Our conservation team is busy getting ready for another aquatic weed season in our waterways! Phragmites australis var. australis and Ludwigia (Ludwigia hexapetela and Ludwigia peploides) are the main targets as they have been found occasionally in the Multnomah Channel.
Staff will also be keeping an eye out for other priority aquatic weeds that haven’t yet been found in our waterbodies. In addition, we are surveying purple loosestrife (Lythrum salicaria) for presence of biocontrol agents — insects that exclusively feed on a specific weed to help keep the weed from becoming too pervasive.
Summer and fall are the best times for spotting aquatic weeds since they are in bloom during this time and follow-up control measures are most effective. The District has already completed a summer survey of Sturgeon Lake, the largest lake on the largest river island in the country.
Later this summer we will be out on Multnomah Channel, in Linnton and around Sauvie Island surveying for priority aquatic weeds using our new 16’ jon boat. We are also working with the Scappoose Bay Watershed Council to survey Scappoose Bay by kayak. These boats were purchased with funds from an Oregon Department of Agriculture Priority Noxious Weed Grant. Thanks to this grant we are able to access miles of waterways in our District that we otherwise wouldn’t be able to get to from land!