OARS Water Chestnut Project

Name:  Suzanne Flint

Organization: OARS

Phone Number: 978-369-3956

Where is the site located?: Assabet River, Hudson through Concord, MA from 42.257690/-71.670746 to 42.466723/-71.356949

Property Overview: Assabet River, from Hudson to Concord, mainly the impounded sections

Management Site Description: River

How many acres are in the management area: ~550 acres

Is it listed on EDDMapS?: No

Habitat Type: River

Initial Invasive Distribution Description: Scattered to heavy, mainly in the shallow, slow-moving sections of the impoundment area of the river. Maps available at CISMA webpage

What this Early Detection Rapid Response (EDRR)?: No

What were the target species? Water Chestnut (Trapa natans)

What was the initial percent cover of invasives?: Varied- see table below

What were the management objectives?: Reduce the populations of water chestnut to levels that can be managed, with relatively low effort, by hand-pulling. Prevent new areas of infestation and prevent the spread from existing areas.

What was the approximate project start date?: 06/01/2016

Project Summary: OARS' Rapid Response Team for 2016 was hired from June-August to hand pull water chestnut along the Assabet River everywhere that i was found (from Hudson to Concord). Volunteers also engaged in hand-pulling on several impoundment sections of the river in 2016.

Control Method: Manual

Disposal Method: Composting off site (away from river edge)

Detailed Project Timeline:

June-Aug: Survey the sections to be managed before pulling
June-Aug: Repeat hand-pulling every summer with hired help and/or volunteers

Funding Sources: 2016 funding came from two Supplemental Environmental Project penalty funds

Final Acres in Management Area: ~550 acres

Percent Cover Invasives:

Water Chestnut Surveys of Managed Assabet River Sections

 

 

 

Hudson Impound.

2013

2014

2016

       Total area surveyed (acres)

13.9

13.9

13.9

       Calculated total coverage (acres)

0.1

1.9

2.0

       Calculated % of total area covered

1%

14%

15%

Crow Island

 

       Total area surveyed (acres)

39.0

39.0

39.0

       Calculated total coverage (acres)

1.6

1.4

2.4

       Calculated % of total area covered

4%

4%

6%

Powdermill Impoundment, Assabet River, Acton

 

       Total area surveyed (acres)

23.4

23.4

23.41

       Calculated total coverage (acres)

4.6

1.5

3.21

       Calculated % of total area covered

20%

7%

14%

Final Invasive Distribution Pattern: See maps. It is possible that as project continues, distribution will change further.

Any comments or takeaways? The population of water chestnut vary in response to summer conditions (rain and temperature), and the seeds have a long (12+ years) viability in the sediments. So, consistent control efforts will have to be applied.

Is your site open to the public?: Yes

Are you able to provide a tour?: Yes