Posted by admin | 11.15.2012 | Marine Science
Today’s Forecast: Marine Snow?
Not your typical weather pattern. Marine snow has little in common with its atmospheric counterpart. It is composed mainly of dead or dying organisms, fecal matter, and gelatinous mucus. Not something you’d typically want to ball up and toss at your friends face during the annual Christmas snowball fight. Despite seemingly unpleasant qualities marine snow is just as unique as those icy white crystals and more valuable ecologically. On the other hand it probably wouldn’t make the best snow cone.
Scientifically, marine snow refers to the continuous downward drizzle of organic debris from the light-rich photic level to the aphotic, or light absent, ocean floor. On average light only penetrates the top 200 meters of ocean so any organisms living deeper must rely on some pretty unorthodox energy sources, including ocean detritus. Marine snow is just one such example of deep sea animals obtaining the resources they need to survive in resource-poor environment. The organic particles in marine snow supply the primary source of carbon for these deep water dwellers, since without light they are unable to photosynthesize.
Debris particles range from microscopic to whale size (literally!)and are responsible for nourishing a large array of organisms.Small particles make up the majority of marine snow, but occasionally scientists discover a underwater phenomenon called “whale fall”. Whale falls occur when the animal dies and sinks to the seabed. The decaying flesh attracts organism from miles around; one carcass can create and sustain its own underwater community for decades.
Smaller particles of marine snow are prevented from “falling” directly to the ocean floor due to the natural buoyancy of the ocean. For that reason, the process of repetitive ingestion and egestion is essential to the carbon transfer in the oceanic water column. Particles in the photic zone, such as phytoplankton, are digested and excreted in the surface levels of the ocean. These fecal pellets are more dense and they tend to lump together, so the sinking process begins. This passive process will happen over and over; particles are continually eaten and pooped out. Up-and-down, up-and-down, they move in the water column transferring energy, it is astonishing that they ever reach the seafloor, which can be miles below.
Three-quarters of the deep ocean floor is covered in thick marine ooze which is composed of many things, it is suspected not much marine snow makes it this deep, but once it finally does it continues to breakdown through biological activity. This blanket of ooze took billions of years to accumulate in on average 1,000 feet deep, but it can be up to 6.2 miles thick, so who’s up for marine snow angels?