Spatial Patterns of Parrotfish Corallivory in the Caribbean: The Importance of Coral Taxa, Density and Size
Spatial Patterns of Parrotfish Corallivory in the Caribbean: The Importance of Coral Taxa, Density and Size
复制标题
加勒比地区鹦嘴鱼珊瑚食的空间模式：珊瑚类群、密度和大小的重要性
作者：
G. Roff;M. H. Ledlie;J. Ortíz;P. Mumby
过去几十年来，珊瑚礁受到干扰的频率和强度有所增加，导致珊瑚种群的规模和组成发生变化。这些变化导致人们重新关注影响珊瑚种群数量的过程，例如珊瑚食。虽然之前的研究表明珊瑚类群中有选择性的珊瑚食性，但珊瑚大小和珊瑚群密度对影响珊瑚食性的重要性尚不清楚。我们调查了巴哈马群岛内多个空间尺度（岛屿内的珊瑚礁：1-100 公里，岛屿之间：>100 公里）的大小、分类和每个珊瑚群被鹦嘴鱼咬伤的数量，以及三种主要食珊瑚鹦嘴鱼（Sparisoma viride、Sparisoma aurofrenatum、Scarus vetula）的丰度。我们使用线性混合模型来确定珊瑚类群、群体大小、群体密度和鹦嘴鱼丰度对珊瑚食性强度（每平方米珊瑚组织的咬数）的影响。虽然群体密度对确定珊瑚虫的强度有显着影响，但我们发现群体大小或鹦嘴鱼丰度（密度、生物量或群落结构）没有显着影响。鹦嘴鱼咬伤最常见于造礁珊瑚的优势物种（Montastraea permanentis、Montastraea faveolata 和 Porites astreoides），但我们的结果表明，当去除群体密度和大小的混杂影响时，选择性食珊瑚仅存在于次要的 Porites porites 中。由于干扰制度的变化导致主要框架珊瑚（如 Montastraea spp.）的减少，预计加勒比珊瑚礁上滨珊瑚通过高繁殖产量、抗病性和快速生长率所取得的成功可能会因鹦嘴鱼的选择性食珊瑚而减弱。
The past few decades have seen an increase in the frequency and intensity of disturbance on coral reefs, resulting in shifts in size and composition of coral populations. These changes have lead to a renewed focus on processes that influence demographic rates in corals, such as corallivory. While previous research indicates selective corallivory among coral taxa, the importance of coral size and the density of coral colonies in influencing corallivory are unknown. We surveyed the size, taxonomy and number of bites by parrotfish per colony of corals and the abundance of three main corallivorous parrotfish (Sparisoma viride, Sparisoma aurofrenatum, Scarus vetula) at multiple spatial scales (reefs within islands: 1–100 km, and between islands: >100 km) within the Bahamas Archipelago. We used a linear mixed model to determine the influence of coral taxa, colony size, colony density, and parrotfish abundance on the intensity of corallivory (bites per m2 of coral tissue). While the effect of colony density was significant in determining the intensity of corallivory, we found no significant influence of colony size or parrotfish abundance (density, biomass or community structure). Parrotfish bites were most frequently observed on the dominant species of reef building corals (Montastraea annularis, Montastraea faveolata and Porites astreoides), yet our results indicate that when the confounding effects of colony density and size were removed, selective corallivory existed only for the less dominant Porites porites. As changes in disturbance regimes result in the decline of dominant frame-work building corals such as Montastraea spp., the projected success of P. porites on Caribbean reefs through high reproductive output, resistance to disease and rapid growth rates may be attenuated through selective corallivory by parrotfish.