Free Flash Slideshow by cu3ox.com v1.1

Exploring the beautiful nature of California


California Nature:  Endangered Fish


California is a large state, the 3rd largest in the U.S.A., and depending on where you go, can range broadly in habitat type and, also, climate. For this reason, California plays host to a huge variety of fish.

Fishes are aquatic vertebrates that have fins, gills and scales. Gills are the part of the respiratory system that provide surface area for exchanging oxygen and carbon dioxide under water. Fish are ectotherms, commonly referred to as 'cold-blooded', meaning their temperature is regulated by the temperature of their environment. They have a range of diets, being herbivores, carnivores, or omnivores. Some fish reproduce by laying eggs, while others reproduce by bearing live young.

California fish species reside in freshwater and coastal/marine waters. Freshwater fish are fishes that live at least part, if not all, of their lives in bodies of fresh water with a salinity of less than .05%. Forty-one percent of all known fish species are found in freshwater.
many California king salmon are disappearing quickly There are currently 34 species and subspecies of fishes listed as either threatened or endangered by the State of California or the federal government.

Since 2002, scientists have documented catastrophic declines of delta smelt, longfin smelt, threadfin shad, Sacramento splittail, and striped bass. The state's largest salmon run of Central Valley fall-run chinook is suffering from record decline.

Federal fisheries managers have cancelled commercial and recreational salmon fishing in California the past two years due to low salmon returns. White and green sturgeon numbers in San Francisco Bay and the Sacramento River have also fallen to alarmingly low levels, and the southern green sturgeon population was federally listed as threatened in 2006.

The San Francisco Bay-Delta ecosystem, an ecologically important estuary and a major hub for California’s water system, is now rapidly unraveling. Once-abundant fish species are in critical condition due to record-high water diversions, pollutants, and harmful nonnative species that thrive in degraded Delta habitat. Federal and state agencies have allowed record levels of water diversions from the Delta in recent years, leaving insufficient fresh water to sustain native fish and the Delta ecosystem.

Suddenly the Chinook salmon that swim upstream to spawn in the fall, the most robust run in the Sacramento River, have disappeared. The almost complete collapse of the richest and most dependable source of Chinook salmon south of Alaska left gloomy fisheries experts struggling for reliable explanations, and coming up dry.
many trout are becoming endangered in California nature The Bonytail Chub is on the U.S. Endangered Species List, classified as endangered throughout its range in Arizona, California, Colorado, Nevada, and Utah. This fish lives in large, fast-flowing waterways of the Colorado River system, and the large-scale damming of the river has diminished available habitat. Other threats to the Bonytail Chub have been the introduction of non-native fish that compete for food and habitat, and may prey on it or hybridize with it.

Few places can boast as many types of rainbow, golden, redband, or cutthroat trout as the Golden State. Unfortunately, during the past 150 years, human activities have altered and damaged the health of the habitat that supports these trout and taken their toll on our natural heritage. Many of California's native trout are not as widespread as they once were. Our native trout streams and populations have undergone a great deal of change due to the tremendous growth of the Golden State.
Most of California's steelhead populations, and some inland native trout are now listed under the Federal Endangered Species Act. Several other native trout are being evaluated for listing. The bull trout which was once found in the upper McCloud River, is now extinct in California. Another specie, the well-known coastal rainbow trout is still present in much of its original range, but many wild runs of steelhead, the sea-running form of rainbow trout, are at risk of extinction.

Because of its one-year life cycle and relatively low fecundity, Delta smelt is very susceptible to changes in the environmental conditions of its native habitat. A large number of these changes have led to a fluctuating population decline, as measured since 1959. Efforts to protect the endangered fish from further decline have focused on limiting or modifying the large-scale pumping activities of state and federal water projects at the southern end of the estuary.
 
 
Website Created by Website Creations

About us      Privacy Disclaimer      Advertisers     Contact Us     Bookstore    Sitemap     Search    Floridian Nature