Clog lakes & waterways Interferes with commerce and recreation Displace native plants Clogs water diversions and pumps Depletes dissolved oxygen levels Increase sedimentation Can cause flooding
Many seeds & small seedlings move easily. Spongeplant mixed with duckweed. Red circles show spongeplant seedlings. Seeds survive at least three years.
It chokes out everything. 2003 first California infestation found in Redding and Arcata. Out competes several other aggressive water weeds, like water primrose and parrots feather
2003: First records were in Arcata and Redding. 2007: San Joaquin River in Fresno. Antioch in Sacramento River, but seemed to disappear after a storm. 2008: Found in a canal off the Kings River east of Fresno and canals in western Fresno County & 2010, it was again found in the Delta.
To report plants or find out about surveys: Patrick Akers at Left: Spongeplant in a canal in western Fresno County. Right: The same canal two weeks after treatment. Spongeplant spreads easily but it is relatively easy to control, if it hasn’t had time to make a lot of seeds. But maybe we can beat it. HELP THE EFFORT! The California Department of Food and Agriculture will be surveying in 2011 to find out how much spongeplant has spread. You can help by reporting finds or having your stream, pond, or canals checked. And thanks. For more information: Before treatmentAfter treatment
Asian Clam Chinese Mitten Crab New Zealand Mudsnail Florida Watersnake (Nerodia) Asian Carp
Introduced in 1800’s for human consumption High densities, out-competes native clams Impairs water delivery systems by clogging pipes, valves and sprinklers Traps sediment, forms bars in agriculture canals, alters flow Bioaccumulation of toxins
Intentional releases for human consumption and/or via ballast water Clog fish salvage facilities Create losses for fisheries Reduced catch Damages fishing nets Threatens levee stability Potential host for human lung fluke
From New Zealand 750,000 NZMS per square meter Competes for space and food Ties up nutrients – not digestible by most fish or birds, shell takes a long time to decompose Shells block pipes, filters and grates Ken Davis Distribution of the New Zealand mudsnail in California.
Native to southeastern US Threat to CA native and federally listed giant garter snake ( Thamnophis gigas )
Reach extremely high population densities Impact populations of native mussels and snails (black carp) Potentially deplete zooplankton populations (silver and bighead)
Decontamination Hazard Analysis and Critical Control Point Planning
Tool that manages the risk of moving non-targets Risk assessment of potential pathways
Risk assessment determines the likelihood of moving species to an area where they may become invasive. This process assumes that the impact of any invasive species introduction is significant
Once it is determined that a pathway poses a significant risk, then a plan is implemented to reduce this risk. Utilize the HACCP planning process framework.
Easy five step tool Defines the critical point in a given activity whereby the risk of a hazard can be reduced to an acceptable level. The risk of a hazard is reduced by means of a control measure. This control measure is then evaluated