Growing up in southern New York, Long Island beaches were frequent destinations for me during the summer months. For years I played in the dark water, sometimes appearing almost greenish, and thought nothing of it. It wasn’t until I began visiting tropical destination, like the Caribbean islands, and saw the sparkling light aqua water that I began to realize the drastic differences in ocean water color. Recently as I’ve been studying oceanography in school, the topic of color has come up time and time again.
Many factors, such as ocean depth, contribute to ocean color, but one major cause of darker oceans is the overproduction of phytoplankton. Chlorophyll, an important light-absorbing substance, is used by phytoplankton to produce carbon during photosynthesis. The green pigment of this substance causes phytoplankton to reflect green light, making areas with high algae production appear much darker, with a slight greenish hue, than other oceanic locations.
When toxins and waste are released into the ocean many species are killed off while the growth of others are encouraged. Nitrogen and phosphorous are two elements frequently discharged into coastal waters from sewage waste and runoff containing fertilizers. New York City, for example, is a large source of the sewage wastewater that contributes to nutrient pollution in Long Island Sound. Excess nutrients can result in explosive toxic algal blooms, which are accompanied by human and marine illnesses from ingestion of shellfish containing toxins.
On the other hand, polychlorinated byphenyls (PCBs) are a critical compound found in the ocean that can destroy nontoxic plankton populations. This compound is often found in plastics and rubber, however, it is unclear whether pollutants can seep from plastic debris into the organisms that consume them. Nevertheless, plankton populations are to known to absorb PCBs released into the ocean in other ways. This compound can negatively impacts these species, as seen in the contamination and decline of zooplankton in some areas.
Using technology such as SeaWiFS, scientists are able to measure ocean characteristics like ocean color, chlorophyll concentration, and water clarity. Studying ocean color allows for scientists to gain an understanding of the relationship between marine debris and pollution and phytoplankton production. Once again, research in this area has indicated that the less debris in the ocean means the healthier the ecosystem!
"Ocean Color Web." NASA. National Aeronautics and Space Administration, 17 02 2012. Web. 10 Apr 2012.
"Plastic Marine Debris: What we know." NOAA Marine Debris Program. National Oceanic and Atmospheric Association, 21 09 2011. Web. 10 Apr 2012.