Why are Aquatic Non-native Invasive Species a Concern? 

Aquatic non-native invasive species (NIS) include plants, animals, and diseases they carry, that are introduced to areas beyond their natural range. Non-native aquatic organisms can be found in coastal and inland waters worldwide. Though some non-native species introductions may have minimal effects on their new habitat, many invasive species can have enormous negative impacts on our economy and environment. Nearly 250 non-native invasive species occupy the San Francisco Bay-Delta, and four new species establish here every year.

Non-native organisms affect the environment in many different ways. Some consume or compete with natives species, potentially contributing to their extinction. Others may overgrow or degrade habitats, or decrease fisheries stocks. Other NIS affect human activities by clogging waterways, swimming areas, and flood channels, or by fouling boats, docks, and pipes. Non-native species can also carry parasites and diseases that may prove disastrous to both native species and human health.

Non-native invasive species cost the U.S. billions of dollars annually. Control efforts can slow the spread of invasive species, thereby maintaining native habitats; however, complete eradication of established aquatic invasions is expensive and nearly impossible. The most effective strategy for managing NIS is to prevent introductions. This is a priority for resource managers, but everyone needs to help prevent introductions in the Bay-Delta.

Check out our "Preventing Introductions" page for ways you can help!


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*RIDNIS Project Concern Page, September 2003 - September 2005
(*Reducing the Introduction and Distribution of Aquatic Non-Native Invasive Species through Outreach & Education)
University of California Cooperative Extension, Department of Environmental Science and Policy
This project is funded by the CBDA California Bay-Delta Authority in cooperation with the University of California Cooperative Extension.