Differences in Aquatic Ecosystems
Freshwater
- Freshwater covers less than 1% of earth's surface, but is home to 35% of all vertebrate species.
- In the United States nearly half of the 573 animals on the threatened and endangered species list are freshwater species.
- More than 30 years after the Clean Water Act promised clean water, an overwhelming majority of Americans live within 10 miles of a polluted river, lake, or coastal water. These waterways are unsafe for fishing, swimming, or aquatic life.
Examples: The Amazon River, Mississippi River
Piranha
Notorious for their sharp teeth and voracious appetites, piranhas inhabit several of the major river basins in South America.
Nile Crocodile
These large reptiles are distributed across much of Africa, and they have earned their reputation as among the most ferocious, deadly animals on the planet.
Mata Mata
A mata mata (Chelus fimbriatus) is a freshwater turtle that inhabits the Amazon and Orinoco basins in South America. The bizarre turtles are entirely aquatic, although they prefer shallow, stagnant water, where they can easily reach their head out of water to breathe.
Giant Catfish
The largest on record is the Mekong giant catfish, which has reached recorded sizes up to 10.5 feet (3.2 meters) and 660 pounds (300 kilograms). Once distributed across several countries in Southeast Asia, the Mekong giant catfish is now critically endangered, thanks to habitat disruption. Not much is known about the world's biggest freshwater fish, although conservation efforts are underway.
Anaconda
Among the world's largest snakes, anacondas live in rivers and wetlands of South America. The word anaconda is thought to come from the Tamil word anaikolra, which means elephant killer, alluding to the reptile's fearsome reputation.
Vampire Fish
Vampire fish prey primarily on smaller fish, especially piranhas, which they impale with their long, sharp fangs. The intimidating teeth can grow up to six inches long.
Brackish Water
- Brackish water or briny water is water that has more salinity than fresh water, but not as much as seawater. It may result from mixing of seawater with fresh water.
- The word comes from the Middle Dutch root "brak," meaning "salty". Certain human activities can produce brackish water, in particular certain civil engineering projects such as dikes and the flooding of coastal marshland to produce brackish water pools for freshwater prawn farming.
- Brackish water is also the primary waste product of the salinity gradient power process. Because brackish water is hostile to the growth of most terrestrial plant species, without appropriate management it is damaging to the environment.
Examples: The Amazon Delta, The Mississippi River Delta
Salt Water
- Saltwater ecosystems include a wide array of vastly different ecosystems, with at least one major similarity -- saltwater. The plant life, animal life and land structures that make up saltwater ecosystems also are varied. These ecosystems can best be characterized according to their locations.
- Saltwater ecosystems can be divided into oceans, estuaries, coral reefs and shorelines; each of these having a diversity of characteristics.
- All of saltwater ecosystems have landforms, plant life and animal life, which may be unique to their location. Although these saltwater ecosystems are very different, they share high degree of interdependency by the nature of their association.
Examples: Atlantic Ocean, Pacific Ocean