Underwater fluorescence with Philippe Cousteau and BBC Oceans

Philippe Cousteau and the team dive in the Red Sea, one of the warmest seas in the world. Despite the warm temperatures, coral reefs flourish with their flourescent pigmentation putting on an amazing show of technicolour. Fantastic clip taken from the BBC Oceans series.

Philippe is one of the grandsons of Jacques Cousteau, and the cousin of Mission 31’s Fabien Cousteau.

And though it looks like they’re using black lights—and though ultraviolet light (black light) does work—it appears that the blue lights they are using can be more effective for seeing these displays. A report from NightSea.com:

“There is no one light that will make everything fluoresce, but if you want to choose a light to give you the most varied and vibrant fluorescence experience blue is the way to go…

“Eventually I had access to a spectrofluorometer, an instrument that can measure the excitation spectrum. This is essentially a graph of the relative ability of different wavelengths of input light to cause something to fluoresce. The spectrofluorometer monitors one wavelength of output and sweeps through a range of excitation wavelengths with very fine resolution. When I started measuring excitation spectra I saw graphs like the one… I knew that UV would make the coral fluoresce since that is how I located the specimen in the first place, and you can see a bump in the UV region in the plot. But according to the graph, blue light should be more efficient at making the specimen fluoresce.”

Watch more about fluorescence and more coral videos.