How Does UV Light Affect the Ocean?

UV Light Radiation

Ultraviolet (UV) light is similar to visible light, but travels on a shorter wavelength. Most UV light is reflected or blocked out by the earth's ozone. Yet with recent threats of the ozone layer depleting in larger areas, the danger of overexposure to UV light takes on a greater significance.

Identification

Light radiation from the sun is composed of several different wavelengths, which have various properties. Ultraviolet light that reaches the ocean plays an important role for marine animals at all levels of the food chain.

Significance

Most marine species living in the upper levels of the ocean require sunlight for photosynthesis, but an overexposure of UV light can destroy microorganisms called phytoplankton. This causes a cascade effect that disrupts the entire marine ecosystem.

Sensitive Areas

NAS, a NASA research website reports that phytoplankton in arctic areas are more susceptible to the harmful effects of UV light radiation. A field survey of Antarctic phytoplankton near the springtime ozone hole found a 6 to 12 percent drop in phytoplankton productivity.

Growth Rate

UV light causes plankton to sink to deeper depths of the ocean, which inhibits their reproduction and growth rate.

Prevention/Solution

Some marine organisms have adapted mechanisms that protect them from UV light radiation. These creatures have evolved UV absorbent pigments in their skin, and in the most exotic cases, even the ability to repair UV damaged DNA on the cellular level.

References

• Ultraviolet Waves: NASA
• UV Radiation: NASA
• Light in the Ocean: WHOI Oceanus

Resources

• Ultraviolet Effects on Phytoplankton: Photobiological Sciences Online