Invasive aquatic weeds hinder access to marina docks and slips in the Sacramento / San Joaquin Delta, resulting in costs for management and potential lost business for marina operators.
Water hyacinth collects around slips and docks and other structures in the water. If not removed or treated, the weeds continue to grow. By late summer, water hyacinth and other weeds can block marina entrances, damage boat propellers, or even shut down marinas.
Because marina operators cannot spray herbicides to manage invasive weeds, they must rely almost exclusively on manual labor to remove invasive weeds. How this is done depends on the marina and the size of the infestation.
For small infestations the marinas will have a person go out, remove the weeds from the water and throw them out. In late summer and fall, when water hyacinth infestations are typically at their worst, this may be done daily.
For larger infestations the marinas will gather up the weeds and push them out into the middle of the river. Under a permit from the Army Corps of Engineers, booms can be used to 'fence out' floating weeds, though booms cannot be used in any area where they restrict traffic.
The costs to manage invasive weeds can add up. The table below shows the annual estimated expenditures by marinas for 2014 and 2015 to manage invasive weeds.
