The sea off Thailand's Ko Lan island turned bright green and gave off a strong, grassy smell on Thursday, Oct. 1, as a plankton bloom spread across the water, keeping some swimmers away. A researcher said plankton blooms are a natural, recurring phenomenon caused when nutrients from land wash into the sea and feed rapid plankton growth. -- 🍀 Support NTD 👉 https://donate.ntd.com/ -- 📺 Watch NTD News 24/7 on cable, broadcast, and streaming: https://www.ntd.com/watch 🧶Exclusive Documentaries & Movies on NTD+: https://www.ntdplus.com/utm_source=YouTube&utm_medium=SocialM -- 🔵Sign up for our newsletter to stay informed with NTD News. 👉https://www.ntd.com/newsletter.htm?utm_source=YouTube. If the link is blocked, type in NTD.com manually to sign up. -- © All Rights Reserved.