Estuaries are bodies of water where the ocean’s salinity mixes with the rivers’ freshwater. These bodies of water provide an excellent environment for various types of water creatures, plants and other organisms to thrive in. The estuaries could differ in their stratification depending on how the salinity of the sea water mixes with the fresh river water. The seawater, because of its salt content, would trap nutrients carried by the river, producing salt wedges where different organisms could exist abundantly. That is why estuaries are rich sources of healthy food for man; hence, man should ensure they do not disappear from the environment. These rich water areas might be endangered because of these reasons:
Development introduces pollutants to estuaries
According to a report by Creative Loafing, the Tampa Bay Estuary’s sea grasses and mangroves have decimated over time because of development. “Dredging and filling shorelines for development,” and nitrogen enrichment in the environment have started to destroy the estuary. The reduced volume of sea grass also decreases the capacity of the estuary to filter pollutants that could destroy its biota. Nitrogen prevents sunlight from reaching the sea grasses, which is vital to their growth.
A report from Restore America’s Estuaries revealed that at Narragansett Bay, the estuary’s fish dwindled because of “watershed over-development.” Other estuaries, such as San Francisco Bay’s wetlands and Galveston Bay's sea grass meadows, are also being destroyed slowly.
Human and animal wastes flow to estuaries
Increasing numbers of septic tanks containing human and animal wastes are now flowing into the ocean through estuaries, polluting some of the existing biota. There are harmful bacteria and protozoans existing in human wastes that could cause illnesses in estuary fishes and other organisms. This would eventually reach humans through the food chain, and could cause illnesses, as well.
Heavy metals like mercury, lead and copper coming from Gulf Coast waters pollute estuaries
These heavy metals are not only harmful to fishes and to the estuary’s biota, but these are also harmful to man, causing serious health problems, including death. These pollutants may come from pesticides, paints, batteries and other industrial end-products. This is especially true in estuaries located near economically developing areas.
With development comes a corresponding additional responsibility, the responsibility of preserving the Earth’s estuaries. Everyone should join hands and contribute in the preservation of nature’s great gift to the ecosystem. When people are aware that estuaries help maintain the balance of the ecosystem, and that they help provide food, then they may help in the preservation of these important areas.