[Secondary productivity of macrobenthos in rocky intertidal zone of Yushan Islands, Zhejiang Province].

In order to understand the current status of macrobenthos in intertidal zone of Yushan Islands, macrobenthos samples were collected from 5 sections in the intertidal zone in four seasons from March 2009 to January 2010, with the density, biomass, secondary productivity, and P/B value of the macrobenthos investigated by using Brey's empirical formula. The mean density of the marobenthos was 1419.5 ind x m(-2), mean biomass in ash free dry mass (AFDM) was 565.53 g x m(-2), mean annual secondary productivity was 285.58 g x m(-2) x a(-1) (AFDM), and mean annual P/B value was 0.51. The secondary productivity was mainly affected by mollusca and gastropda, with five critical species Septifer virgatus, Modiolus modiolus, Serpulorbis imbricata, Tetraclita japonica, and T. squamosa contributed 84.0% of the total. The P/B value in the study area was lower than that in other sea areas, showing that the generation turnover rate of the macrobenthos in the intertidal zone of Yushan Islands was slower, and the community structure was more stable.

[Macrobenthic faunal diversity in Xiangshan Bay].

In order to understand the community pattern and biodiversity of macrobenthic fauna in Xiangshan Bay, an eight cruises survey was made at thirteen stations of the Bay from July 2006 to August 2007, with the dominant species composition, richness, biomass, secondary productivity, and P/B value of macrobenthic fauna investigated, and the species diversity of the macrobenthic fauna analyzed. A total of 123 macrobenthos species were recorded, including 48 species Mollusc, 33 species Crustacea, 12 species fish, 12 species annelid polychaete, 8 species echinoderms, and some coelenterates and nematodes. The dominant species were more concentrated, and the dominance index was higher. The average secondary productivity of the macrobenthic fauna was 16.70 g x m(-2) x a(-1), and the average P/B value was 0.60. There existed distinct variations (P < 0.01) in the species richness index (d), evenness index (J), Simpson's diversity index (D), and Shannon diversity index (H) among different survey stations, and distinct variations (P < 0.01) in the indices except evenness index (J) between years.