A grid of 22 stations,giving a broad geographic coverage of the Bohai Sea and the Bohai Strait was selected.Undisturbed sediments were collected from sampling stations during cruises in June 1997,in September/October 1998 and again in April/May 1999.Based on the results of Juario (1975),the average biornass,0.404 g/(m²·a) of meiofauna (including nematode,harpacticoida,bivalve larvae,polycheata and kinorhyncha) in the Bohai Sea is given and accounts for 4.5 percent of the macrofauna in the Bohai Sea.The horizontal distribution of the biomass of meiofauna showed that it was higher at the stations of middle east part of the Bohai Sea and the strait in 1998 and 1999 cruises and it decreased at the stations near to the strait mouth and increased at Station B1 in 1999 cruise.The annual average production in the Bohai Sea is 3.636 g/m² calculated in term of the formula P=9B.Compared with the biomass of other sea areas in the world,the biomass of the Bohai Sea is similar but slightly lower.The individual average dry weight of nematodes given by different authors is analyzed.

Abundance and biomass of heterotrophic microbes were investigated using epifluorescense microscopy in August 2004 along a transect in the Kongsfjorden, a glacial fjord in the high arctic, located in the north-western part of Svalbard. A bacterial abundance was low at outer fjord stations (on average 2.29×10⁸ ind./dm³) and was higher at inner fjord stations (on average 3.52×10⁸ ind./dm³).The biomass of bacteria ranged from 3.69 to 8.01 mg/m³.The abundance of bacteria was low at the surface of water(0 m), whereas the higher abundances often occurred at depths of 30~50 m. The abundance of heterotrophic flagellates varied from 2.785 to 8.891×10⁴ ind./dm³.The assemblage was numerically dominated by less than 5 μm heterotrophic flagellates (78.67%~94.80%).The biomass of heterotrophic flagellates varied from 0.37 to 2.30 mg/m³.The mean biomass distribution for all stations was 4.91% for less than 5 μm heterotrophic flagellates, 86.74% for 6~20 μm flagellates and 8.35% for greater than 20 μm sized flagellates.The lowbiomass of heterotrophic flagellates often occurred at the surface of water (0 m),while the maximum value of biomass occurred at different depths.The biomass of total heterotrophic microbial community ranged from 4.20 to 10.03 mg/m³.The mean biomass distribution for all stations was 82.58% for bacteria, 15.77% for flagellates and 1.66% for ciliates.

On the basis of the materials collected from six cruises during 1986-1990 in the Kuroshio and its adjacent waters of the East China Sea,the spatial and temporal changes of zooplankton biomass and the relation to certain environmental factors are analysed in this paper.The results indicated that the biomass peaked in autumn,followed by spring and summer and was the lowest in winter.Its horizontal distribution pattern was higher in the continental shelf area than in the Kuroshio area and in the north than in the south of the surveyed area.The higher biomass regions usually occurred in the fronts between different currents and water masses and in the upwelling region of the Kuroshio subsurface water,and were mainly composed of warm-water eurytopic species and tropic oceanic eurytopic species.The relationship between the vertical distribution of zooplankton biomass(Z_w)and water depth(D) might be expressed by the formual LnZ_w=a+bXD.The biomass was observed higher in the upper 100 m.The positive correlation between the biomass of bait-animal and the abundance of larval and juvenile fishes was significant.In addition,the higher biomass region in the northern study area (in the vicinity of 29°N,126°E) overlapped the fishing ground of mackerel and scads in the middle East China Sea.

The biomass, species composition and diversity of benthic diatom assemblages in mud-flat soils in Kandelia candel (L.) Druce communities with and without vegetation were studied seasonally at the Houyu Bay in Fuding City, Fujian Province, China. A total of 103taxa were identified (including varieties). Eighty-four taxa were found in the mud-flat with vegetation and 74 taxa in the mud-fiat without vegetation, while the biomass was large in January and April and decreased from July to October. The most abundant species in the mud-flat with vegetation are Nitzschia cocconeiformis, Gyrosigma scalproides and N. Fasciculata, compared with G. Scalproides and N.obtusa var. Scalpelliformis in the mud-flat without vegetation. High H' values at 2 sites during all seasons suggest that diatom assemblages in the sediments of the Houyu Bay represent an original environment. Multi-dimensional scaling of diatom assemblages from mud-flats with and without vegetation shows that a slight seasonal change and only a single association occur in the angroves.

