By Barbara Whitman One of the greatest joys in my life is a hot shower.” But whenever we visited the cabin in New Hampshire over Christmas vacation I knew that a hot shower at the end of a day of skiing was both a joy and a pain in the neck.” The pipes at the cabin were used only during periodic visits and on the first few forays into the bathroom we were literally showered in rust.” Tiny flecks of reddish metal would accompany the water through the showerhead and even vigorous rubbing could not get rid of the little orange speckles.” I didn’t really mind since I figured every ounce of extra energy I expended deflecking would mean another calorie burned and a little less of me to go around.” For me expending calories is a good thing.” For corals ” not so much. Because corals don’t have towels, they use mucous, their subsea version of a force shield, to get rid of unwanted material.” Every time they have to manufacture mucous to push away potentially harmful attacks, they have to use energy ” energy that would otherwise be put to good use collecting food or reproducing.” Think about it: Wouldn’t you rather be eating or having a good time rather than cleaning house? Corals constantly under assault have to continue to rob Peter to pay Paul ” that is, to take calories away from growth, a healthy immune system and reproduction and use it for self defense instead.” Eventually they will become so weak that they will not have the strength to ward off disease and ultimately they will perish. This is what is happening along our coasts.” Why?” Well there are a variety of reasons.” One of the biggest reasons is sediment ” yup, just plain dirt:” Dirt that comes from the land.” How does it get into the water?” Gravity.” Okay it’s a little more complex than that. Have you ever taken a walk in the rainforest?”” It has an incredible smell: rich and moist.” A lot of that pleasant aroma is the scent of damp dirt.” You can almost tell from the smell that the soil is thick and moist, composed of minerals from countless raindrops patiently wearing away the rocks and from leaves and trees and bits of fruit that have returned to the earth after falling to the ground.” This thick layer of dirt cleans water ” an oxymoron if ever I heard one.” The rich earth acts as a filter removing impurities from the water.” The water that flows down the ghauts from the rainforest, under normal circumstances, is clear and clean of sediment.” It is also clear partially because trees, plants, grasses and other ground cover keep loose dirt from running into the water by trapping it in their roots and stems.” They keep rich topsoil, well, on the top. Picture the rich foliage of “Lost.” Then along come humans.” We cut down the trees and bushes and clear large areas of land to build on.” We raise goats, pigs, sheep and cattle who roam around grazing on plants, reducing soil stabilizing foliage.” The once moist soil becomes dry and hard from exposure to the sun and wind.” Picture “Little House on the Prairie” with all that dust blowing across the dry plains.” The land no longer has plants to keep the dirt in place and when it rains gravity transports rivulets of mud to the sea on to the corals.” The normally clear water becomes murky, both blocking out the sunlight and introducing vast quantities of dirt that belongs on land into the ocean. Our brave little corals do their best to protect themselves from the onslaught.” They direct all their energy into removing the muck.” Their zooxanthellae (remember the little symbiotic algae that give coral its color and provide it with food?) can no longer photosynthesize because there isn’t enough “photo” (that means “light” in science speak) to ‘synthesize” (that means “cook up in the kitchen”) food.” There is no light because the mucky water prevents sunlight from entering.” It’s a dirty shame and it only gets worse. It wouldn’t be so bad if this only happened every so often because the corals would recover and the currents would eventually take away a lot of the silt.” That’s why many decades ago the corals were just fine.” The problem now is that there is a great deal of construction on the island and out into the water.” There are even more sheep and goats and other grazers that nibble the soil stabilizers.” There is dredging.” There are quarries.” There are groins, jetties and docks that restrict the flow of currents that would normally wash away all this runoff.” And, to top it off, we don’t have anything in place to keep these things from getting into the water in the first place. No matter how beautifully wrapped, if all these were put into a box together they would be one nasty Christmas gift for the corals. This is the gift that keeps on giving.The rains wash the soil into the sea.” The corals redirect their energy resources to secrete thick layers of mucous to protect themselves and their little zooxanthellae stop making food ” a net decrease in energy for coral growth, health and reproduction. The heavy sediments settle to the bottom.” The finer ones, oddly enough, go even deeper falling down between the coarse grains of sand to create a mucky layer beneath.” Every time the sea is stirred up this silt is resuspended in the water and the process is repeated.” You may ask, what’s the big deal?” Storms have been stirring up the seas since the beginning of time.” The big deal is that sand, which belongs in the sea, settles out quickly after a storm.” Dirt and silt, which do not belong in the sea, take much longer to sink to the bottom because they are lighter.” That spells longer periods of dirty water, more time for the corals to try and keep themselves clean and less time for their symbiotic algae to make food for them.” In a nutshell, it means more stress on the corals.” And we all know nowadays that stress leads to health issues, even in corals. The next time it rains heavily, look at the sea.” You can see trails of dirt running into the water from the ghauts.” You can see the plume spread with the currents and join the silt which has been churned up from under the sand.” And if you look now with an informed eye, you can see that the bays and other areas that have structures blocking the flow of currents remain darker longer.” Much of the dirt never escapes.” It simply settles below the sand or remains to plague the few corals that have been struggling to survive the onslaught.” And every time the waves beat and churn along the coast the muck darkens the water and the little corals begin their battle all over again. (Barb Whitman is a marine biologist, educator and proprietor of “Under the Sea,” located at Oualie Beach. For more information, call 869-662-9291.)
