Light in the Deep Sea

marinebio.org

Photos courtesy of Heather Austin

Going down to 2,000 feet in the ocean!

Light outside my window…

300 ft

550 ft

2,000 ft!

Video Monitor Screen

Photos courtesy of Heather Austin

What Happens to Light As it Passes Through the Ocean?

•Sunlight produces a visible spectrum of the colors: red, orange, yellow, green, blue and violet

•These colors combined together appear white

•Water absorbs light.

•It does this by absorbing the longer (or lower energy wavelengths first)

•So…Red gets absorbed first

•Blue penetrates deepest

•Exception is violet light. It is the shortest wavelength and highest energy BUT it gets scattered by particles in the water.

http://www.noc.soton.ac.uk/JRD/SCHOOL/mt/mt001b_2.html

disc.sci.gsfc.nasa.gov

How Do Animals Adapt to Living in Little or No Light?

They can…

1. Counter-illuminate: Animals use light-producing organs on their underside. They increase the light level underneath themselves as they move up into shallower water where they are silhouetted against the sky and dim it as they descend to deeper water.

2. Bioluminescence to escape predators: Some animals, such as deepwater shrimp, vomit bioluminescent clouds, while some copepods emit bioluminescent clouds from their posterior ends.

http://www.tufts.edu/alumni/magazine/fall2007/features/oceans.html

http://www.lifesci.ucsb.edu/~biolum/