Larval trapping is conducted in the spring and is used to detect the presence or absence of egressing larval northern pike and/or other species originating in tributaries. As funding allows, larval trapping occurs in streams prior to and after fish passage impediment removal or remediation projects and/or habitat restoration projects led by the Planning and Parks Department.
The Program has captured dozens of other fish species, including four least darters captured in Mee-Kwon Creek in 2013. The least darter is a species of special concern in Wisconsin and only has been captured in Ozaukee County on one other occasion since 1924. The Department maintains a fisheries database containing years of larval trapping data from over 18 tributary streams. This data is sent to the WDNR for inclusion in the statewide Surface Water Integrated Monitoring System (SWIMS) database.