Quagga Mussels at Lake Pleasant
The introduction of non-indigenous, aquatic invasive species into the lower Colorado River and the inland waters of Arizona pose serious biological, environmental, and economic threats in Arizona. Aquatic invasive species (AIS) are invasive plants (e.g., giant salvinia; hydrilla; water hyacinth) and animals (e.g., quagga mussel; Asian carp; red claw crayfish) that are transported and released, intentionally or unintentionally, outside of their native or historical range. Because they have few natural controls in new habitats, AIS spread rapidly and often alter the newly invaded aquatic system permanently. Once established, many invasive species prove exceptionally difficult to manage or eradicate.
The main pathways for introduction of AIS into Arizona include various human introductory means, such state interconnected waterways (e.g., Colorado river reservoirs), inter and intrastate movement of watercraft, and the discard of live aquatic wildlife and plants (e.g., pets, food fish, decorative aquatic plants) into local waters, just to name a few. AIS can completely alter aquatic ecosystems and threaten the integrity of water resources and infrastructure. Consequences of AIS presence in Arizona include the destruction of native plant and animal habitat, damaged recreational sites and opportunities, lowered property values, clogged waterways, negative impacts on irrigation and power generation, and decreased overall biodiversity.
Close to Phoenix, Lake Pleasant was invaded by an AIS, the Quagga Mussel (native to the Black and Caspian Seas) sometime around 2005. Since then, boats and anything else that is in the waters of Lake Pleasant with have either the young mussels (called veligers) for short exposure or adults for exposure over 4-5 days, attached or living in wet places. All it takes to move these mussels to another water is to pull your boat out of a contaminated water (like Lake Pleasant) and put it in another lake without pulling the drain plug and allowing your boat to completely and fully dry out. For medium to large boats, drying out completely can take 30 days or more. If you have a large boat that has been moored or in a slip for weeks or months, adult mussels and young will be everywhere it’s wet in your boat (in the motor, ballast tanks, etc.). You must decontaminate your boat with a very specific cleaning protocol. To avoid further spread of these invasive mussels or other AIS, it is critical for anyone who owns or uses watercraft, or has a business reliant on watercraft, to understand the essential nature of aquatic invasive species containment led by the Arizona Game and Fish Department. The spread of Quagga Mussels and other aquatic invasive species has far-reaching impacts, both financial and ecological, that can touch virtually every resident of the state. To learn more about Aquatic Invasive Species click here: www.azgfd.gov/ais.