CRB: Faunal Attenuation: Predicting Spatial and Temporal Dynamics of Refugia in the Lake Victoria Basin

外来物种进入新的栖息地对当地物种有负面影响，包括被引入的捕食者对当地物种的捕食。在非洲乌干达的维多利亚湖，据估计，在过去的15年里，400多种本地鱼类中有50%显然已经消失。一个可能的原因是引进的尼罗河鲈鱼的捕食。以前的研究已经确定湿地是保护一些鱼类免受尼罗河鲈鱼捕食的重要避难所。这些避难所可能含氧量低，结构复杂，通过抑制栖息扩散到湿地来保护适应的鱼类。这一建议的目标是：1)建立泻湖避难所鱼类物种丰富度和多样性的预测模型；2)通过实地采样和古水文学技术检查泻湖鱼类群落的变化；3)将从小型泻湖避难所得出的预测应用于较大的卫星湖泊；以及4)研究湿地的物理结构和氧气浓度如何影响尼罗河鲈鱼和猎物物种在泻湖的定居。避难所的识别和保护已成为当地动物生存的关键。这项研究将有助于确定避难所的特征，这些避难所是残存人口的港湾，也是限制或允许使用避难所的地方。主要调查人员解决的维多利亚湖流域的问题与许多湿地地区鱼类的养护有关，并对许多系统中动物残留物的保护具有更广泛的影响，在这些系统中，分类群存活在小块孤立的斑块中。

The introduction of exotic species into new habitats has negative effects on native species including predation on native species by introduced predators. In Lake Victoria, Uganda, Africa an estimated 50% of the 400+ native species of fishes have apparently disappeared in the last 15 years. One possible cause is predation by the introduced Nile perch, Lates niloticus. Previous studies have identified wetlands as important refuges protecting some fishes from Nile perch predation. These refugia may have low oxygen levels and structural complexity that protects adapted fishes by inhibiting perch dispersal into the wetlands. The objectives of this proposal are to 1) develop a predictive model of fish species richness and diversity for lagoon refugia; 2) examine the changes of fish communities in lagoons through field sampling and paleolimnological techniques; 3) apply predictions derived from small lagoon refugia to larger satellite lakes; and 4) examine how physical structure and oxygen concentration of wetlands affects lagoon colonization by Nile perch and prey species. The identification and protection of refugia has become critical to the survival of native fauna. This study will help identify characteristics of refugia that harbor remnant populations and that limit or permit use of refugia. The problems in the Lake Victoria Basin addressed by the principal investigators are relevant to the conservation of fishes in many wetland regions and have broader implications for the conservation of faunal remnants in many systems where taxa survive in small isolated patches.