Terrestrial Remediation to Begin Soon
INTRODUCTION
Aquatic Ecosystem Research has been working with the Town of Middlefield’s Lake
Beseck Environment Committee since 2013 to create an applied long-term
management program for the Lake Beseck system. There have been some set backs
in the execution of our holistic management plan; firstly, the repair of Lake Beseck’s
dam required that the majority of the water volume be drained for 300+ days and
thwarted much of our planned activities. During that time, much of the lakebed was
exposed and terrestrial species colonized the area. The majority of the terrestrial
species died when the lake was refilled but the semiaquatic species, namely
Phragmites australis and Typha augustifolia, remained. These species currently inhabit
9-acres in the southern reaches of the lake. This has led to navigational issues, the
inhibition of recreational access, and the displacement of wildlife. We have
established a set of priorities to manage this issue; they are as follows:
1. Mitigate and control plant growth to restore and enhance recreational access.
2. Create a fiscally responsible long-term plan for the management of the
colonizing terrestrial species Phragmites australis and Typha augustifolia.
3. Improve faunal habitats and habitat variability to attract native organisms
including amphibians, reptiles, and birds. Specifically considering bird habitats,
part of the 5-acres to be removed will restore the traditional Canada Goose and
Mute Swan habitat; while leaving the 4-acre southern-most cove colonized to
attract Red-winged Blackbirds and other “reed-nesting” species.
PLAN OF ACTION
Part of Lake Beseck watershed feeds the lake at the southernmost point. This area is
affected by the colonization of terrestrial plants Phragmites australis and Typha
augustifolia over an approximately 9-acre area. Due to the water in-flow from the
surrounding watershed, this area may benefit from the presence of semi-aquatic
plants to act as a riparian buffer, which will prevent excess nutrient accumulation and
sedimentation of the lake’s shallow areas. This will also make future maintenance of
the area more simplistic and fiscally conservative.
To enhance habitat variability and ecological value, we are intending to leave a 4-acre
area at the southernmost bend of Lake Beseck inhabited by Typha augustifolia and
Phragmites australis, which will act as nutrient and sediment sinks for the southern
sub-watershed. To restore property and recreational access along the east and west
sides of the southern portion of the lake, approximately 5-acres of terrestrial plant will
be managed.
TERRESTRIAL SPECIES MANAGEMENT PLAN
We are scheduled to apply the herbicide Imazapyr to control the populations of P.
australis and T. latifolia in the areas that are currently compromising recreational
access and waterfowl habitat. This treatment will occur in the next few weeks and the
herbicide was specifically selected because of its efficacy, cost effectiveness, and
inherent safety regarding human health and environmental impacts. The herbicide will
be applied directly to the plants above the water. Below we provide some data
characterizing the herbicide of choice, Imazapyr:
Imazapyr [2-(4-isopropyl-4-methyl-5-oxo-2-imidazolin-2-yl)-nicotinic acid] is an
enzymatic inhibitor that retards the production of a specific amino acid in plants. The
target amino acid is not present in animals and Imazapyr has been shown to be
effective against both P. australis and T. augustifolia in low doses; furthermore, the
application protocol ensures that effective doses are applied to the standing plant
material in a concentration that is not active in the water column. Imazapyr has a 3 – 8
day half-life in aquatic environments with a pH greater than 5, it does not
bioaccumulate, and has very low toxicity to vertebrates. It is categorized in the lowest
risk categories for human oral or dermal exposure and the concentration necessary to
injure wildlife far exceeds that which will be applied. Finally, there is no evidence of
carcinogenic, genotoxic, or developmental effects from exposure to Imazapyr.
A FINAL NOTE TO OUR CONSTITUENTS
Our goal as a managing entity is to conserve and enhance the beautiful Lake Beseck
system. Over the past few years we have needed to take a triage approach due to the
many challenges that we have faced; however, we are making significant headway in
putting our long term management plan in to action. We have many years of data and
have made some significant decisions about the trajectory of the management plan;
the coming years will be very exciting as we move to implement our long-term
prioritized plan. Finally, your involvement is of the utmost importance and all of the
citizens are an integral part of our holistic plan; please provide any support you can to
this effort.
860.576.8628 mjunewells@aerlimnology.com www.aerlimnology.com