Dinoflagellate cyst records in recent sediments from Daya Bay, South China Sea
Dinoflagellate cyst records in recent sediments from Daya Bay, South China Sea
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DOI：
10.1111/j.1440-183.2004.00357.x
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发表时间：
2004-12
影响因子：
1.5
通讯作者：
Zhaohui Wang;K. Matsuoka;Yu-zao Qi;Jufang Chen;Songhui Lu
中科院分区：
文献类型：
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作者：
Zhaohui Wang;K. Matsuoka;Yu-zao Qi;Jufang Chen;Songhui Lu
2001年8月，东京大学渔业海洋实验室取样器在南海大亚湾两个海盆采集了9个长8 ~ 26 cm的沉积物岩心，研究了鞭毛藻休止囊的分布。在本研究中，从65份沉积物样本中鉴定出51种不同的囊肿形态，代表22属。其中自养种21种，异养种30种。每个样本的囊孢物种丰富度在12 ~ 29之间，Shannon - Weaver多样性指数（H’）在0.15 ~ 4.13之间。2 ~ 6 cm沉积物的物种丰富度和价值均有明显增加。每克干重沉积物的囊肿浓度从154到113 483个不等，在上层沉积物中要高得多。恙螨杆菌是最主要的囊型，占上部沉积物囊组合的90%以上。2000年大亚湾表层沉积物中棘球藻囊的急剧增加反映了该物种的大量繁殖。囊状组合结果显示了该区水质的变化趋势，属于典型的人工富营养化污染类型，从20世纪80年代开始，到90年代中期急剧加速。该地区Alexandrium的囊肿以catenella Alexandrium和tamarense Alexandrium complex的囊肿为主，出现频率和浓度最高，分别为503个/ g干重沉积物和22.3%。大量的亚历山大菌囊为亚历山大菌的繁殖提供了丰富的“种子床”，也是麻痹性贝类中毒毒素的重要来源，特别是在冬季。
Nine sediment cores of 8–26 cm in length were collected from two basins of Daya Bay, the South China Sea, by Tokyo University Fisheries Oceanography Laboratory core sampler in August 2001 to investigate the distribution of dinoflagellate resting cysts. In the present study, 51 different cyst morphotypes representing 22 genera were identified from 65 sediment samples. Among them, there were 21 autotrophic species and 30 heterotrophic ones. Cyst species richness in each sample varied from 12 to 29, while the values of Shannon‐Weaver diversity index (H′) were between 0.15 and 4.13. There were an obvious increase in both species richness and values of H′in 2–6 cm sediments. Cyst concentrations varied from 154 to 113 483 cysts per gram dry weight sediment, and were much higher in upper sediments. Scrippsiella trochoidea was the most dominant cyst type, which took up over 90% of cyst assemblages in the upper sediments. The abrupt increase of S. trochoidea cysts in the surface sediments reflected the bloom of this species in Daya Bay in 2000. The results from cyst assemblages showed some trend of changes in water quality in this area, and indicated a typical type of pollution caused by cultural eutrophication, which started in the 1980s and greatly accelerated in the middle of 1990s. Cysts of Alexandrium, mainly those of Alexandrium catenella and Alexandrium tamarense complex, occurred frequently and abundantly in this area, with the highest concentration and relative frequency of 503 cysts per gram dry weight sediment and 22.3%, respectively. The high abundance of Alexandrium cysts provided rich ‘seed bed’ for Alexandrium blooms and was also an important source of paralytic shellfish poisoning toxins, especially in winter.