Water is essentially a color liquid. But some bodies of water turn either green , dark blue, light blue, etc. Read to find out how these colors form!
Introduction to Wavelengths of light
If you ever traveled on boat further away from sea, you know that the the ocean gets deeper and blue each time. This is because there are no reflections on the sea floor and the natural light is made up of numerous different colors associated with different wave lengths of light. Light reflecting the surface of the water is depended on the state of water itself.
For example, less light will be reflected on the ocean's surface if the water is calm and smooth. However, more light occurs when there are more waves and it is turbulent. Red, yellow, and orange are longer wavelengths of the spectrum and can penetrate to approximately "15", "30", and "50" meters. While, violet, blue, and green are shorter wavelengths of the spectrum can penetrate to lower limits of the sunlight zone.
The shorter wavelength, blue, is the reason why the color blue penetrates the deepest and appears most of the time. Sea water close to shore may appear more green or brown in color because water in shallow areas tends to contain greater amount of particles that scatter. Overall, the the color of the water is primarily due to the reflection of different wavelengths of visible light.
Wildlife in the Water
Sometimes you look at the water and it often appears gray. The grayish-looking water is often due to living organisms in the sea. Organisms include phytoplankton (algae), zooplankton, jellyfish, and other wandering animals. Particles such as sand and slit can add to the water's obscurity. This can cause the water to be easily agitated and stay floating in the water for long periods.
Sediments is also another factor that plays a role in the color of the water. Sediments are made up of pieces such as shells and chunks of dead coral. The pieces of shells and chunks of dead coral are tougher to stir up in the ocean. As a result, an algae turf (also known as algal blooms) begin to grow over the dead coral. Algal blooms turn the water green, brown, and red. The result of algal blooms can cause water quality problems, lead to the decline of oxygen levels, and can even block sunlight from underwater plants. The problems only arise if there is an overgrowth of algae in a short period of time.
Key Takeaways
- Across the spectrum, wavelength decreases and energy increases as you move from red to violet light.
- The color of light to penetrate through water the best: 1st: Blue, 2nd: Green, 3rd: Yellow, 4th: Orange, 5th: Red
- Black animals absorb all colors of light in the twilight zone and red animals appear black as there is no reflection of light.
- The blue animals in the midwater regions of the ocean would be highly visible to predators because their bodies reflect the blue light.
- The water may appear more blue-green to emerald green based on the type of phytoplankton.
- In water, the red light is absorbed quickly because absorption is strong leaving the ocean blue. (absorption is weak in blue in water)
References:
“What Makes a River Different Colors.” American Rivers, 15 May 2019, https://www.americanrivers.org/rivers/discover-your-river/river-colors/.
Brodwin, Erin. “Here's Why Some Beaches Have Crystal-Clear Water and Others Are Murky and Gray.” Business Insider, Business Insider, 12 July 2016, https://www.businessinsider.com/why-some-beaches-have-clear-blue-water-and-others-are-gray-2016-7?r=US&IR=T.
McGough, Will. “How Can Bodies of Water Be Different Colors?” Mental Floss, Mental Floss, 17 June 2013, https://www.mentalfloss.com/article/50384/how-can-bodies-water-be-different-colors.
US Department of Commerce, National Oceanic and Atmospheric Administration. “Why Are so Many Deep-Sea Animals Red in Color?” Ocean Exploration Facts: NOAA Office of Ocean Exploration and Research, 25 Mar. 2014, https://oceanexplorer.noaa.gov/facts/red-color.html.
“Light Transmission in the Ocean.” Water Encyclopedia, http://www.waterencyclopedia.com/La-Mi/Light-Transmission-in-the-Ocean.html#:~:text=The%20long%20wavelengths%20of%20the,limits%20of%20the%20euphotic%20zone.
Written by: Mehr Chandok