Waterhyacinth [Eichhornia crassipes (Mart.) Solm] is an aquatic invasive plant that is widespread in Puerto Rico, where it negatively effects estuaries, freshwater wetlands, potable water reservoirs, and wildlife refuges. Specifically, the tropical estuary San Juan Bay Estuary (SJBE) has been impacted with the presence of E. crassipes. Infestations have led to a reduction of water circulation in the system and have facilitated the establishment of invasive fauna. Therefore, a field study was conducted in a cove between Laguna San Jose and Peninsula Cantera to assess the use of glyphosate and hand removal as a management tool for E. crassipes control. Aquatic macroinvertebrates and water quality were also monitored as a measure of environmental impact due to management activities. Results indicated that at 2 wk after glyphosate application, E. crassipes biomass (dry weight) was significantly reduced to 0.27 kg DW m−2 at the treated plot compared with the nontreated plot, which yielded 0.62 kg DW m−2. Fresh weight of E. crassipes decreased more than 90% when hand removal was used compared with glyphosate treatment. Dissolved oxygen and water pH were not significantly different between sites; however, water salinity increased to 8 to 9 ppt at both plots as a result of tidal activity. The order Hemiptera followed by Sarcoptiformes were common in the aquatic macroinvertebrate community. Macroinvertebrate species found associated with E. crassipes and considered natural enemies were: Orthogalumna terebrantis Wallwork, Niphograpta albigutalis (Warren), and Neochetina eichhorniae Warner. The use of glyphosate to manage E. crassipes at the Laguna San Jose was useful as a short-term control method, and its efficacy may be enhanced over time with follow-up applications in combination with hand removal.

中文翻译：

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波多黎各使用草甘膦和手部去除水葫芦（凤眼莲）控制的案例研究

水葫芦 [凤眼莲(Mart.) Solm] 是一种水生入侵植物，广泛分布于波多黎各，对河口、淡水湿地、饮用水水库和野生动物保护区产生负面影响。具体来说，热带河口圣胡安湾河口 (SJBE) 受到影响E. crassipes. 虫害导致系统中的水循环减少，并促进了入侵动物群的建立。因此，在圣何塞拉古纳和坎特拉半岛之间的一个海湾进行了一项实地研究，以评估草甘膦和除手作为管理工具的使用情况E. crassipes控制。还监测水生大型无脊椎动物和水质，作为管理活动对环境影响的衡量标准。结果表明，在草甘膦施用后 2 周，E. crassipes生物量（干重）显着降低至 0.27 kg DW m-2处理地块与未处理地块相比，产生 0.62 kg DW m-2. 鲜重E. crassipes与草甘膦处理相比，用手去除时减少了 90% 以上。溶解氧和水的 pH 值在不同地点之间没有显着差异；然而，由于潮汐活动，两个地块的水盐度增加到 8 到 9 ppt。在水生大型无脊椎动物群落中，半翅目和肉形目很常见。发现与相关的大型无脊椎动物物种E. crassipes被认为是天敌：原虫墙饰，白蛉（沃伦），和凤眼莲华纳。草甘膦的使用管理E. crassipes在圣何塞拉古纳，作为一种短期控制方法是有用的，随着时间的推移，它的功效可能会随着后续应用结合手部去除而增强。