Aouth American intertidal systems and El Nino

1999年至2001年进行了一项关于秘鲁中部沿海生态系统的研究。这项研究包括对安康和帕拉卡斯两个主要地区的定期调查，以及安康南半球夏季的一系列密集观测和采样。来自先前研究的数据也在本研究中得到了关联。厄尔尼诺现象引起的海洋异常被认为影响对该区域渔业很重要的沿海鱼类物种的动态，但其对南美洲中低纬度地区海岸生态系统的影响知之甚少。收集了关于秘鲁岩石海岸主要生物长期动态的数据，特别是两种海星--向日葵和条斑海星，并分析了它们与厄尔尼诺事件发生的关系。这两个物种在年度和季节尺度上表现出截然不同的种群波动模式。在包括厄尔尼诺现象的10年间，向日葵种群数量呈下降趋势，而条纹藻种群数量呈上升趋势，其年(季节)高峰出现在南半球的秋冬季。另一方面，海星的主要猎物贻贝似乎表现出一种与捕食者不同的波动模式，但与厄尔尼诺事件的发生有一定的联系。继续这项研究，包括对现有数据的进一步分析，将是富有成果和有价值的。

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.