The once-polluted Bronx River has been showing signs of improvement lately, and now $2.5 million will be going to local organizations to clean up the water. Scientist Paul Mankiewicz, of the Gaia Institute, has received $200,000 to plant millions of mussels along the shoreline of the Bronx River that will filter out the water and make it cleaner.Rocking the Boat, an organization dedicated to teaching children how to build boats, will receive $57,000 to build a drainage system that would naturally filter rainwater before it reaches the Bronx River. The cleanup projects are being funded from fines given to people and companies that are caught dumping in the river.