Which agency must grant approval prior to stocking grass carp for vegetation control?

The correct answer is the Department of Fish and Wildlife, as this agency is responsible for managing and regulating fish species and their habitats within the state. Grass carp, being a non-native fish species that can have significant ecological impacts, require careful oversight before they can be stocked into water bodies. This is to ensure that their introduction will not pose threats to native species, disrupt the ecosystem, or cause other unintended consequences. The regulation process involves assessing the potential impacts on local habitats and species, making the Department of Fish and Wildlife the appropriate authority to grant approval for such actions.

Other agencies, while involved in different aspects of environmental management, do not have the same specific mandate or expertise in the management of fish species and aquatic ecosystems as the Department of Fish and Wildlife. For example, the Department of Environmental Quality focuses on pollution control and water quality, the Department of Agriculture deals more with agricultural practices and health, and the Department of Water Resources is concerned with water rights and allocations. Each of these agencies has an important role, but they do not directly oversee the ecological implications of stocking non-native fish species like grass carp.