南极夏季南设得兰群岛周边海域浮游动物优势种群的分布、丰度及种群结构分析

根据2013/2014年夏季在南极南设得兰群岛周边海域使用北太平洋网采样品及同步环境调查资料,分析了南极大磷虾(Euphausia superba)、拟长臂樱磷虾(Thysanoessa macrura)、尖角似哲水蚤(Calanoides acutus)和近缘哲水蚤(Calanus propinquus)这四种优势浮游动物的丰度和分布特征。结果表明,南极大磷虾和拟长臂樱磷虾在南设得兰海域均有较为广泛的分布,其中南极大磷虾丰度较高,且它们的水平分布存在一定程度的空间分离。在研究海域东部的南奥克尼群岛(South Orkneys)邻近海域发现了大量的南极大磷虾原蚤状C期幼体,表明大磷虾曾于1月中上旬左右产卵繁殖。研究海域的东部南极大磷虾种群结构以幼体前期为主,而西部的种群结构则以幼体后期、未成体和成体为主。尖角似哲水蚤和近缘哲水蚤的空间分布也较为广泛,且两者分布基本一致。东部南奥克尼群岛临近海域的浮游植物浓度较低,这可能是大量南极大磷虾幼体和桡足类摄食活动的结果。

ABUNDANCE AND STRUCTURE OF DOMINANT ZOOPLANKTON SPECIES IN AUSTRAL SUMMER NEAR SOUTH SHETLAND ISLANDS, ANTARCTICA

Two krill species (Euphausia superba and Thysanoessa macrura) and two copepod species (Calanoides acutus and Calanus propinquus) were sampled with Norpac net near South Shetland Islands, Antarctica in austral summer of 2013/2014. The distribution, abundance, and population structure of the four species were studied with in-situ environmental parameters. The results show that the abundance of E. superba was higher than that of T. macrura; they distributed widely but in different areas. A large amount of the first calyptopis stage of E. superba was found around South Orkneys, indicating that E. superba reproduced in early January in 2014. The early stages of E. superba larvae dominated in the eastern part of the survey area, while the juveniles and adults dominated in the western part. The two copepods distributed widely in the southern ocean, and they occupied similar sea areas. The concentration of phytoplankton was low in around South Orkneys, which might be due to the grazing impact of the large amount of E. superba larvae and copepods.