Have you ever noticed flashes of light as you quickly moved your hand through the water on a night dive at Ship Rock? Or when sitting at the back of a dive boat, have you noticed the sparkly trail left behind in the water disturbed by the engine? These mesmerising sights are the work of bioluminescence! You were not hallucinating but simply saw lots of tiny organisms using one of the more spectacular adaptations at the disposal of many marine creatures.
Bioluminescence is the name for the light produced by some animals and is the result of a chemical reaction. Some animals make the necessary chemicals themselves, some absorb them from their food and others allow bioluminescent organisms to live inside them forming a symbiotic relationship. Some bioluminescent animals live on land but the majority are found in the ocean. Most sea animals emit bioluminescence in the blue-green range, while the land lubbers tend to emit light in the yellow range of the colour spectrum.
Bioluminescence has different purposes for different animals. Some use bioluminescence to startle their prey. You may have seen the cuttlefish at Oak Park use this mechanism. They appear to flash different colours when they feel threatened. Sea cucumbers have the ability to break off luminescent bits of themselves onto other animals with the hope that their predator will follow the glowing detachment instead of eating them for dinner!
The most famous sea creature to use bioluminescence is the Angler fish. The Angler fish has a growth that looks a lot like a ball on the end of a fishing rod which hangs over its head near its mouth. The Angler fish can light up the ball to lure curious prey towards its gaping jaws.
The best way to catch a glimpse of bioluminescence for yourself is to come along to the next Abyss night dive. Check out the dive calendar for dates.