ABSTRACT: Changes in fish communities as oceans warm and cool and competition for space between established and novel species can be evaluated in biogeographic transition zones such as the west coast of Australia. At ~30° S in this region, a cool anomaly occurred in the 2000s, between marine heatwaves. Over 2 yr of that anomaly, surveyed reef fishes were 57% temperate, 18% sub-tropical and 25% tropical. The most numerous fishes included a wrasse, herring, bullseye, drummer and damselfish. Based on similarities in the composition of fishes, 7 significant clusters of reefs were identified along a gradation from deep, exposed reefs to shallow, protected lagoonal reefs. Endemic sub-tropical and temperate wrasses and damselfishes typified all reefs. Some of these were ubiquitous over exposed and lagoonal reefs and others prevalent in only one reef type, demonstrating habitat preferences and partitioning among closely related species. This was reflected in the differing order of importance of fishes that typified different reefs. Linear modelling indicated that abiotic (depth, distance from shore) and biotic factors (e.g. algae) explained most of the variation in the fish communities among reefs. Additional variation, particularly within lagoonal reefs, was related to relief, turf and corals, rather than water temperature. Occurrence and reproductive activity of a group of tropical/sub-tropical wrasses and damselfish in some lagoonal reefs with abundant tropical habitats (e.g. corals) suggested that they supported novel communities during cool anomalies. Better predictions of future change and interactions between existing and novel species with environmental cycles requires knowledge of species-specific habitat relationships and biology.

中文翻译：

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温带、亚热带和热带鱼类海洋过渡带珊瑚礁的划分与深度和栖息地的关系比与温度有关

摘要：在澳大利亚西海岸等生物地理过渡区，可以评估随着海洋变暖和变冷以及现有物种和新物种之间的空间竞争而导致的鱼类群落变化。在该地区约 30° S，2000 年代海洋热浪之间发生了凉爽的异常现象。在超过 2 年的异常情况下，调查的珊瑚礁鱼类 57% 是温带的，18% 是亚热带的，25% 是热带的。数量最多的鱼类包括濑鱼、鲱鱼、靶心、鼓手和雀鲷。根据鱼类组成的相似性，沿着从较深的裸露珊瑚礁到浅层受保护的泻湖珊瑚礁的等级确定了 7 个重要的珊瑚礁群。地方性亚热带和温带濑鱼和雀鲷是所有珊瑚礁的典型代表。其中一些在裸露的泻湖珊瑚礁上无处不在，而另一些则仅在一种珊瑚礁类型中普遍存在，展示栖息地偏好和密切相关物种之间的划分。这反映在代表不同珊瑚礁的鱼类重要性的不同顺序上。线性模型表明，非生物（深度、离岸距离）和生物因素（例如藻类）解释了珊瑚礁之间鱼类群落的大部分变化。其他变化，特别是在泻湖珊瑚礁内，与地貌、草皮和珊瑚有关，而不是与水温有关。一些热带/亚热带濑鱼和雀鲷在一些热带栖息地（例如珊瑚）丰富的泻湖礁中的发生和繁殖活动表明它们在凉爽的异常时期支持新的群落。