Grand Canyon Fish Bounce Back!

Native fish populations in the Grand Canyon's Bright Angel Creek have experienced a remarkable recovery, increasing by over 400% following extensive efforts to suppress invasive trout species. Historically, Bright Angel Creek supported at least five of the Grand Canyon's native fish, including the endangered humpback chub, which was first scientifically described from specimens collected in this vicinity.

Non-native brown and rainbow trout, introduced in the early to mid-20th century, predated current environmental awareness and ecological knowledge. These invasive species preyed on native fish, leading to significant population declines. To combat this, a multi-year project, initiated in 2006 and funded by the Bureau of Reclamation and National Park Service, targeted the reduction of these non-native trout.

Conservationists employed two primary methods for non-native trout removal: a weir to capture larger spawning trout entering from the Colorado River, and electro-fishing to assess populations and remove trout within the creek. These methods were implemented during the fall and winter seasons across several years, including 2002-2003, 2006-2007, 2010-2011, and 2011-2012. Notably, the weir captured large trout, while electro-fishing allowed for broader population assessment and removal.

Alongside suppression efforts, humpback chub have been translocated to safer habitats within the Colorado River system, enhancing their survival prospects by reducing threats from predators. The successful reduction of invasive trout has led to the observed increase in native fish, with young flannelmouth suckers noted rearing in the creek for the first time in decades. This restoration aligns with National Park Service policies requiring the preservation of native species and ecosystems.