Bioluminescence Amongst Deep Sea Creatures

The deep sea is a vast and unknown chasm full of animals yet to be discovered by humans. One amazing capability of animals is bioluminescence, the biochemical emission of light. Though the firefly is usually the first animal that comes to mind, there are so many more deep sea creatures with the same ability. What makes bioluminescence so important? According to a recent study on the quantification of bioluminescence from the surface to the deep sea conducted by researchers Séverine Martini and Steve Haddock from MBARI (Monterey Bay Research Institution), “In marine environments, the presence of light plays a major role in the spatial distribution of marine communities”. The sun provides light for sea creatures near the surface, which feeds the ecosystem. However, how can deep sea creatures survive in areas where sunlight cannot permeate through the water? These creatures make up for the lack of natural light by emitting their own “cold light”, made from a biologically generated chemical reaction that produces said light.

While creatures just off our coast are less likely to be bioluminescent, venture deeper into the ocean and the percentage of bioluminescent fish drastically increases. In the Eastern Northern Atlantic, around 90% of fish observed below the depth of 500 metres are bioluminescent (Herring, 2002). The famous angler fish is a prominent example of bioluminescence in fish, as it uses its light to lure prey. Almost all light produced from bioluminescent creatures is blue, so the specially adapted skin on the angler fish reflects blue light — making it invisible from its own light.

Though one might suspect that bioluminescence is rare amongst many sea creatures and only found in deep sea creatures, it occurs quite frequently in other animals such as squids, jellies, and worms. Martini and Haddock stated in their study that, “76% of oceanic marine organisms observed in deep waters offshore of California have the capability of bioluminescence.” All research was conducted right off our Monterey Bay using ROV robots. Therefore, because there is such an enormous diversity amongst creatures with the capacity of bioluminescence, we can conclude that bioluminescence serves many extremely important ecological roles (Haddock, 2010).