Invasive Algae Spreading

Starry Stonewort, an invasive macro algal species has bloomed in Lake Memphremagog Vermont causing the closure of the area. Review article here.

Starry Stonewort is a macro alga that can be confused with aquatic plants and its native relatives chara and nitella. The main distinction is the white star shaped oocytes that are one form of its reproductive strategies.

This macro algae can form thick stands and floating mats that can push out native species and hinder recreation and property values. Starry Stonewort can grow to depths of 29 feet causing impacts to the native Nitella populations. Nitella filter nutrients from the water column and keep phytoplankton populations in check, as well as provide habitat during the winter months for macroinvert species and fish species.

Starry Stonewort can grow to seven feet long and can spread via fragmentation and the star shaped oocytes. Studies have shown a direct impact on local fish populations through the reduction in spawning and nursery habitat. In bodies of water throughout the Northeast, this invasive alga has caused a challenge for lake management professionals and users.

Starry Stonewort like Nitella can limit phytoplankton populations within the body of water, however Stonewort will drastically shift the population dynamics of the phytoplankton community to one favoring littoral algae only. This can have a substantial impact on the benthic invertebrates within the body of water and thus the fish populations.

Studies have indicated that in bodies of water with Zebra mussels, there will be a beneficial relationship for the Starry Stonewort similar to that of Cladophora. In essence the Zebra mussels provide habitat and food for the Starry Stonewort to proliferate.

Lake Memphremagog is the first confirmed body of water to have Starry Stonewort within Vermont. It was first discovered there in 2015. In nearby NY, many bodies of water outside of the Adirondacks have confirmed populations of Starry Stonewort. As of summer 2015, no bodies of water within the Adirondack State Park have confirmed populations. This could change as this form of alga is very easily spread through fragments and the star shaped oocytes.