Factors That Affect the Health of a Freshwater Ecosystem

Freshwater ecosystems, ecosystems that contain drinkable water with little or no salt content, are vital habitats that not only act as focal points of biodiversity but also determine the conditions of freshwater delivery and purity to other ecosystems. These ecosystems are also among the most threatened natural spaces on Earth, with a variety of factors affecting their health and endangering their survival.

Plant and Animal Biodiversity

• Changes in the concentration and diversity of species in a freshwater ecosystem can fundamentally alter the dynamics of the habitat. Several plant species, like grasses in still wetlands, not only play an important role in the food chain of the system but contribute to the filtration of water. Similarly, animal species like oysters also clean and purify water as part of their life functions. Thus, changes in the species diversity from hunting or contamination can alter ecosystem dynamics and the quality of water in the system.

Microbiological Factors

• Although effects to larger plant and animal species generate more visible changes in an ecosystem, microbiological life, such as bacteria, also plays a critical role in an ecosystem. As microbiological life forms tend to be very fragile and more responsive to changes in the ecosystem, changes in the microbiological makeup can be among the first signs of an ecosystem in trouble. Many biologists even use microbiological samples as a first test for deterioration in an ecosystem. As conditions like the amount of oxygen dissolved in the water change, the composition of bacteria in the water changes to adapt to the new situation, which in turn changes the kinds of waste materials the new microorganism excrete into the water and can reduce the quality of the water and the ecosystem as a whole.

Climate

• Freshwater ecosystems and wetlands are highly dependent on a regular water cycle for their survival. As changes in climate alter temperatures or frequencies and amounts of precipitation, the amount of water entering and leaving the system can change rapidly. If a freshwater ecosystem becomes more dry or more humid, the kinds of plants and animals that can survive in the system changes and the health of the ecosystem in its previous form can deteriorate.

Changes in Terrain and Hydrology

• Human development is one of the major culprits of deterioration due to changes in terrain and hydrology. When, for instance, wetlands are drained and developed for human habitation or use, most species that depended on the humidity in the habitat for their survival either die out or move to other habitats. The water previously found in the ecosystem, however, continues its natural cycle, either flooding settled areas periodically or flowing into other ecosystems to change the water dynamics elsewhere.

Chemical Contamination

• One of the most common problems in freshwater ecosystems, chemical contamination from industrial or residential human activity can dramatically impact biological dynamics. Chemicals like mercury and arsenic from industrial production or even other chemicals from soaps, fertilizers and fuels from human activity can make an environment unsuitable for certain organisms and adversely affect water quality. Even organic wastes, when in large quantities, can alter the food chain and upset the fragile balance of an ecosystem.