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Geology topics

M.B. Nielsen

Publications and source records attributed to M.B. Nielsen.

3 recordsLinked to original sources
USGS2005

Blue tilapia (Oreochromis aureus) predation on fishes in the Muddy River system, Clark County, Nevada

Blue tilapia (Oreochromis aureus), native to North Africa and the Middle East (Courtenay and Robins 1973, Fuller et al. 1999), has been introduced around the world as a human food source, for vegetation control, and as a game fish (Costa-Pierce and Riedel 2000). Blue tilapia has been particularly successful in establishing and spreading in North American waters where it has been reported to change fish community structure and cause native fish decline (Courtenay and Robins 1973, Fuller et al. 1999). Because of these detrimental effects, it is now generally considered an unwelcome introduction into North American waters (Dill and Cordone 1997, Fuller et al. 1999).

Western North American Naturalist↗
USGS1998

The status of Moapa coriacea and Gila seminuda and status information on other fishes of the Muddy River, Clark County, Nevada

Moapa coriacea is endemic to the headwaters (Warm Springs area) of the Muddy River, Clark County, Nevada. The Warm Springs area was snorkeled and Moapa coriacea and Gila seminuda enumerated in August 1994 after a fire, and in May 1997 after a diversion dam had been removed from the downstream end. Gila seminuda had been reported in greatest abundance downstream from the Warm Springs area and we estimated the population there through mark and recapture from January to March 1995. There was a dramatic reduction in native fishes in the Warm Springs area between 1994 and 1997, coinciding with the invasion of Oreochromis aurea. Downstream from the Warm Springs area Gila seminuda was the most frequently netted species while O. aurea was relatively scarce. The fish population (native and non-native) decreased in a downstream direction; the causative factor(s) have not been identified.

Nevada↗