Effects of bottom-layer hypoxia on abundances and depth distributions of organisms in Patuxent River, Chesapeake Bay
Effects of bottom-layer hypoxia on abundances and depth distributions of organisms in Patuxent River, Chesapeake Bay
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DOI：
10.3354/meps205043
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发表时间：
2000-10
影响因子：
2.5
通讯作者：
J. Keister;E. Houde;D. Breitburg
中科院分区：
文献类型：
--
作者：
J. Keister;E. Houde;D. Breitburg
氧气消耗，季节性常见的底层沃茨的许多分层的水生系统，可能有强烈的影响，丰度，分布和生物之间的相互作用，因此社区动态。为了研究底层缺氧的影响，密度和垂直分布在一个分层的subestuary，鱼苗，他们的凝胶状捕食者，桡足类的猎物进行了调查近表面，密度跃层内，近底在Patuxent河（切萨皮克湾）的范围内的近底溶解氧（DO）的条件。当底层DO较低（≤2 mg DO 1 - 1）时，整个水体中鱼类幼虫和桡足类无节幼体的总体丰度较低。当底层DO较低（2 mg 1 - 1）时，桡足类无节幼体的总密度下降> 50%。几种生物的深度分布也受到底部缺氧的影响：当底层DO低于2 mg 1 - 1时，靠近底部的仔鱼、钵水母和桡足类的数量要少得多。当溶解氧浓度低至1.3mg·1 - 1时，莱迪拟记忆水母的出现密度较高，但当溶解氧浓度低于1 mg·1 - 1时，莱迪拟记忆水母几乎消失。结果表明，潜在的重大差异，在生物体的相互作用，特别是捕食者-被捕食者的关系，之间的时间的高和低底层DO。
Oxygen depletion, seasonally common in bottom waters of many stratified aquatic systems, may have strong effects on abundances, distributions, and interactions among organisms, and therefore community dynamics. To examine effects of bottom-layer hypoxia on densities and vertical distributions in a stratified subestuary, fish larvae, their gelatinous predators, and copepod prey were surveyed near-surface, within the pycnocline, and near-bottom in the Patuxent River (Chesapeake Bay) under a range of near-bottom dissolved oxygen (DO) conditions. Overall abundances of fish larvae and copepod nauplii were lower throughout the water column when bottom-layer DO was low (≤2 mg DO 1 -1 ). When bottom-layer DO was low ( 2 mg 1 -1 ) DO conditions, and overall density of copepod nauplii declined by >50%. Depth-distributions of several organisms also were affected by bottom-oxygen depletion: fish larvae, scyphomedusae, and copepods were much less common near the bottom when bottom-layer DO was low than when it was >2 mg 1 -1 . The ctenophore Mnemiopsis leidyi occurred in high densities at DO as low as 1.3 mg 1 -1 , but was nearly absent at <1 mg 1 -1 . The results indicate the potential for substantial differences in organism interactions, especially predator-prey relationships, between times of hiqh and low bottom-layer DO.