Which agency was designated as Florida's lead agency in aquatic plant control in 1970?

The Florida Department of Natural Resources was designated as the state's lead agency in aquatic plant control in 1970 due to its focus on managing Florida's natural resources, which includes the control and management of aquatic vegetation affecting water bodies. This agency was responsible for coordinating efforts to address the challenges posed by invasive aquatic plants, which can disrupt ecosystems, affect water quality, and hinder recreational activities.

By being assigned this role, the department was able to develop strategies and implement programs aimed at managing and controlling invasive plant species, working towards the preservation of Florida's diverse aquatic environments. This historical decision laid the groundwork for future advancements in aquatic management and set a precedent for ongoing collaboration between various stakeholders in the state.

The other agencies mentioned in the choices have different roles and responsibilities that do not specifically align with being the lead agency in aquatic plant control during that time.