Threats To Seagrass Community
Seagrass beds are fighting for their lives. Many forces are working together to destroy our valuable seagrass communities. One of the biggest problem is human sewage. It overflows inadequate septic tanks and seeps into the sea, or it flows into rivers during rainy periods. Sometimes it is even emptied directly into the sea through pipes!
Chemicals present in the sewage cause a lot of problems in the sea, as they are nutrients for algae, which multiply rapidly when exposed to them. When the algae eventually die, bacteria begin to decompose them, but in order to decompose all this algae, the bacteria need a lot of oxygen. The bacteria remove the oxygen from the water, reducing the amount of oxygen for other marine life. As algae and bacteria build up in the water, it becomes harder for sunlight to pass through the water, which makes it harder for seagrass to produce fresh oxygen through photosynthesis. The bacteria may eventually use up all the oxygen in the water. Seagrasses and marine animals (including manatees) would then die!
Garbage also poses a problem to seagrass beds, since much of our garbage contains poisonous chemicals which sometimes seep into ground water or rivers, and eventually reach the sea. Plastics are also another garbage problem, as the dropped bags or bottles are blown around in the wind and can eventually wash into rivers and the sea, where they can be accidentally ingested by the manatees or other marine animals. They could then choke on the plastic and die! Aerial spraying is especially harmful, because undiluted poisons can be carried by wind directly to the sea. We need to be extremely careful how we go about our daily lives, as we could affect other life forms which cannot protect themselves from us!