UPSC Prelims 1998 · General Studies
Question 54: Environment and Ecology
Estuaries possess distinct blooms of excessive growth of a pigmented dinoflagellate. These blooms are called
AnswerThe answer is (a).
Red tides are blooms of excessive growth of pigmented dinoflagellates such as Gonyaulax (Alexandrium) in coastal waters and estuaries, which colour the water reddish-brown. Some species release toxins that kill fish and poison people who eat contaminated shellfish. Blooms are fed by nutrients washed in from land, and the resulting oxygen loss adds to the damage. Sea tides, black tides and sea flowers are not terms for this.
Why each option is right or wrong
- (a) Right: dinoflagellate blooms are called red tides.
- (b) Sea tides are movements of water caused by the Moon and Sun.
- (c) Black tides is not the term for algal blooms.
- (d) Sea flowers is not the term for algal blooms.
Explanation: written by UPSC Grade, not by UPSC.
Source: UPSC, Civil Services (Preliminary) Examination 1998, General Studies. UPSC's own paper isn't online; the words are from a published compilation. The paper on upsc.gov.in.