-scale fishing production continued to be carried out, and the cost was greatly reduced. As a result, many fishermen had to abandon fishing and go ashore, leaving their hometowns to make a living. At the same time, the harm to fish resources is also similar to “To make matters worse.” The original fishing “fishing season” is no longer obvious, or has basically disappeared, so that the more and less the catch is, the smaller the catch is, the fishermen are getting poorer and poorer, and the resources are getting worse and worse. It is very urgent and important to take measures to control the fishing intensity, prevent the accelerated decline of fish resources, and realize the sustainable development of fishery.