The Oceans Institute and School of Plant Biology, Faculty of Natural and Agricultural Science, The University of Western Australia, Perth, Western Australia, Australia.
PLoS One. 2012;7(6):e39634. doi: 10.1371/journal.pone.0039634. Epub 2012 Jun 25.
The implications of shallow water impacts such as fishing and climate change on fish assemblages are generally considered in isolation from the distribution and abundance of these fish assemblages in adjacent deeper waters. We investigate the abundance and length of demersal fish assemblages across a section of tropical continental shelf at Ningaloo Reef, Western Australia, to identify fish and fish habitat relationships across steep gradients in depth and in different benthic habitat types. The assemblage composition of demersal fish were assessed from baited remote underwater stereo-video samples (n = 304) collected from 16 depth and habitat combinations. Samples were collected across a depth range poorly represented in the literature from the fringing reef lagoon (1-10 m depth), down the fore reef slope to the reef base (10-30 m depth) then across the adjacent continental shelf (30-110 m depth). Multivariate analyses showed that there were distinctive fish assemblages and different sized fish were associated with each habitat/depth category. Species richness, MaxN and diversity declined with depth, while average length and trophic level increased. The assemblage structure, diversity, size and trophic structure of demersal fishes changes from shallow inshore habitats to deeper water habitats. More habitat specialists (unique species per habitat/depth category) were associated with the reef slope and reef base than other habitats, but offshore sponge-dominated habitats and inshore coral-dominated reef also supported unique species. This suggests that marine protected areas in shallow coral-dominated reef habitats may not adequately protect those species whose depth distribution extends beyond shallow habitats, or other significant elements of demersal fish biodiversity. The ontogenetic habitat partitioning which is characteristic of many species, suggests that to maintain entire species life histories it is necessary to protect corridors of connected habitats through which fish can migrate.
浅水撞击（如捕鱼和气候变化）对鱼类组合的影响通常被孤立考虑，而不考虑这些鱼类组合在相邻较深水域中的分布和丰度。我们在澳大利亚西部宁加洛珊瑚礁的一个热带大陆架部分调查了底栖鱼类组合的丰度和长度，以确定鱼类和鱼类栖息地在深度和不同底栖生境类型的陡峭梯度上的关系。从诱饵远程水下立体视频样本（n = 304）评估底栖鱼类的组合组成，这些样本是从 16 个深度和生境组合中收集的。样本采集范围从文献中很少代表的边缘礁泻湖（1-10 米深）到前礁坡到礁底（10-30 米深），然后到相邻的大陆架（30-110 米深）。多元分析表明，存在独特的鱼类组合，并且不同大小的鱼类与每个生境/深度类别相关。物种丰富度、MaxN 和多样性随深度下降，而平均长度和营养水平增加。底栖鱼类的组合结构、多样性、大小和营养结构从浅近岸生境转变为更深的水生生境。与其他生境相比，更多的生境专家（每个生境/深度类别独特的物种）与礁坡和礁底相关，但近海以海绵为主的生境和近岸以珊瑚为主的礁也支持独特的物种。这表明，在浅珊瑚为主的礁生境中的海洋保护区可能无法充分保护那些深度分布超出浅生境的物种，或其他重要的底栖鱼类生物多样性元素。许多物种特有的发育生境分区表明，为了维持整个物种的生命历史，有必要保护连接的生境走廊，鱼类可以通过这些走廊迁移。
