Lake St Lucia, the largest estuarine lake system in Africa, has been closed since 2002 except for a five month period in 2007 when the mouth was breached by an episodic event, Cyclone Gamede. Mouth opening in 2007 was preceded by five years of low lake levels and hypersaline conditions, which changed the fish species composition and greatly reduced marine fish species diversity. Mouth opening in March 2007 caused the system to partially fill and marine salinities were restored, allowing recruitment of marine species. This study assessed changes in the fish community during the period 2008–2011 following mouth closure after the Cyclone Gamede breaching event. A total of 19,726 fish representing 61 species were collected using seine netting at six sites across the system during biannual sampling between 2008 and 2011. After mouth closure in August 2007, salinities increased and North Lake became hypersaline during 2009–2010. Marine species initially dominated in terms of species number, but freshwater and estuarine species became progressively more abundant, notably Oreochromis mossambicus and Ambassis ambassis. The number of species decreased from 51 in 2008 to 37 in 2011, with 22 marine and two estuarine species being lost from the system. The abundance of marine species decreased by >75% as the system became progressively more saline and the closed mouth limited recruitment to infrequent overtopping events. Changes in the fish community were largely driven by salinity changes across the three main regions of the system. Although management efforts to increase freshwater inflow from the Mfolozi estuary was successful, rapid siltation of the mouth area is a concern.

非洲最大的河口湖泊圣卢西亚湖自2002年以来一直关闭，除了2007年的五个月期间因一次偶发性事件飓风加米德（Cyclone Gamede）破坏了该河口外。在2007年张开嘴之前，是五年的低湖水位和高盐条件，这改变了鱼类的组成并大大降低了海洋鱼类的多样性。2007年3月的张口使该系统部分充满，并且恢复了海洋盐度，从而可以招募海洋物种。这项研究评估了2008-2011年气旋Gamede破坏事件后闭口后鱼类群落的变化。在2008年至2011年之间的两年一次抽样中，使用围网在系统的六个站点上收集了代表61种鱼的19,726条鱼。在2007年8月闭口后，盐度增加，北湖在2009–2010年间变成高盐度。海洋物种最初在物种数量上占主导地位，但淡水和河口物种逐渐变得更加丰富，特别是莫桑比克罗非鱼（Oreochromis mossambicus）和大使大使（Ambasssis ambassis）。该物种的数量从2008年的51种减少到2011年的37种，其中22种海洋和两种河口物种从该系统中消失。随着系统逐渐变得含盐量增加，海洋物种的丰富度减少了> 75％，并且闭口将招募限于罕见的超车事件。鱼类群落的变化主要是由系统三个主要区域的盐度变化驱动的。尽管增加Mfolozi河口淡水流入量的管理工作取得了成功，但令人担忧的是口区的快速淤积。