ABSTRACT

The dynamics of fishery resources were analysed and compared before and after artificial reefs were deployed in the Dongshan Sea of Huizhou, Guangdong Province, China based on acoustic detection and trawl sampling methods. Species assessed by acoustic detection were mainly distributed in the middle water layers, and those collected by trawl sampling were mainly benthic organisms. Therefore, it was necessary to integrate the two methods aimed at organisms living in different water layers to improve the reliability of the assessment results. The comprehensive assessment results showed that the densities of fishery resources on artificial reefs and in the surrounding waters after the reefs were deployed were 58,302 inds/km² and 69658 inds/km², which were overall higher than that (60159 inds/km²) before artificial reef deployment. Some species, such as Parargyrops edita, usually hide inside the artificial reefs and cannot be detected or caught after the artificial reef deployment, which leads to a lower density being recorded than before artificial reef deployment. Furthermore, according to the results of single echo detection and nautical area backscattering coefficient analysis, the proportion of large- and medium-sized marine organisms increased after artificial reefs were deployed, and these organisms were mainly distributed in middle and deeper water layers. These observations indicated that the construction of artificial reefs could provide sufficient conditions for the growth of marine organisms and induce the large- and medium-sized individuals to deeper water layers.

摘要

根据声学检测和拖网采样方法，对在广东惠州东山海部署人工鱼礁前后的渔业资源动态进行了分析和比较。通过声学检测评估的物种主要分布在中间水层，而通过拖网采样收集的物种主要是底栖生物。因此，有必要将针对生活在不同水层中的生物的两种方法结合起来，以提高评估结果的可靠性。综合评估结果表明，部署珊瑚礁后，人工鱼礁和周围水域的渔业资源密度分别为58,302 inds / km ²和69658 inds / km ²，总体上高于人工礁部署前的水平（60159 inds / km ²）。一些种类，如Parargyrops edita，通常隐藏在人造礁石内部，并且在人造礁石部署之后无法被检测到或捕获，这导致记录的密度低于人造礁石部署之前的密度。此外，根据单回波探测和海域后向散射系数分析的结果，在部署人工鱼礁后，大中型海洋生物的比例增加，这些生物主要分布在中，深水层。这些观察结果表明，人工鱼礁的建设可以为海洋生物的生长提供充分的条件，并促使大中型个体进入更深的水层。