Sibaja-Cordero Jeffrey A, Cortés Jorge
Centro de Investigación en Ciencias del Mar y Limnología (CIMAR), Universidad de Costa Rica, San Pedro, 11501-2060 San José, Costa Rica.
Rev Biol Trop. 2010 Dec;58(4):1387-403.
Several biological and physical factors change the rocky shore communities. The desiccation time and the tolerance of the intertidal species produce the vertical zonation. In many studies around the world, a temporal change in this zonation is presented.In Costa Rica, only studies that include temporal trends were carried out in Punta Mala and Montezuma, Pacific coast in 80's. The rocky intertidal of the Cocos Island National Park, Costa Rica were surveyed photographically. The Chatham bay was sampled in three expeditions (January 2007, October 2007 and April 2008). Photos corresponding to 25x25cm quadrats were taken with the goal to determine diversity and composition differences in rocky shore organisms between sampling dates. The Wafer bay was sampled in January and October 2007. The intertidal of Chatham consists of basaltic rock, while Wafer has basaltic and ignimbrite boulders. The main difference between sites were the higher algae cover (erect-frondose forms) and number of organism bands at Chatham bay. Temporal change was not found in the total cover of sessile fauna and autotrophs. The barnacle Tetraclita stalactifera, that occurs above the algal fringe (lower intertidal), was the invertebrate with the highest coverage. The mobile fauna biodiversity presented no significant trend between sampled months. However, the identity of species, their cover and their abundance showed a moderate temporal change. In October 2007, when the sea surface temperature was 23 degrees C the infralittoral zone had an increase in green algae cover. The red algae (crust and erect-frondose forms) were dominant in January and April. The pulmonate limpet, Siphonaria gigas and a bacterial biofilm at mid littoral showed a negative association. The snails of the high littoral and the supralittoral zone showed a temporal change in their abundance, but with contrasting patterns between sites. The temporal variation in the assemblages increased from the supralittoral to the infralittoral possibly due to changes in the water temperature and climatic conditions, that could influence the intertidal zone during the high and low tide, respectively.
多种生物和物理因素改变着岩质海岸群落。干燥时间和潮间带物种的耐受性导致了垂直分带现象。在世界各地的许多研究中，都呈现出这种分带的时间变化。在哥斯达黎加，20世纪80年代仅在太平洋海岸的蓬塔马拉和蒙特苏马开展了包含时间趋势的研究。对哥斯达黎加科科斯岛国家公园的岩质潮间带进行了摄影调查。在三次考察（2007年1月、2007年10月和2008年4月）中对查塔姆湾进行了采样。拍摄了对应25×25厘米样方的照片，目的是确定不同采样日期之间岩质海岸生物的多样性和组成差异。在2007年1月和10月对韦弗湾进行了采样。查塔姆湾的潮间带由玄武岩构成，而韦弗湾有玄武岩和熔结凝灰岩巨石。各地点之间的主要差异在于查塔姆湾藻类覆盖度更高（直立叶状形态）以及生物带数量更多。在固着动物和自养生物的总覆盖度方面未发现时间变化。藤壶Tetraclita stalactifera出现在藻类边缘上方（低潮间带），是覆盖度最高的无脊椎动物。活动动物的生物多样性在采样月份之间未呈现显著趋势。然而，物种的身份、它们的覆盖度和丰度显示出适度的时间变化。2007年10月，当海面温度为23摄氏度时，亚潮带绿藻覆盖度增加。红藻（壳状和直立叶状形态）在1月和4月占主导。中潮带的肺螺帽贝、Siphonaria gigas和细菌生物膜呈现负相关。高潮带和潮上带的蜗牛在丰度上表现出时间变化，但不同地点的模式相反。群落的时间变化从潮上带向亚潮带增加，这可能是由于水温和气侯条件的变化，分别在涨潮和落潮期间影响潮间带。
