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The assessment of population structure and abundance of fish assemblages associated with artificial reefs(ARs) is an important aspect of AR management.In the present study,we used a DiveOperated Stereo Video(stereo-DOV) technique to assess the population structure and abundance of Sebastes schlegeli associated with two metallic,and three wooden,vessel reefs in Haizhou Bay during 2012 and2013.The study used video systems to obtain length measurements and estimates of abundance.The size composition of S.schlegeli differed among reefs and individuals around vessel reefs were all adults,with total lengths(TL) of 20 cm.Juvenile fish were encountered by divers in a rocky area near the island away from the vessel reefs.The largest individual S.schlegeli(with the highest TL) among five reefs were found around a metallic vessel reef in both 2012 and 2013.TL of S.schlegeli from all reefs increased by an average of 3.2 cm(P0.05) from 2012 to 2013,with an estimated mean weight increase of 250.4 g(P0.05).The video survey also indicated a decrease in the biomass of schools near two metallic vessels between the years.Stereo-video technology was found to be suitable for rockfish surveys around the reefs. 相似文献
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2004和2007年春季长江口近海鱼类群落特征及其与环境因子的关系 总被引：2，自引：0，他引：2
根据2004年5月和2007年5月长江口近海渔业资源调查数据,应用双向指示种分析(TWINSPAN)和典范对应分析(CCA)方法,分析了春季长江口鱼类群落特征,探讨了春季长江口鱼类群聚结构及其与环境因子的关系。结果表明,2个春季航次共捕获鱼类生物9目25科36种,其中带鱼(Trichiurus lepturus)、黄鲫(Setipinna taty)、鳀(Engraulis japonicas)、竹荚鱼(Trachurus japonicas)、小黄鱼(Larimichthys polyactis)和鲐(Scomber japonicas)为优势种。2004和2007年长江口近海鱼类存在4个生物群聚:以鲐为特征种的南部高温型、以带鱼为优势种的南部低温型、以竹荚鱼为代表的北部高温型和以黄鲫占绝对优势的北部低温型。影响2004和2007年长江口海域鱼类分布的主要环境因子为水深、底层总磷、表层悬浮体含量、底层盐度和表层温度。其中,水深、盐度和悬浮体含量驱动鱼类群聚空间变异,温度驱动了时间变异。与1999—2001年相比较,2004和2007年长江口鱼类群落发生显著变异,鱼类资源种类数量和生物量减少,优势种亦发生演替;水深、盐度、温度变异对鱼类群聚分布保持影响力,水域悬浮体含量成为鱼类群聚空间变异的重要驱动因素。 相似文献
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杨村煤矿二、四采区奥灰水放水试验及数值模拟分析 总被引：3，自引：1，他引：2
为防止杨村煤矿下组煤开采时发生底板突水事故,本文利用井下现有的水文地质观测孔,对奥陶系灰岩含水层进行了现场小型放水试验,并应用GMS软件模拟了地下水流场以获得水文地质参数。结果表明,奥灰水与十三～十四灰水在天然状态下无直接的水力联系,建议对十三～十四灰水采取疏水降压方式,对奥灰水采用避让措施,发现导水通道要及时进行处理。 相似文献
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