Spatial and temporal variation in barnacle growth in a coastal upwelling system
Spatial and temporal variation in barnacle growth in a coastal upwelling system
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沿海上升流系统中藤壶生长的时空变化
DOI：
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发表时间：
2001
期刊：
影响因子：
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通讯作者：
B. Menge
中科院分区：
文献类型：
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作者：
E. Sanford;B. Menge
最近的研究表明，近岸初级生产力的大尺度变化可能强烈影响岩质潮间带群落的动态。在假设的影响中，浮游植物丰度与藤壶和其他悬浮食性动物的生长之间存在联系。我们通过定量测定水体叶绿素a （chl a）浓度和2种潮间带藤壶（Balanus glandula和Chthamalus dalli）的生长，在美国俄勒冈州中部海岸测试了这种关联的强度。在俄勒冈州草莓山（SH）和锅炉湾（BB）两个近岸生产力不同的地点，每隔13天在波浪暴露和波浪保护的栖息地上的潮间带生长板上拍摄藤壶。B.腺藻在波浪暴露的地区比波浪保护的栖息地生长得更快，可能是因为更高的水流给被动进食的藤壶提供了更多的食物。几个月后，这两个物种的个体在chl - a浓度持续较高的SH处都达到了较大的尺寸。令人惊讶的是，浮游植物的短期生长速率仅部分与时空变化相匹配。在持续的上升流期间，增长率很低，在随后的上升流放松期间，增长率增加了2- 3倍。在SH，这种增长与浮游植物的主要繁殖相吻合，但在chl a浓度下降后，生长速度仍然很高。此外，在BB观察到生长的平行增长，尽管在该地点没有记录到开花。这些结果表明，除了浮游植物外，其他因素对藤壶生长的变化也有影响。藤壶沉降记录表明，在藤壶高生长时期，两个地点的水柱中幼虫浓度急剧增加。发表的对胃内容物的分析表明，浮游动物可能是其他藤壶物种的重要食物来源。然而，另一个因素，水温，也在藤壶持续生长期间升高。因此，在上升流放松期间，藤壶生长的增加可能是由于更多的浮游植物、更多的浮游动物和更温暖的水温的综合好处。将浮游动物和水温的影响纳入自下而上影响的研究中，可能会提高我们解释潮间带群落变化的能力。
Recent studies suggest that large-scale variation in nearshore primary productivity may strongly influence the dynamics of rocky intertidal communities. Among the hypothesized effects is a link between phytoplankton abundance and the growth of barnacles and other suspension feeders. We tested the strength of this association on the central coast of Oregon, USA, by quantifying water- column chlorophyll a (chl a) concentration and the growth of 2 intertidal barnacles (Balanus glandula and Chthamalus dalli). Barnacles were photographed at 13 d intervals on mid-intertidal growth plates attached in wave-exposed and wave-protected habitats at 2 sites differing in nearshore pro- ductivity: Strawberry Hill (SH) and Boiler Bay (BB), Oregon. B. glandula grew more rapidly in wave- exposed areas than wave-protected habitats, presumably because higher flows delivered more food to passively feeding barnacles. After several months, individuals of both species attained a larger size at SH, the site with consistently higher chl a concentrations. Surprisingly, short-term growth rates only partially matched spatial and temporal variations in phytoplankton. Growth rates were low dur- ing a persistent upwelling event, and increased 2- to 3-fold during the subsequent upwelling relax- ation. At SH, this increase coincided with a major phytoplankton bloom, but growth rates remained high well after chl a concentrations decreased. Moreover, parallel increases in growth were observed at BB, despite the fact that no bloom was recorded at this site. These results imply that factors other than phytoplankton contributed to variation in barnacle growth. Records of barnacle settlement sug- gest that water-column concentrations of larvae increased dramatically at both sites during the period of high barnacle growth. Published analyses of stomach contents indicate that zooplankton may be an important food source in other barnacle species. Yet another factor, water temperature, was also elevated during the period of sustained barnacle growth. Increased barnacle growth during the upwelling relaxation may thus have arisen from the combined benefits of more phytoplankton, more zooplankton, and warmer water temperatures. Incorporating the influence of zooplankton and water temperature into studies of bottom-up influences may improve our ability to explain variation among intertidal communities.