Fish biomass is a critical component of fishery stock assessment and management and it is often estimated from ocean primary production (OPP). However, the relationship between the biomass of a fish stock and OPP is always complicated due to a variety of trophic controls in the ecosystem. In this paper, we examine the quantitative relationship between the biomass of chub mackerel (Scomber japonicus) and net primary production (NPP) in the southern East China Sea (SECS), using catch and effort data from the Chinese mainland large light-purse seine fishery logbook and NPP derived from remote sensing. We further discuss the mechanisms of trophic control in regulating this relationship. The results show a significant non-linear relationship exists between standardized CPUE (Catch-Per-Unit-Effort) and NPP (P<0.05). This relationship can be described by a convex parabolic curve, where the biomass of chub mackerel increases with NPP to a maximum and then decreases when the NPP exceeds this point. The results imply that the ecosystem in the SECS is subject to complex trophic controls. We speculate that the change in abundance of key species at intermediate trophic levels and/or interspecific competition might contribute to this complex relationship.

Seasonal variations of phytoplankton/chlorophyll-a (Chl-a) distribution, sea surface wind, sea height anomaly, sea surface temperature and other oceanic environments for long periods are analyzed in the South China Sea (SCS), especially in the two typical regions off the east coast of Vietnam and off the northwest coast of Luzon, using remote sensing data and other oceanographic data. The results show that seasonal and spatial distributions of phytoplankton biomass in the SCS are primarily influenced by the monsoon winds and oceanic environments. Off the east coast of Vietnam, Chl-a concentration is a peak in August, a jet shape extending into the interior SCS, which is associated with strong southwesterly monsoon winds, the coastal upwelling induced by offshore Ekman transport and the strong offshore current in the western SCS. In December, high Chl-a concentration appears in the upwelling region off the northwest coast of Luzon and spreads southwestward. Strong mixing by the strong northeasterly monsoon winds, the cyclonic circulation, southwestward coastal currents and river discharge have impacts on distribution of phytoplankton, so that the high phytoplankton biomass extends from the coastal areas over the northern SCS to the entire SCS in winter. These research activities could be important for revealing spatial and temporal patterns of phytoplankton and their interactions with physical environments in the SCS.

Being a primary producer, Microphytobenthos (MPB) play an important role in the benthic ecosystem of mangrove swamps. The temporal and vertical distribution of MPB biomass, expressed as chlorophyll a (Chl a), was investigated in mangrove swamps on the Qi'ao island and the Futian Mangrove Nature Reserve, Guangdong Province, South China. Both locations are situated in the Zhujiang (Pearl River) Estuary. For each location, bi-monthly sampling was carried out at four sites during low tide period. Except one site on the Qi'ao Island, which was in Phragmites australis marsh, all sites were in mangrove swamps. The Chl a concentration in surface (0-1 cm) sediment ranged from 0.2 μg/cm³ to 8.3 μg/cm³ in the Qi'ao Island and from 2.1 μg/cm³ to 15.6 μg/cm³ in the Futian Mangrove Reserve. The peak Chl a concentration occurred in winter or early spring, while the lowest Chl a concentration, with a value of about one quarter of the peak, was observed in summer or early autumn. The vertical distribution of Chl a concentration exhibited an exponential decline with depth, which indicated a muddy sediment with high organic matter, and the slope of the curve was positively related to Chl a concentration in the surface sediment. The MPB biomass of the Qi'ao Island was significantly lower than that of the Futian Mangrove Reserve. Our results suggest that the overlaying water quality might influence the MPB biomass in surface sediments.

