This image combines two rare natural phenomena: the starry night sky above Puerto Rico and the bioluminescent glow of plankton in Laguna Grande Bio Bay. It is the only image in this post that qualifies as true bioluminescent astrophotography.
The stars of Cassiopeia and the Andromeda Galaxy (M31) are visible above the bay, while the bright blue streak in the water was created by bioluminescent plankton disturbed by a passing boat. The glowing trail marks the boat’s engine and wake, leaving a luminous signature across the dark water.
Bioluminescence is a natural light-producing process found in certain living organisms. In tropical bio bays like Laguna Grande, the glow is produced by microscopic plankton called dinoflagellates, which emit blue light when disturbed. This light results from a chemical reaction within the organism and serves as a response to motion, causing waves, wakes, and moving objects to briefly glow in the darkness.
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| Bioluminescent astrophotography — Cassiopeia and Andromeda over Laguna Grande Bio Bay, Puerto Rico. |
This final image is a two-exposure composite, created to accurately represent both the night sky and the bioluminescent water — something that is extremely difficult to capture in a single frame.
The first exposure was taken from a moving boat to record the intense bioluminescent glow created by the engine and wake. The second exposure was captured from the shore, allowing for a longer exposure to properly record the stars and galaxies overhead. Both images were later combined in Adobe Photoshop.
Capture Details
Exposure 1 (Bioluminescence – boat):
Canon EOS 60Da • EF 16–35mm f/2.8L II USM
1.3 sec • f/2.8 • ISO 6400 • Flash fired
Exposure 2 (Night sky – shore):
Canon EOS 60Da • EF 16–35mm f/2.8L II USM
4 sec • f/2.8 • ISO 12800
The use of flash — unusual in astrophotography — proved essential for capturing the peak intensity of the bioluminescent water without washing out the surrounding environment.
The following images were captured directly from the boat and show bioluminescence as night photography. They include visible parts of the vessel and were taken from different angles and distances, illustrating how the glow changes with motion and perspective.
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| Bioluminescence - Bio Bay Laguna Grande |
Canon EOS 60Da • EF 16–35mm f/2.8L II USM • 4 sec • ISO 12800 • f/2.8
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| Bioluminescence - Night Photography Puerto Rico |
Canon EOS 60Da • EF 16–35mm f/2.8L II USM • 4 sec • ISO 12800 • f/2.8
Bioluminescent astrophotography exists at the intersection of Earth and sky. Moments like this — when plankton responds to motion below while galaxies shine above — remind us that some of the most extraordinary night-time experiences happen not only in the cosmos, but right here on our own planet.
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