PDF(Pubmed)
Abstract：
Semi-enclosed seas are often associated with elevated local threats and distinct biogeographic patterns among marine fishes, but our understanding of how fish assemblage dynamics vary in relation to relatively small semi-enclosed seas (e.g., the Gulf of Aqaba) remains limited. Baited remote underwater video surveys (n = 111) were conducted across ~300 km of coral reef habitats in the Gulf of Aqaba and the northern Red Sea. A total of 55 predatory fish species were detected, with less than half of all species (n = 23) observed in both basins. Relative abundance patterns between the Gulf of Aqaba and the northern Red Sea were variable among taxa, but nearly twice as many predatory fish were observed per unit of effort in the northern Red Sea. In general, assemblages in both basins were dominated by three taxa (Epinephelinae, Carangidae, and Lethrinidae). Large-bodied and threatened species were recorded at very low abundances. Multivariate analysis revealed distinct assemblage structuring of coral reef predators between the Gulf of Aqaba and the northern Red Sea. Most of the species driving these differences were recorded in both basins, but occurred at varying levels of abundance. Environmental factors were largely unsuccessful in explaining variation in assemblage structuring. These findings indicate that biological assemblages in the Gulf of Aqaba are more distinct than previously reported and that reef fish assemblage structuring can occur even within a relatively small semi-enclosed sea. Despite inter-basin assemblage structuring, the overall low abundance of vulnerable fish species is suggestive of overexploitation in both the Gulf of Aqaba and the northern Red Sea of Saudi Arabia. As the region surveyed is currently undergoing large-scale coastal development, the results presented herein aim to guide spatial management and recovery plans for these coral reef systems in relation to this development.
摘要：
半封闭的海洋通常与海洋鱼类之间的局部威胁和独特的生物地理模式有关，但是我们对鱼类组合动态相对于相对较小的半封闭海的理解(例如，亚喀巴湾）仍然有限。在亚喀巴湾和红海北部约300公里的珊瑚礁栖息地进行了有诱饵的远程水下视频调查（n=111）。共检测到55种掠食性鱼类,在两个盆地中观察到的所有物种（n=23）不到一半。亚喀巴湾和红海北部之间的相对丰度模式在分类单元之间是可变的，但是在红海北部，每单位努力观察到的掠食性鱼类数量几乎是其两倍。总的来说,两个盆地的组合都由三个分类单元（Epinephelinae，Carangidae,和Lethrinidae）。大型和受威胁物种的丰度非常低。多变量分析显示，亚喀巴湾和北部红海之间的珊瑚礁捕食者具有明显的组合结构。大多数驱动这些差异的物种都记录在两个盆地中，但发生在不同的丰度水平。环境因素在很大程度上无法解释组合结构的变化。这些发现表明，亚喀巴湾的生物组合比以前报道的更为独特，即使在相对较小的半封闭海域，礁鱼组合结构也可能发生。尽管存在跨流域组合结构，脆弱鱼类的总体丰度较低，这表明亚喀巴湾和沙特阿拉伯北部红海的过度开发。由于被调查地区目前正在进行大规模的沿海开发,本文提出的结果旨在指导与这一发展相关的这些珊瑚礁系统的空间管理和恢复计划。
