南极普里兹湾临近海域夏季纽鳃樽对浮游植物的摄食研究

GRAZING OF SALPA THOMPSONI ON PHYTOPLANKTON IN SUMMER IN THE PRYDZ BAY,ANTARCTICA

于 1 998年 1 2月至 1 999年 1月南极夏季 ,对南大洋普里兹湾临近海域主要被囊类纽鳃樽的数量密度分布进行了现场调查 ,同时于 - 3站对纽鳃樽对浮游植物的摄食率利用肠道色索法和颗粒递减法进行了现场研究。调查结果表明 ,纽鳃樽主要分布于调查海区的浮冰区北部边缘及其以北的开阔水域。在密集区其数量密度高达 2 795ind..1 0 0 0 m- 3,浮冰区几乎没有发现。 - 3站现场摄食实验结果显示 ,纽鳃樽个体肠道色素含量变化范围为 0 .1 4～ 1 .2 7μg.ind.- 1,平均为0 .98μg.ind.- 1。肠道色素法测得的纽鳃樽对浮游植物的摄食率为 7.9μg.ind.- 1d- 1,滤水率为2 81 ind.- 1d- 1。颗粒递减法测得纽鳃樽滤水率为 1 5.3± 4.61 ind.- 1d- 1,比肠道色素法所得结果偏低。虽然由此推算纽鳃樽群体的日摄食量只占浮游植物现存量的 0 .8% ,但是对于初级生产力却有一定的摄食压力 ( 72 .2 % )。

Abstract During the CHINARE XV cruise in austral summer of 1998/1999, the abundance and feeding activity of salpa thompsoni were estimated in the Prydz Bay region. Salps samples were collected by vertical tows from 200m to the surface with a conical net of 330μm mesh size. At Ⅳ 3 station, the grazing rates were estimated by the gut fluorescence method and culture experiments. S.Thompsoni mainly distributed in the northern part of the survey area, and its maximum densities was reached to 2795ind. 1000m -3 . A dramatic decrease in salp stock was observed at the marginal ICE Zone. The results of the feeding experiments at the Ⅳ 3 showed: The gut pigments levels of S. Thompsoni was 0.14-1.27μg·ind. -1 (average 0.98μg·ind. -1 ). The individual ingestion rate was 7.9μg(chla)ind. -1 d -1 , and the filtration rate was 28 l·ind. -1 ·d -1 . Through the daily grazing rate of S. Thompsoni was less than 1% of the phytoplankton standing stock, it showed a grazing impress on the primary production (72.2%). [WT5HZ]