How does desalination affect the ocean

14 thg 1, But a less chattered-about problem is the effect on the local environment: The primary byproduct of desal is brine, which facilities pump back. Due to their waste water discharges to the sea, desalination plants - and especially MSF plants - must be considered a main source of pollution in the Gulf. It. 28 thg 9, There are a few big challenges. Pulling saltwater into desalination plants can hurt fish and other marine life if it isn't done carefully. Then.