关键词: 生态土地分类, 生态单位, 生态分类系统, 景观

Abstract: In order to fully understand the efficiency of multi-mesh gillnets (MGN) and multi-mesh trammel nets (MTN) in collecting fish from soft bottom and hard bottom habitats, a 5day trial in the sandy beach (SB) and rocky reef (RR) habitats around Gouqi Island of East China was conducted in October 2011. The fish collection efficiency of MGN and MTN in SB and RR was compared from the viewpoints of fish composition, fish collection way, dominant fish composition and their relative abundance, and fish diversity indices and community patterns. The fish species collected by MTN were five more in SB and eight more in RR, as compared with those collected by MGN. In SB, the dominant fish species collected by MGN were Sardinella zunasi and Larimichthys polyactis, while those collected by MTN were S. zunasi, L. polyactis, and Paraplagusia japonica; in RR, only Sebastiscus marmoratus and Hexagrammos agrammus were the dominant fish species collected by MTN, while two more dominant fish species, i.e., Sardinella zunasi and L. polyactis, were collected by MGN. The fish collection ways of MTN and MGN differed. Most of the individuals collected by MGN both in SB and in RR were wedged, and only a small part of the individuals were gilled and entangled, whereas the percentages of gilled, entangled, and some other combined ways collected by MTN in the two habitats were increased significantly. In SB, the catch rates of S. zunasi and L. polyactis by MGN were significantly higher than those by MTN, while that of P. japonica was in contrary; in RR, MTN had higher catch rates of S. marmoratus and H. agrammus, while MGN indicated significantly higher catch rates than MTN. There were significant differences in the species diversity indices between the samples collected by MGN and MTN in SB, but no significant differences in RR. The cluster and ordination based on the abundance data indicated the significant differences in the fish community structure between MGN and MTN both in SB and in RR. It was suggested that when collecting fish with gillnets, it needed to design suitable nets and methods to get comprehensive information on the real fish assemblages.