Army Corps Attacking 'Unique Strain' Of Aquatic Plant In Middletown

MIDDLETOWN, CT — Federal authorities are embarking on a study on how an invasive aquatic plant is attacking a river in Middletown that is a tributary of the larger Connecticut River.

The New England District of the U.S. Army Corps of Engineers, in partnership with the Lower Connecticut River Valley Council of Governments and the Connecticut Agricultural Experiment Station, is conducting a research and demonstration project to better understand the invasive aquatic plant hydrilla that is currently spreading throughout the lower Connecticut River and its tributaries. One of the project study sites is in the lower Mattabesset River located in Middletown.

One of the goals is is to develop safe and effective recommendations that local communities can implement in the near-future to control hydrilla, officials said.

According to the Army Corps of Engineers, Hydrilla was first identified in the Connecticut River near Glastonbury's Keeney Cove in 2016. Also that year, hydrilla was found near the Glastonbury boathouse.

Subsequent surveys done in 2019 and 2020 by the Connecticut Agricultural Experiment Station documented the presence of hydrilla from Agawam in Massachusetts flowing south to Essex in Connecticut. The density of the infestation was estimated on a qualitative scale ranging from "sparse" to "dense," Army Corps officials said.

The invasive plant was then noticed to have spread into many coves, tributaries and boat basins along the river.

Hydrilla spreads through "fragmentation and lateral propagation," according to the Army Corps. Fragmentation occurs when pieces of the plant break off, travel and easily sprout new plants when they come in contact with sediment in a new location. Plant fragments are commonly created and spread when boat propellers come in contact with the plant, causing fragments to break off and float to different areas, at times coming together to form dense floating mats.

In the lower Connecticut River, hydrilla grows very rapidly in the spring through the summer months and persists in the water through the fall, according to the Army Corps.

According to the Army Corps it was determined, through genetic testing, that the hydrilla growing in the Connecticut River is "a unique strain genetically distinct from other strains of hydrilla."

The new strain has been classified as "Hydrilla verticillata subsp. lithuanica."

"Initial examination of Connecticut River specimens revealed morphological features that differed from hydrilla samples previously encountered in the state," Army Corps officials said. "These included a more robust nature, widely spaced whorls often of five-to-10 leaves and a darker color, which prompted concern that the Connecticut River hydrilla might be genetically different from the strains that are currently known to exist in North America."

See more on the Army Corps study and the invasive plant itself here.