What can you do? - A Short Story of Terror and Change — Scott Anderson

An aggressive alien race known as the Colar have deposited thousands of carnivorous creatures to spread terror and disruption throughout the world.
Aggressive and hungry, the human civilization has been damaged in a way that would allow the Colar the ability to land, strip-mine the planet for forty years, and then leave. The humans would then be abandoned in place.
Following the deposit of the carnivorous beasts, a group from the Moara homeworld land on the blue-water planet to feed their own animals. Clearing parts of the planet, the owner of a successful trading house discovers that the human world should be protected by a distant race that is unaware of the recent invasion.
Ambitions follow needs, and the people of Earth are caught between the desires of others.