Fresh water-types of water found on earth, Biology

Fresh Water

Water, a universal solvent, invariably contains many soluble salts. In fresh water the total salt content remains under 15 percent. Different types of soluble salts released by weathering of rocks, soil erosion and decay of organic matter, readily dissolve in water.Dissolved salts are substances which have particular significance for floating aquatic vegetation and phytoplankton, since these organisms do not depend on the substratum for the supply of nutrients. Salts of nitrogen, phosphorus and silicon are most important substances found dissolved in fresh water. Nitrates, nitrites and ammonium salts are essential nutrients for plants. Dissolved silicates in the water are readily utilised by diatoms and sponges in the construction of their body structures e.g. shells in case of diatoms and spicules in case of sponges.

Many other elements like calcium, magnesium, manganese, iron, sodium, potassium, sulphur and zinc are found dissolved in water and influence the aquatic biota variously. Iron being an essential nutrient exists as ferrous oxide or ferrous sulphide in different fresh water bodies. Its availability is greatly modified by the pH of medium. Calcium is an essential element for plants as well as for animals. External coverings of arthopods and shells of molluscs and tubes of some worms need calcium carbonate.

Posted Date: 12/11/2012 12:24:13 AM | Location : United States







Related Discussions:- Fresh water-types of water found on earth, Assignment Help, Ask Question on Fresh water-types of water found on earth, Get Answer, Expert's Help, Fresh water-types of water found on earth Discussions

Write discussion on Fresh water-types of water found on earth
Your posts are moderated
Related Questions
What is osteoblast The osteoblast is the key for the development of new bone. It is essential that a large number of osteoblasts accumulate on the implant surface(contact osteo

Is crossing over important for the diversity of biological evolution? Sexual reproduction and recombination of linked genes (crossing over) are, with mutations, the main instru

what is ecology

CHARACTERISTICS OF FEMALE'S SKELETON - 1.      Skull is lighter. 2.      Shoulders are nanow. 3.      Sacrum is shorter but wider. 4.      Pelvis is wider. 5.

Explain the term 'health' Mention any two ways of maintaining it. Why does a doctor administer tetanus antitoxin and not a tetanus vaccine to a child Injured in a roadside acci

Q. What are the main intraspecific ecological interactions? The major harmonious intraspecific ecological interactions are societies and colonies. The major inharmonious intras

What is Waist-to-Hip Ratio? Waist-to-Hip Ratio (WHR) is defined as the measurement of waist circumference divided by hip circumference. For example, if a person's waist measure

Q. Type specimen of class enteropneusta? Examine the specimen and note the following features: 1. Balanoglossus has a soft, elongated, worm-like body which has a ciliated surf


Define Objective of Taxonomy - Assemblage of Knowledge Gained? A second objective of taxonomy is the assemblage of knowledge gained. This is usually in the form of treatises us