This paper makes an analysis and study of the plankton samples collected from the Kuroshio and its adjacent area in the north of the East China Sea during the seven successive years(from 1986 to 1992) in the implementation of the programme "China-Japan Joint Research on the Kuroshio" as well as a brief summary of the distribution of the biotnass of food zooplankton and its relation to the oceanic environment.The results indicate that the biomass of zooplankton in the study area is relatively low,with en annual mean of 71.22 mg/m³ only.The seasonal variation of biomass is not obvious and salinity is an important factor influencing seasonal and annual variations of zooplankton biomass in the study area.The Kuroshio front in the East China Sea and the Tsushima Warm Current front divide the study area into two parts from north to south in the vicinity of the 200 m isobath:the biotrtass in the western part was greater than 50 mg/m³,whereas was less than 50 mg/m³ in the eastern part.The spetiotemporal distributions of different ecological groups of zooplankton and their biotrutss basically reflect the basic features of the hydrological conditions in each season in the study area.

Sea was selected. Undisturbed sediments were taken from sampling stations during the cruise in June 2003. The average abundance of meiofauna is (1 584±686) ind./10cm², with corresponding biomass (dwt) of(1 086±425) μg/10cm². The pattem of abundance of meiofauna is similar to the pattern ofbiomass. There are 65.88% meiofauna in 0~2 cm sediments, 27.66% in 2~5 cm sediments and 6.47% in 5~8 cm sediments.The Spearman correlation analysis between meiofauna and environmental factors shows that abundance of meiofauna, free living marine nematodes, benthic copepods has significant positive correlations with Chl-a. And the abundance of copepods has significant positive correlations with several factors such as Chl-a, Pha-a, Chl-a plus Pha-a and organic matter. A total of 18 meiofauna groups are identified. Nematode is the most dominant group, average abundance (1 404±670) ind/10cm², accounting for 88.65%, and the following groups are also important:benthic copepods (5.48%), kinorhyncha (1.26%), polychaeta (1.07%). By biomass, dominant groups are nematodes (51.72%), polychaeta (21.84%), copepods (14.87%), ostracoda (4.92%), kinorhyncha (3.67%). A total of 90 species of nematodes are identified. The species composition of nematodes is listed based on selected two stations 7794 (coastal area) and 10694(cold water mass in deep waters).

The temporal variations of mesozooplankton abundance and biomass (1-Volumetric method by settling volume and displacement volume and 2- Gravimetric method through wet weight, dry weight and ash-free dry weight) with relation to environmental parameters were studied in the mangrove creek area of Karachi coast, Pakistan. The data of mesozooplankton samples along with environmental parameters (temperature, salinity, pH, etc.) were collected during January 1998 to December 1998 from two creek stations. The abundance of mesozooplankton also exhibited seasonal trends at both stations. At Sta. S2, the highest and lowest abundance values were observed during post-monsoon and southwest monsoon respectively whereas, at Sta. S1, a clear trend of high abundance in pre-monsoon to low abundance in southwest monsoon was observed. Mesozooplankton abundance was also positively correlated with settling volume, displacement volume, wet weight and dry weight. The highest biomass value was observed in the northeast monsoon and pre-monsoon periods. The results of the canonical analysis of the output from the discriminate function was tested. Out of fifteen variables, only one was significantly different in single character ratios dry weight/ash free-dry weight (F_3,23=4.78, P<0.005). The mesozooplankton community was collectively composed of 28 taxa. Among these groups, copepoda (66.3%), gastropod larvae (9.94%), evadne (4.60%), zoea (3.60%), cypris nauplii (2.56%), lemellibranch larvae (1.87%), chaetognaths (1.81%), ostracods (1.73%), lucifer (1.15%) and barnacles nauplii (1.35%) contributed the most to the similarities within Sta. S1, while copepoda (74.68%), cypris nauplii (5.29%), gastropods (4.87%), barnacles nauplii (4.81%), evadne (1.72%), zoea (1.53%) and caridean larvae (1.18%) at Sta. S2. The remaining mesozooplanktonic group were accounted for less than 5% and 6% at Sta. S1 and Sta. S2 respectively, of the total organisms. Similarity percentage (SIMPER) analysis revealed that copepoda, gastropod larvae and cyprus nauplii contributed most of the similarities within Sta. S2 along Sta. S1.