Seamount fish communities are susceptible to variations due to the oceanographic conditions and level of historical fishing effort. In the NE Atlantic, the Azores is considered an “oceanic seamount ecosystem area” because seamount concentration is high relative to other regions. Scientific information on seamounts in the Azores remains scarce and demersal fishery occurs mostly without any knowledge to endorse sustainable harvest strategies. To make available an important baseline information on dynamics of demersal fish populations inhabiting commercially exploited seamounts, the present study has as specific objectives to (a) describe the taxonomic composition of demersal fish assemblages on underwater mountains, (b) examine whether assemblages vary spatial and temporally, and (c) investigate what drives distributional patterns of species in terms of abundance and size composition. For this, three Azorean seamounts (Açores, Princesa Alice and Mar da Prata) exploited by bottom fishing were selected as case study areas. Data were obtained from scientific surveys and commercial fishery over the past c. 25 years. A total of 84 species from 45 families were identified. Sebastidae, Moridae, Sparidae and Centrophoridae were the most abundant families, mainly represented by Helicolenus dactylopterus, Mora moro, Pagellus bogaraveo and Deania profundorum, respectively. Fish assemblages were more distinguishable spatially than temporally. Depth was identified as the main factor responsible for these differences. The higher occurrence of shallow and intermediate (i.e., up to 600 m) habitats in Princesa Alice and Açores seems to favor the occurrence of a greater number of species and higher abundances in comparison to Mar da Prata. Phycis phycis, Pontinus kuhlii, H. dactylopterus, P. bogaraveo, Conger conger and M. moro were the species which primarily contributed to dissimilarities in assemblage structure among sample groups. Abundance indices and fish sizes showed a decreasing trend for many of these species, especially for those with sedentary behaviour inhabiting historically highly exploited seamount areas. These results highlighted the vulnerability of demersal fishes to the expansion of fishing effort in the offshore seamount areas. Spatial management of seamounts should be a priority being fish conservation balanced with strategies that support sustainable fisheries.

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在亚速尔群岛（东北大西洋）捕鱼开发的海山上的海底鱼类组合

由于海洋条件和历史捕捞努力水平，海山鱼类群落容易发生变化。在东北大西洋，亚速尔群岛被认为是“海洋海山生态系统区”，因为相对于其他地区，海山集中度很高。关于亚速尔群岛海山的科学信息仍然匮乏，沉没式渔业大多在没有任何知识支持可持续捕捞策略的情况下发生。为了提供有关居住在商业开发的海山上的沉鱼种群动态的重要基线信息，本研究的特定目标是（a）描述水下山区的沉鱼组合的分类学组成，（b）检查这些组合在空间和空间上是否变化在时间上，（c）从丰度和大小组成方面研究驱动物种分布模式的因素。为此，选择了由底钓开发的三个亚速尔群岛海山（亚速尔群岛，爱丽丝公主和玛尔达·普拉塔）作为案例研究区域。数据来自过去的科学调查和商业渔业c。25年。共鉴定了来自45个科的84种。Sebastidae，Moridae，Sparidae和Centrophoridae是最丰富的科，主要以Helicolenus dactylopterus，Mora moro，Pagellus bogaraveo和Deania profundorum为代表。鱼群在空间上比在时间上更具区分性。深度被确定为造成这些差异的主要因素。与玛尔达·普拉塔（Mar da Prata）相比，Princesa Alice和Açores的浅层和中层（最高600 m）生境的发生率更高，似乎更有利于出现更多种类的物种和更高的丰度。褐鳕，海鮋属kuhlii，Dactylopterus，P. bogaraveo，Conger conger和M. moro是主要导致样品组间组装结构差异的物种。这些物种中的许多物种的丰度指数和鱼类尺寸呈下降趋势，特别是对于那些长期居住在历史高度开发的海山地区的久坐行为的物种。这些结果突显了深海鱼类对扩大近海海山地区捕捞努力的脆弱性。海山的空间管理应作为优先重点，即在鱼类保护与支持可持续渔业的战略之间取得平衡。