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New Zealand mud snail
Invasive Species Pose Management Challenges

Earlier this month, the U.S. Forest Service released its first ever national-level policy on management of invasive species throughout aquatic and terrestrial areas of the National Forest System. For centuries non-native species have been introduced to different regions for many varied purposes, such as food, clothing, medicine and recreation, and the development of the United States has been no exception. We are just now beginning to understand the potential negative implications of these introductions. Today, approximately $137 billion in damages are caused every year by roughly 50,000 non-native species in the United States alone (Pimentel et al. 2000). A variety of methods are used in managing their populations, such as chemical control, habitat restoration, depredation permits, and bounties for individuals that contribute to eradication.


Since most of our work at FISHBIO is related to fish we tend to focus on the 'nuisance' non-native species that exist in aquatic or riparian environments, such as New Zealand mud snails and water hyacinth. However, not all non-native species are classified as being a threat and many are things that we enjoy in our everyday lives, including the dog in our back yard and the vegetables in our refrigerator. It is important to identify which of the nonindigenous species are harmful to existing populations and find ways to mitigate their effects. This can be a challenge, especially considering we have yet to develop consistent terminology to define the types of non-native species (Colautti and MacIsaac 2004) we refer to during discussions, debates and reporting. What some may describe as "invasive", others may define as "non-native", "alien" or "nuisance" species. The recent Forest Service policy defines invasive as, "an alien species whose introduction does or is likely to cause economic or environmental harm or harm to human health."


Whether introduced by accident or deliberately, non-native invasive species are posing a threat to the biodiversity of indigenous populations, and 48% of the species listed under the Endangered Species Act are cited as being threatened by non-native species (Sanderson et al. 2009). As an outdoors enthusiast or a fisheries biologist, simply choosing the right kind of fishing gear and disinfecting equipment after use are ways that you can help prevent the spread of invasive species.

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Group Effort
Armed with a half-dozen backpack electrofishers, a crew of "netters" and "shockers" waded through the Lower Kings River Fish Hooklast week in search of rainbow trout. FISHBIO assisted with multi-pass depletion electrofishing efforts as part of the Kings River Conservation District's (KRCD) annual rainbow trout population study in the Kings River below Pine Flat Dam in California's Central Valley.... Read more >
IN THE NEWS: Recent stories you might have missed...
Salmon flood hatcheries, great 2012 predicted
San Francisco Chronicle

Trips to Nimbus Hatchery last week on the American River near Sacramento and to the Coleman National Fish Hatchery on Battle Creek near the Sacramento River unveiled great news for salmon, the people who fish for them, and those who love to eat them. At Nimbus, adults and youngsters alike watched the salmon swim up the American River, jump up the fish ladders to the hatchery, and occasionally make spectacular jumps in the river. It's the best show in years... Read more > 

Sacramento River fluctuations put salmon eggs at risk during run

Red Bluff Daily News 

Chinook Salmon may be the king but, in a ecosystem in which water is limited, its eggs may be left high and dry. Thousands of late fall salmon eggs in the Sacramento River that have yet to hatch are at risk of being dried up as the river fluctuates. While many factors can influence the flow of the river, the most recent river changes can be attributed to operations at Keswick and Shasta dams. At the start of the spawning season in October, river flows were around 7,000 cfs.... Read more > 

State fights U.S. mandate to remove levees' trees

San Francisco Chronicle  

Seen from above, the Sacramento-San Joaquin River Delta reveals a tidy patchwork of farmlands transected by river channels and canals, many lined by trees and brush. From the ground, the view is of waterfowl feeding, with hawks soaring overhead. Salmon and steelhead hover near the tree-shaded banks where the water is cooler and insects plentiful. Revamped federal rules, however, threaten this riparian habitat and flood management efforts in the delta and along the San Francisco Bay's creeks.... Read more > 

Napa River restoration project serves as model

San Francisco Chronicle 

The U.S. Environmental Protection Agency's top man in the region shook his head after tromping through a restored Napa River floodplain and then motoring on a boat through one of the nation's premier riparian revitalization projects. "Why," asked Jared Blumenfeld, the EPA's regional administrator, "do we not hear more about this?" The grapevine is getting louder, with community planners and environmentalists taking note, as Napa County moves forward with a project that, when completed, will have restored 15 miles of the Napa River... Read more > 

 Dam near Dos Palos is key to restoring salmon run

Fresno Bee   

The fish-friendly makeover of the San Joaquin River is expected to start with a $35 million renovation at Sack Dam near Dos Palos in 2013. That will be too late to meet a 2012 deadline for reviving chinook salmon runs in the river. It will be years before other similar projects will turn the river into a thoroughfare for salmon, as it was six decades ago. But even without fixing the dam, federal officials may still return long-dead salmon runs to the river next year. They could just capture and haul the fish around dams... Read more >