Wipe out invasive aquatic plants (like hydrilla!) using Grass Carp

from wikipedia:

The grass carp grows very rapidly, and young fish stocked in the spring at 20 centimetres (7.9 in) will reach over 45 centimetres (18 in) by fall, and adults often attain nearly 1.2 metres (3.9 ft) in length and over 18 kilograms (40 lb) in weight. According to one study, they live an average of 5-9 years with the oldest gaining 11 years.  They eat up to 3 times their own body weight daily. They thrive in small lakes and backwaters that provide an abundant supply of fresh water vegetation.

This approach is less novel than you might think and is being employed in many American cities affected by hydrilla.  What is hydrilla?

from wikipedia:

Hydrilla is naturalised and invasive in the United States following release in the 1960s from aquariums into waterways in Florida. It is now established in the southeast from Connecticut to Texas, and also in California.^[8] By the 1990s control and management were costing millions of dollars each year.

Who throws a few fish into a lake to solve a prolific invasive plant?  Virginia, North Carolina, South Carolina, Texas and Florida to name a few.  An added point of interest regarding the Grass Carp, their intelligence... and their ability to foil anglers.

from ufl.edu:

However, lake managers and biologists were also in for a few surprises: when attempts were made to remove the fish from the lake, they were amazed at the the carp's uncanny ability to outsmart virtually every type of fishing technique. Nets, hook-and-line, electro-shocking, even poison baits were minimally successful, especially after the first application. It soon became apparent that once released, grass carp were nearly impossible to remove. As of 2005, there are still no easy ways to remove grass carp from a stocked lake.