18 Dec. 2023

For a good part of the year, as night falls, the Gulf of Thailand is adorned with countless green points of light. You can see them from the mainland or during a flight, and even from the International Space Station. But what do these green lights represent? Here's what you need to know.

What Do the Green Lights Above the Gulf of Thailand Correspond To?

Each day as darkness falls, an intense green luminescence sweeps across the Gulf of Thailand. But what's behind it? These light sources aren't the result of any strange phenomenon—they come simply from fishing boats. Fishermen use LED light bars in bright green to catch squid.

This strategy works by drawing them up from the depths. Squid, which feed primarily on fluorescent plankton, naturally rise from deeper waters to pursue their prey and feed. By mimicking the light of plankton, the LED bulbs attract squid to the water's surface, where they're caught in fishing nets. These are then sold locally or exported worldwide, particularly to Europe.

Green Lights Visible from the International Space Station

Visible from shore and from the air, these green lights are equally apparent from space. Indeed, these lights were first documented in the late 1970s when space scientists began mapping Earth at night for the first time. Since then, NASA has published several photographs taken from the International Space Station.

As Michael Carlowicz of NASA's Earth Observatory explains: "Fishing boats can carry more than a hundred of these lamps, generating no less than 300 kilowatts of light per vessel." Add to this the sheer number of fishing boats at sea, and you get an impressive green halo stretching across kilometers of ocean.

The Gulf of Thailand: A Victim of Overfishing

The nighttime images of the Gulf of Thailand are not only striking—they reveal a serious problem: overfishing. For years, intensive fishing operations have decimated numerous fish species. The issue? Fishermen were disregarding restrictions and regulated zones.

In response, the European Union threatened to ban Thai imports in 2015. New regulations followed, requiring all Thai fishing boats to be monitored 24/7 by satellite and allowing suspect vessels to be intercepted at sea or inspected upon arrival at port. Furthermore, customs controls were strengthened. In early 2019, the EU lifted its "yellow card," citing improvements.

Yet today, intensive fishing continues to plague the Gulf of Thailand. You need only observe the increasing number of boats each year from the shores of Koh Samui, Koh Phangan, or Koh Tao, or take an evening flight from one of these islands to Bangkok, to realize that the sea is crisscrossed with endless green light...

Florine Dergelet

Florine Dergelet

A web writer for over 10 years, Florine Dergelet is a traveler driven by the desire to discover the world with an open heart. Each of her articles is an invitation to slow down, to listen, to understand. For her, travel isn't about ticking countries off a map, but about forging bonds—often invisible yet always powerful—with places, peoples, and all manner of creatures from the animal kingdom. Her motto? Advise travelers with integrity, awaken their awareness of animal welfare, cultural respect, and the importance of humble and sustainable tourism. Because the most beautiful memories often bloom far from the spotlight, in the shadow of a trail, in the quiet of a conversation, or in the gentle breath of a world we finally take time to truly hear…