PATTERNS OF FISH AND URCHIN GRAZING ON CARIBBEAN CORAL REEFS - ARE PREVIOUS RESULTS TYPICAL
PATTERNS OF FISH AND URCHIN GRAZING ON CARIBBEAN CORAL REEFS - ARE PREVIOUS RESULTS TYPICAL
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DOI：
10.2307/1941407
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发表时间：
1984-01-01
期刊：
影响因子：
4.8
通讯作者：
HAY, ME
中科院分区：
文献类型：
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作者：
HAY, ME
在一项野外生物测定中，研究人员利用海草条来评估散布在加勒比地区的11个珊瑚礁的食草性。将海地和美属维尔京群岛过度捕捞珊瑚礁上的草食模式与7个捕捞较少的珊瑚礁（美属维尔京群岛、巴拿马、洪都拉斯、伯利兹和巴哈马）的模式进行了比较。在过度捕捞的珊瑚礁上，随着深度的增加，Thalassia的去除率显著增加，海胆密度高，海胆放牧等于或大于浅生境（< 10 m深）的鱼类放牧。在捕捞压力较小的珊瑚礁上，海藻类的清除率随深度的增加而降低，海胆密度低，草食性鱼类几乎承担了所有的海藻类清除。先前评估加勒比海地区海胆放牧重要性的研究是在过度捕捞的珊瑚礁上进行的，那里的海胆密度异常高，而食草鱼类的密度异常低。在这些被大量捕捞的珊瑚礁上观察到的海胆-藻类和海胆-珊瑚相互作用的强度是否发生在未受人类影响的珊瑚礁上，这是值得怀疑的。
Strips of the seagrass Thalassia testudinum were used in a field bioassay to assess herbivory on 11 coral reefs scattered throughout the Caribbean. Patterns of herbivory on overfished reefs in Haiti and the USA Virgin Islands were compared to patterns on 7 less fished reefs (USA Virgin Islands, Panama, Honduras, Belize and the Bahamas). On the overfished reefs, the rate of Thalassia removal increased significantly with depth, urchin densities were high, and urchin grazing was equal to, or greater than, fish grazing in shallow (< 10 m deep) habitats. On reefs subject to little fishing pressure, the rate of Thalassia removal decreased with depth, urchin densities were low, and herbivorous fishes were responsible for almost all Thalassia removal. Previous studies assessing the importance of urchin grazing in the Caribbean have been conducted on overfished reefs where urchin densities were unusually high and the density of grazing fish unusually low. It is doubtful that the intensity of urchin-algal and urchin-coral interactions observed on these heavily fished reefs occurs on reefs unaffected by humans.