Trapa natans scorecard

2205
Species:  Trapa natans
Contributor(s):
Impact
SpreadNotesScore
Spread Rate Spreads: by the rosette and fruits detaching from the stem and floating to another area on currents or by fruits clinging to objects, birds and other animals. If unmanaged, populations can increase dramatically. 5
Spread Amount Has the ability to survive in colder climates. Currently invades the eastern US as far south as Virginia. 3
DamageNotesScore
Ecological Trapa natans grows best in waters that are nutrient rich and moderately alkaline. It can grow in water up to 5 m deep, but prefers shallow waters (0.3 to 2.0 m deep). 4
Agricultural 0
Infrastructure Water chestnut infestations limit boating, fishing, swimming and other recreational activities. 3
Cultural When the plant occupies a site, most recreational activities such as swimming, fishing from the shoreline, and the use of small boats are eliminated or severely impeded. 4
Health 0
BenefitNotesScore
Ecological 0
Agricultural Was introduced as a garden pond ornamental, but this is likely not important today. 0
Infrastructure 0
Cultural 0
Benefit Health 0
Ability to Respond
Ease of ResponseNotesScore
Detection Fairly easy to detect because of the distinct look on the floating leaves. 1
Control Specialized methods of control are required to handle water chestnut infestations. Eradication is difficult because water chestnut seeds may lay dormant for up to 12 years. 4
Tools in PlaceNotesScore
Entry Nothing in place. In Michigan, knowingly possessing or introducing the plant can be considered a felony, fine up to $1,000,000. 0
Control No mandates. 0
Outreach No outreach. 0
Scorecard Totals
Impact Total:
19
[Impact] = ([Spread] + [Damage] - [Benefit])
Ability to Respond Total:
5
[Ability to Respond] = ([Ease of Response] + [Tools in Place])
Confidence
Confidence:  medium
Notes:
Sources: