Aouth American intertidal systems and El Nino

1999年至2001年对秘鲁中部沿海生态系统进行了一项研究。该研究包括对安孔和帕拉卡斯两个主要地区的定期调查，以及在安孔南部夏季进行的一系列密集观察和抽样。以往研究的数据也被纳入本研究。厄尔尼诺现象引起的海洋异常被认为会影响对该地区渔业至关重要的沿海鱼类物种（如凤尾鱼）的动态，但它们对南美洲低至中纬度地区海岸生态系统的影响却知之甚少。收集并分析了秘鲁岩石海岸主要生物的长期动态数据，特别是两种海星，Heliaster helianthus和Stichaster striatus，与厄尔尼诺事件的发生有关。两种在年和季节尺度上均表现出不同的种群消长模式。在包括厄尔尼诺年在内的10 a时间内，太阳花的种群数量呈下降趋势，而条纹花的种群数量呈上升趋势，并在南方秋冬季达到年（季）高峰。另一方面，海星的主要猎物，贻贝，似乎表现出一种不同于捕食者的波动模式，但与厄尔尼诺事件的发生有一定的关系。继续进行这项研究，包括进一步分析现有数据，将是富有成果和值得的。

A study on the coastal ecosystems of central Peru was undertaken from 1999 to 2001. The study consisted of regular surveys of two main areas, Ancon and Paracas, and a series of intensive observations and sampling in austral summer in Ancon. Data from previous studies were also incororated in the present study. Oceanographic anomalies caused by El Nino phenomenan are considered to affect the dynamics of coastal fish species which are important for fisheries in this region (e.g.anchovy Engraulis ringens), but their influences on the shore ecosystems of low- to mid- latitude zones of South America are poorly known. Data on the long-term dynamics of major organisms on Peruvian rocky shores, in particular two species of starfish, Heliaster helianthus and Stichaster striatus, were gathered and analysed in relation to the occurrence of El Nino events. The two species demonstrated contrasting patterns of population fluctuation on both yearly and seasonal scales. Over a 10-ear period including El Nino years H.helianthus showed a declining population trend, while S.striatus showed an increasing trend with annual (seasonal) peaks in austral autumn/winter. On the other hand, starfishes' main prey, mussels, appeared to demonstrate a pattern of fluctuation which is different from the predators' patterns ut somewhat related to the occurrence of El Nino events. Continuation of this research including further analyses of available data will be fruitful and worthwhile.