What is the purpose of the River and Harbor Act of 1899?

The River and Harbor Act of 1899 primarily aimed to protect navigable waters from pollution, particularly from the dumping of refuse and other harmful substances. One key aspect of this act was its focus on maintaining navigable waterways, which indirectly relates to the management of invasive species that can disrupt these ecosystems and impact navigation.

Although the act does not explicitly mandate the removal of invasive plant species, it emphasizes the importance of protecting the waterways to ensure their usability for commerce and transport. Invasive species often threaten this balance by outcompeting native flora and disrupt ecological and navigational functions. Therefore, this answer aligns with the broader goals of the act regarding the preservation and integrity of navigable waters.

The other choices do not accurately reflect the main purpose of the River and Harbor Act. Regulating fishing practices and controlling water quality, while important, were not the primary objectives of this legislation. Similarly, authorizing vessel construction pertains more to maritime commerce than to the core initiatives of the act, which focused on maintaining navigability and preventing pollution in waterways.