The researchers studied the effects of Sonar A.S. aquatic herbicide on plants in Michigan lakes from 1990 to 1996. They found that the herbicide was effective in controlling Eurasian watermilfoil and curly leaf pondweed while having minimal impact on native plant species. Different plant species responded differently to the herbicide, with some being highly susceptible and others being very tolerant. The impact on plant cover and diversity was dose-dependent, with higher doses leading to declines that usually recovered within 1 to 3 years. Overall, low-dose applications of Sonar A.S. were effective in managing invasive plants without harming native species.