Carbon sources supporting a diverse fish community in a tropical coastal ecosystem (Gazi Bay, Kenya)
Carbon sources supporting a diverse fish community in a tropical coastal ecosystem (Gazi Bay, Kenya)
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DOI：
10.1016/j.ecss.2009.01.009
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发表时间：
2009-07-10
影响因子：
2.8
通讯作者：
Bouillon, S.
中科院分区：
文献类型：
--
作者：
Nyunja, J.;Ntiba, M.;Bouillon, S.
相互关联的红树林-海草生态系统是许多热带沿海地区的特征，是各种鱼类和无脊椎动物的觅食和繁殖地。在加齐湾（肯尼亚）的三个地点对支持渔业的自养碳源进行了研究，其中两个地点位于流经大片红树林的潮汐小溪中，另一个地点位于潮下海草草甸，距森林约 2.5 公里。分析了 42 种鱼类、2 种甲壳类动物和一系列潜在主要食物来源（例如红树林、海草和附生植物、大型藻类）的碳和氮稳定同位素组成。鱼类（-16.1 +/- 2.17 份/千）、海草（-15.1 +/- 3.07 份/千）、海草附生植物（-13.6 +/- 3.3 份/千）和大型藻类（-20.4 +/- 3.1 份/千）之间的 delta(13)C 特征存在相当大的重叠。然而，大多数初级生产者的特征足够明显，表明鱼类的主要碳源主要来自海草及其相关的附生群落，也可能来自大型藻类。红树林产生的有机物质对整个鱼类食物网的贡献很小。支持这些鱼类群落的碳是直接通过草食性和一些杂食性鱼类的放牧获得的，或者间接通过底栖食物网获得的。与在邻近海草床中收集的鱼类（-14.7 +/- 1.77 ppm）相比，来自红树林小溪的鱼类具有明显较低的 delta(13) C 特征（-16.8 +/- 2.0 ppm）。这表明这些栖息地被用作所收集鱼类的独特庇护和摄食区，尽管鱼类群落内有规律的运动模式，但其内部交换程度极低。 (C) 2009 Elsevier Ltd. 保留所有权利。
Interlinked mangrove-seagrass ecosystems are characteristic features of many tropical coastal areas, where they act as feeding and nursery grounds for a variety of fishes and invertebrates. The autotrophic carbon sources supporting fisheries in Gazi bay (Kenya) were studied in three sites, two located in the tidal creeks flowing through extensive mangrove forests, another site located in the subtidal seagrass meadows, approximately 2.5 km away from the forest. Carbon and nitrogen stable isotope composition of 42 fish species, 2 crustacean species and a range of potential primary food sources (e.g., mangroves, seagrasses and epiphytes, macroalgae) were analysed. There was considerable overlap in the delta(13)C signatures between fish (-16.1 +/- 2.17 parts per thousand), seagrasses (-15.1 +/- 3.07 parts per thousand), seagrass epiphytes (-13.6 +/- 3.3 parts per thousand), and macroalgae (-20.4 +/- 3.1 parts per thousand). Nevertheless, the signatures for most primary producers were sufficiently distinct to indicate that the dominant carbon sources for fish were mainly derived from the seagrass and their associated epiphytic community, and possibly macroalgae. Mangrove-derived organic matter contributes only marginally to the overall fish food web. Carbon supporting these fish communities was derived directly through grazing by herbivorous and some omnivorous fishes, or indirectly through the benthic food web. Fishes from the mangrove creeks had distinctly lower delta(13)C signatures (-16.8 +/- 2.0 parts per thousand) compared to those collected in the adjacent seagrass beds (-14.7 +/- 1.77 parts per thousand). This indicated that these habitats were used as distinct sheltering and feeding zones for the fishes collected, with minimal degree of exchange within the fish communities despite their regular movement pattern. (C) 2009 Elsevier Ltd. All rights reserved.