Placer Creek, a tributary of Sangre de Cristo Creek in Colorado's San Luis Valley, supported an allopatric core conservation population of native Rio Grande Cutthroat Trout Oncorhynchus clarkii virginalis during much of the 20th century. After the failure of gabion barriers in the late 1990s, Brook Trout Salvelinus fontinalis infected with Myxobolus cerebralis invaded from Sangre de Cristo Creek. By 2005, whirling disease (WD) and competition from Brook Trout reduced Rio Grande Cutthroat Trout numbers to less than 10% of the total trout population. New barriers were constructed in 2006 and the stream was treated with rotenone in 2007 and 2009 to eliminate all fish prior to the reintroduction of Rio Grande Cutthroat Trout. Results of WD research studies in Montana, California, and Colorado indicated it might be possible to break the life cycle of the parasite in some situations. Our management interventions included (1) reducing the fish population in the stream to zero for approximately 14 months, (2) introducing lineage V and VI Tubifex tubifex worms, which are not susceptible to M. cerebralis, and (3) eliminating a small off-channel pond that provided optimal habitat that sustained a localized high-density population of lineage III T. tubifex, the oligochaete host susceptible to M. cerebralis. Electrofishing during the fall of 2009 and spring of 2010 indicated the drainage was devoid of fish. Fry, juvenile, and adult Rio Grande Cutthroat Trout were stocked in September and October of 2010 and 2011. Approximately 975,000 lineage V and VI T. tubifex were introduced into Placer Creek between 2010 and 2012 as possible oligochaete competitors for the lineage III worms. The off-channel pond was filled in, and the surface was reseeded in April 2012. No evidence of M. cerebralis infection was detected among more than 280 Rio Grande Cutthroat Trout tested between July 2012 and July 2016, indicating the parasite had been eradicated from the Placer Creek basin upstream of the barriers.

中文翻译：

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在Placer Creek（科罗拉多州的本地割喉鳟鱼溪流）中消灭Myxobolus brainis

Placer Creek 是科罗拉多州圣路易斯山谷 Sangre de Cristo Creek 的一条支流，在 20 世纪的大部分时间里，它支持了本地里奥格兰德角鳟鱼 Oncorhynchus clarkii virginalis 的异域核心保护种群。在 1990 年代后期石笼网屏障失效后，感染 Myxobolus brainis 的 Brook Trout Salvelinus fontinalis 从 Sangre de Cristo Creek 入侵。到 2005 年，旋风病 (WD) 和来自布鲁克鳟鱼的竞争将 Rio Grande Cutthroat 鳟鱼数量减少到总鳟鱼种群的 10% 以下。2006 年建造了新的屏障，并在 2007 年和 2009 年用鱼藤酮处理河流，以在重新引入 Rio Grande Cutthroat Trout 之前消灭所有鱼类。WD 在加利福尼亚州蒙大拿州的研究结果，科罗拉多州表示在某些情况下有可能打破寄生虫的生命周期。我们的管理干预措施包括 (1) 在大约 14 个月内将溪流中的鱼类种群减少到零，(2) 引入谱系 V 和 VI Tubifex tubifex 蠕虫，它们对大脑分枝杆菌不敏感，以及 (3) 消除一个小的关闭- 通道池塘提供了最佳栖息地，维持了局部高密度谱系 III T. tubifex 种群，这是一种易受 M. brainis 影响的寡毛纲宿主。2009 年秋季和 2010 年春季的电子捕鱼表明排水系统没有鱼。2010 年 9 月和 10 月和 2011 年放养了鱼苗、幼鱼和成年 Rio Grande Cutthroat Trout。大约 975,000 条谱系 V 和 VI T。tubifex 于 2010 年至 2012 年间被引入Placer Creek，作为谱系III 蠕虫的可能寡毛纲竞争者。2012 年 4 月，河外池塘被填满，表面重新播种。在 2012 年 7 月至 2016 年 7 月期间测试的 280 多条 Rio Grande Cutthroat Trout 中未检测到大脑分枝杆菌感染的证据，表明寄生虫已从障碍物上游的Placer Creek 盆地。