Abiotic and Biotic Factors
Abiotic factors are essentially non-living components that effect the living organisms of the freshwater community.
Both Abiotic and Biotic factors determine both where an organism can live and how much a population can grow. Abiotic Factors
When an ecosystem is barren and unoccupied, new organisms colonizing the environment rely on favorable environmental conditions in the area to allow them to successfully live and reproduce.
These environmental factors are Abiotic factors. When a variety of species are present in such an ecosystem, the consequent actions of these species can affect the lives of fellow species in the area, these factors are deemed Biotic factors.All species within an ecosystem will experience some kind of limiting factors to prevent continuous and exponential growth.(Even Humans)
These are the physical and chemical elements that make up a habitat. The main ones are 1. Temperature 2. Level of carbon dioxide 3. Intensity of light. Although many of the factors are shared with all freshwater habitats moving water has speed of flow as a major additional consideration.
We have just considered the background to abiota and some of the factors you might think about and why. However, the main factors to concentrate on in freshwater are:
The size at which The size at which a theoretical population would stabilize, indicated as "K" on the graph in the previous section, is referred to as the carrying capacity. The carrying capacity is the theoretical equilibrium population size at which a particular population in a particular environment will stabilize when its supply of resources remains constant. It can also be thought of as the maximum sustainable population size; the maximum size that can be supported indefinitely into the future without degrading the environment for future generations.
Most organisms can do little to change the carrying capacity of their environments, but humans have. The historical pattern of human population growth shows the effect of breakthroughs that essentially allowed increases in K. As examples, the switch from hunter/gatherer societies to agricultural societies with increasingly intensive agriculture, technological advances that allowed us to inhabit new places (irrigation, heating) and use new resources to increase food production, all increased the effective carrying capacity for humans. These filtration systems work wonderfully in a perfect world.But,of course, filters (and the World) are not perfect; the water does not re-enter the aquarium in the same state as it first did. The water is changed by the filtration process, and it is these changes that limit increased fish numbers.
The first limiting factor in a fish system is not the presence of ammonia, nitrite or even pH (more about them later),but oxygen. Fish must have oxygen to breathe. The more fish in the water, the more oxygen that must be supplied. But, fish are not the only consumers of oxygen in an aquarium. Bacteria also consumes a major portion of the oxygen. As fish numbers increase, there is more ammonia to oxidize, more waste to mineralize, and more bacteria needed to perform these tacks.The first limiting factor in a fishy stem is not the presence of ammonia,nitrite or even pH (more about them later), but oxygen. Fish must have oxygen to breathe. Fish must have oxygen to breathe. The more fish in the water, the more oxygen that must be supplied. But fish are not the only consumers of oxygen in an aquarium. Bacteria also consume a major portion of the oxygen. As fish numbers increase, there is more ammonia to oxidize, more waste to mineralize, and more bacteria needed to perform these tasks. More bacteria and increased bacterial activity require yet more oxygen. Fortunately, oxygen is relatively easy to provide in aquariums. The most effective oxygen-generating methods create a lot of water surface agitation which is where gas exchange takes place.