Question
Download Solution PDFOligotrophic lakes are characterized by:
Answer (Detailed Solution Below)
Detailed Solution
Download Solution PDFLake ageing is the natural process by which a lake fills in with erosional materials carried in by tributary streams, with materials deposited directly from the atmosphere and with materials produced within the lake itself.
Classification of Lakes: A lake can be classified by its “age.” i.e. Lakes are classified by their trophic state. The word “trophy” refers to ‘nutrient status’, therefore, lakes are classified based on the number of available nutrients (Phosphorus and Nitrogen) for organisms, the chlorophyll and transparency.
Lakes are divided into Three Trophic Categories:
|
Oligotrophic |
Mesotrophic |
Eutrophic |
|
“Oligo” means little. Thus, oligotrophic means low levels of nutrients (Phosphorus and Nitrogen) and low levels of primary productivity |
“Meso” means middle. Thus, mesotrophic means intermediate levels of phosphorus and primary productivity |
“Eu” means true. Thus, eutrophic means truly nutrient-rich. High phosphorus concentrations and high levels of primary productivity |
|
Deep lakes with excellent water clarity and rocky/sandy bottoms with limited growth of algae |
Moderate water clarity with some algal blooms |
Shallow lakes with poor water clarity and soft bottoms with lots of algae |
|
Well-oxygenated (water at lower depths) |
Moderate levels of dissolved oxygen |
Low dissolved oxygen |
|
Very few aquatic plants |
Moderate plant growth |
Extensive aquatic life |
|
Supports cold water fish species |
Usually supports warm water fish species |
Only warm water fish species |
Hence, it can be said from the given points that oligotrophic lakes are characterized by a low level of nutrients.
Last updated on Jun 12, 2025
-> The UGC NET June 2025 exam will be conducted from 25th to 29th June 2025.
-> The UGC-NET exam takes place for 85 subjects, to determine the eligibility for 'Junior Research Fellowship’ and ‘Assistant Professor’ posts, as well as for PhD. admissions.
-> The exam is conducted bi-annually - in June and December cycles.
-> The exam comprises two papers - Paper I and Paper II. Paper I consists of 50 questions and Paper II consists of 100 questions.
-> The candidates who are preparing for the exam can check the UGC NET Previous Year Papers and UGC NET Test Series to boost their preparations.