What limits secondary production in the estuaries of snowmelt-dominated basins? Due to substantial differences in their annual hydrographs, zooplankton dynamics in these estuaries are expected to differ from better-studied pluvial systems. We hypothesized that water residence time limited zooplankton production in the undammed, snowmelt-dominated estuary of the Fraser River, Canada. We sampled zooplankton and associated environmental variables bi-weekly to monthly in slough and channel areas of the estuary over a 33-month period. Annual mean copepod abundance at channel stations was low (2005 ± 238 ind. m⁻³) in comparison to other studied estuaries, with minima occurring during spring, concurrent with the freshet. Higher abundances (11,905 ± 3606 ind. m⁻³) observed at slough stations were attributed to estuarine copepods. Differences in abundance and species composition between slough and channel areas, and the coincidence of seasonal minima with the freshet, suggest that the low water residence time of this system limits zooplankton density and production. Heavy channelization of the Fraser River Estuary has further reduced water residence time in the estuary, likely affecting prey availability to fish and invertebrate predators. Given that peak river discharge in snowmelt-dominated basins occurs during the relatively short spring-summer growing season, the impacts of channelization on zooplankton production in the estuaries of snowmelt-dominated basins may be greater than in river-dominated estuaries subjected to different flow regimes.

中文翻译：

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以雪融为主的河口中的pe足类动物组装动力学

是什么限制了融雪为主的盆地河口的二次生产？由于它们的年度水文图存在实质性差异，因此预计这些河口中的浮游动物动力学与研究较好的河流系统不同。我们假设水停留时间限制了加拿大弗雷泽河未受阻，融雪为主的河口浮游动物的生产。我们在33个月的时间内，每两周至每月一次在河口的泥沼和航道区域取样浮游动物和相关的环境变量。与其他研究河口相比，河槽站的年co足类年平均丰度较低（2005±238 ind。m ^-3），春季和春季期间均出现极小值。更高的丰度（11,905±3606 ind。m ^-3在泥沼站观察到的）归因于河口co足类动物。泥沼和河道区域之间的丰度和物种组成的差异，以及季节性极小值与鲜食的重合，表明该系统的低水位停留时间限制了浮游动物的密度和产量。弗雷泽河河口的沉重河道化进一步减少了河口中的水停留时间，这可能会影响鱼类和无脊椎动物天敌的猎物可利用性。鉴于融雪融汇盆地的河道洪峰高峰出现在相对较短的春夏季生季节，因此在融雪融化盆地的河口，渠道化对浮游动物生产的影响可能要大于在不同水流条件下的河流融化河口。 。