摘要
根据 1 998年 9月和 1 999年 4月两次调查研究表明 :1 998年秋季 ,调查区 (37°N～ 41°N,1 1 7.5°E～1 2 2 .5°E)表层叶绿素 a浓度介于 0 .0 4 6～ 5.885 mg/ m3,平均为 1 .892 mg/ m3;1 999年春季介于 0 .1 70～8.0 92 mg/ m3,平均为 1 .62 1 mg/ m3。叶绿素 a的平面分布与历史资料相近月份的分布趋势基本一致 ,调查区南部是整个调查海区的高值区 ,而西部及渤海海峡在不同时期出现过高值 ,中央海区叶绿素 a的浓度都比较低。叶绿素 a浓度剖面分布在春季是从调查区西部、渤海中部到渤海海峡依次增高 ,而秋季刚好相反 ;从调查区南部、渤海中部到北部的变化趋势在春季和秋季都是依次降低的。在连续站进行的现场测量碳同化数介于 0 .2 63～ 4.649mg C/ (mg Chla· h)之间 ,平均值为 1 .91 6 mg C/ (mg Chla· h)。 1 998年秋季 ,调查区水柱初级生产力介于 1 0 .1～ 458.3 mg C/ (m2· d) ,平均为 1 63.6 mg C/ (m2· d) ,初级生产力的高值区位于海峡口附近。1 999年春季 ,介于 64.9～ 740 .6mg C/ (m2· d) ,平均为 32 3.7mg C/ (m2· d) ,初级生产力的高值区位于海峡口附近和黄河口附近。同历史资料相比 ,初级生产力有所下降。观测和模型的结果表明 ,渤海浮游植物生物量的分布与水文条件密切相关 ,而初?
Based on the two cruises of ecosystem co mprehensive surveys carried out in the Bohai Sea (37°N～41°N, 117.5°E～122.5°E) in Se ptember 1998 and April 1999, the distribution of phytoplankton biomass, primary productivity and its relationship with environmental factors were studied. In every cruise, there were twice station grid surveys. Between these two stat ion grid surveys, five anchor stations and a 3 days drift experiment was carried out. Water samples were taken from 0m, 5m, 10m, 20, 30m, 40m, and bottom accord ing to the water depth. Chlorophyll samples were filtered on board onto Wateman GF/F filter immediately with carefully shaking before filtering. Chlorophyll a w as extracted and measured according to procedures of UNESCO's spectrometer metho ds under 750nm, 630nm, 647nm and 664nm wavelength. The relative photosynthesis r ate and assimilation number was measured at anchor stations by determination the dissolve oxygen changes in black and white incubation bottles, which were place d under water on in situ conditions. Dissolved oxygen was determined by Winkler method. Primary productivity was estimated according to Cadée method. Nutrient, hydrological data and meteorological data were supplied by the workgroups in th e campaign. In autumn 1998, the chlorophyll a concentration of surface layer was between 0 .046～5.885 mg/m3, the mean value was 1.892 mg/m3. The horizontal distri bution pattern of surface chlorophyll a concentration shown that, the chlorophyl l a concentration was high in the Laizhou Bay, low in the Central Bohai Sea, and at middle level in the Bohai Bay or Bohai Strait. In spring 1999, the chlorophy ll a concentration of surface layer was between 0.170～8.092 mg/m3, the mean value was 1.621 mg/m3. The concentration of surface chlorophyll a concentrat ion was high in the Laizhou Bay and the Liaodong Bay, low in the Bohai Strait. T he horizontal distribution pattern of chlorophyll a was similar to the history d ata. The subsurface chlorophyll a maximum (SCM) appeared around the Bohai Strait in the spring cruise, it is correlate to the stability of water mass, this phen omena approved by vertical profiles of stratification cause by temperature accum ulation. The vertical profiles of chlorophyll a concentration shown a featured p attern in autumn and spring cruises. The concentration of chlorophyll a became g radually higher across the section of the Bohai Bay, the Central Bohai Sea and t he Bohai Strait in spring, and it was in reverse in autumn cruise. It became gra dually lower across the section of the Laizhou Bay, the Central Bohai Sea and th e Bohai Strait in spring and autumn cruises. The assimilation numbers, that were measured in field in anchor stations, were between 0.263～4.649 mgC·mgChla -1·hour -1, and mean value was 1.916 mgC·mgChla -1·hour -1 . In autumn 1998, the primary productivity in water column was between 10.1～ 458.3 mgC·m -2·day -1, the mean value is 163.6 mgC·m -2·day -1; In spring 1999, the primary productivity in water column was between 6 4.9～740.6 mgC·m -2·day -1, the mean value was 323.7 mgC·m -2 ·day -1. The high value of primary productivity lay nearby the Bohai St rait and estuary of the Huanghe River, it is because the nutrient supplement fro m rive and sediment were plenteous near the Huanghe River estuary, and the eupho tic zone was deep around the Bohai Strait. Comparison with seasonal history data , the primary productivity in the Bohai Sea was decreasing. The correlation analysis between chlorophyll a concentration and the other env ironmental factors in autumn cruise in 1998 shown that, silicate and phosphate c oncentration had a closed related with chlorophyll a concentration. These indica ted the nutrient limitation of phytoplankton growth of these two nutrients in th e Bohai Sea during the investigation period. The horizontal distribution of thes e two nutrient concentrations and N/P ratio (Nitrogen and Phosphate ratio) also support this opinion. The particular or dissolved organic carbon and nitrogen we
出处
《生态学报》
CAS
CSCD
北大核心
2003年第3期517-526,共10页
Acta Ecologica Sinica
基金
国家自然科学基金资助项目 (4 0 2 0 60 2 0 )
国家基础研究与重点资助项目 (2 0 0 1CB4 0 970 2 )~~
关键词
叶绿素
浮游植物
初级生产力
渤海
phytoplankton
chlorophyll
primary productivity
the Bohai Sea
