The Sepang Besar River needs clean waters to nurture mangroves and wildlife such as this little heron. Once badly polluted, the Sepang Besar River is recovering. It’s greenish-blue brackish water today supports a thriving mangrove forest. Yet, 20 years ago, it was as good as dead.

http://www.star2.com/living/living-environment/2015/06/15/once-dead-sepang-besar-river-comes-back-to-life/