|Volunteers paddle among|
nuisance pond plants
The Wood-Pawcatuck Watershed Association (WPWA) – in conjunction with URI Watershed Watch, RI Natural History Survey, and RIDEM – hosted a two-part invasive species workshop this past week. The first part of the workshop was held at the Coastal Institute at URI’s Kingston Campus on Thursday, July 14th from 6:00 to 8:30 PM. This portion of the workshop focused on educating volunteers about aquatic plant ecology, training them to identify the invasive plants, and discussing with them all that a survey entails. The second part of the workshop took place on Saturday, July 16th from 9:00AM to 12:00 noon at the Kingston Community Center at Asa Pond in South Kingston.
|A view finder allows you to look|
under the surface of the water
It was here that the volunteers reviewed and put into practice the identification skills they developed in part one of the workshop. The volunteers learned how to conduct the survey from boats, canoes, and kayaks. Anyone with access to a boat was welcome to join in the free survey. Plant identification guides and other necessary materials were provided free of charge. One such material involved in the survey were viewfinders, which are essentially see-through cylinders that allowed participants to view the submerged aquatic vegetation without any glare from the sun. Secchi disks were used to test the turbidity of the water. Volunteers gathered samples from the pond and placed them in bags labeled with their location and then marked that location on a map of the pond.
|Native floating heart (white flowers)|
Invasive species can have a significant impact on the ecosystems they invade and Asa Pond is no exception. While plants are generally considered beneficial to aquatic ecosystems, as they lower the water temperature through shading and prevent erosion, invasive plants can disrupt the natural ecosystem when they out-compete native species. According to Elizabeth Herron, who has worked for the URI Watershed Watch since 1992, the most common submerged invasives in the Rhode Island are – in decreasing order of abundance – variable leaf milfoil and fanwort. These species are particularly prolific because they can reproduce from fragments; in other words, a piece of one of these plants can grown into its own full-grown plant. Also, as may be the case with purple loosestrife overtaking native loosestrife and nymphoides peltata out-competing native floating heart, the bright colors of the invasives are more attractive to pollinators, which leads to more seeds being spread of the invasives and, thus, their proliferation.
|Invasive yellow floating heart|
Herbicides are the most effective means of combating the overabundance of invasive species and some have even been developed to specifically target invasives while leaving native plants unscathed. Unfortunately, herbicides can be very expensive and require a permit from the Department of Environmental Management; thus, they are not always a viable option for control of non-native species. Preventing the introduction of invasive species is generally the most desirable option; however, many people introduce invasives unknowingly and, education and outreach are important. Oftentimes, boats will introduce invasives when they are not properly washed. Similarly, plant fragments that remain in trail/bait buckets can lead to the introduction of invasives to areas where they’ve not previously been seen. Protocol for cleaning boats and buckets is currently being established. WPWA is currently working with groups in Connecticut to get support for invasive aquatic plant monitoring.
|Variable Milfoil is an invasive species|
The good news is that despite the heavy public use of Asa Pond, no invasive aquatic plants were detected during the survey. Still, throughout Rhode Island there is much work to be done in terms of preventing the spread of aquatic invasive plants, but through educational public outreach events such as the two-part workshop, progress can be made. If improvements are to be made it will require hard work on the part of volunteers and stakeholders throughout the watershed. If the turnout for this year’s workshop is any indication, there are many citizens concerned with the health of their watershed.
|Invasive water chestnut|