Ameiurus nebulosus

Mandrak (2009) reported that the main mechanism for A. nebulosus is competition: monopoly of resources, interaction with other invasive species and predation.

Among the affected species by predation indicated by Mandrak (2009) are Oregon spotted frog Rana pretiosa in California, Oregon and Washington and Shasta crayfish Pacifastacus fortis in California.

Mandrak (2009) reported that the main mechanism for A. nebulosus is competition: monopoly of resources, interaction with other invasive species and predation. The main outcomes are altered trophic level, damaged ecosystem services, ecosystem change/habitat alteration, and modification of natural benthic communities, negative impacts on aquaculture/fisheries, reduced native, biodiversity, threat to/loss of endangered native species.

The genus Gasterosteus in British Columbia is affected by competition with and predation by A. nebulosus, which extirpated the Gasterosteus species pair, the only native fish in the lake (Hatfield, 2001).

Nonnative predators, including Brown Bullhead, have been shown to reduce the abundance and diversity of native prey species in several Pacific Northwest rivers (Hughes and Herlihy 2012).

The genus Gasterosteus in British Columbia is affected by competition with and predation by A. nebulosus, which extirpated the Gasterosteus species pair, the only native fish in the lake (Hatfield, 2001).

\"The impacts of alien invasive species can be particularly acute on endemic species with a limited range. In the Pacific Islands Ecological Area, four endemic stickleback species pairs (Gasterosteus spp.) that live only in individual small lakes have been listed by COSEWIC. The species pair in Hadley Lake became extinct in the early 1990s shortly after the unauthorized introduction of brown bullhead (Hatfield 2001). The presumed mechanism for the extinction was predation on stickleback eggs by the introduced brown bullheads.\"; \"This Canadian endemic fish was known only from Hadley Lake, Lasqueti Island, British Columbia. It was lost as a result of nest predation by the introduced brown bullhead.\"; \"This species formerly inhabited Hadley Lake on Lasqueti Island, British Columbia, in the Strait of Georgia. It was a unique BC endemic restricted to this single lake. It was first discovered in the late 1980s, but became extinct following an unauthorized introduction of catfish (Ameirus nebulosus) to the lake.\"; \"Prior to the introduction of catfish to the lake, the primary limiting factor for this species was the capacity of the lake to produce benthos. There were no other fish-eating fish species, and predation from birds (herons, kingfishers and loons) was likely minimal. The extinction of the Hadley Lake pair might have been prevented, had anglers and other citizens been educated about the potential swift and irreversible catastrophic consequences of introductions.\"