Following enlisted are the answers for the above mentioned question.
Explanation:
1. Population pyramids is graphical representation of data which enables oneself to distinguish and have a clear picture in minds about the ratio of population densities keeping any one parameter as constant. Population pyramids could be used to analyze data in many different scales on the basis of gender,age groups, race etc. Examples-having a record of no. of individuals in different age groups in India.
2. Generally, there are 3 types of population pyramid on the basis of shapes of the pyramid. Those are;
- Expansive
- Constrictive
- Stable
Siting an example of age-sex pyramids,
In case of the Expansive, population pyramids show that the populations that have a larger number of persons in young age groups. The shape obtained hence is usually with high fertility rates with lower death rates
Then comes, Constrictive population pyramids. These are named so since they are constricted at the bottom. They undue a low percent of young people as compared with other age groups. These type of pyramids show decreasing birth rates.
And at last, Stationary also called as stable population pyramids are the ones which depicts almost equal proportion of the population in each of the all age groups. There is not a decrease or increase in population; it is stable.
Answer:
Approximately 22,000 metric tonnes of fish per year
Explanation:
From the graph,
Rate of decline :
(metric tonnes of fish in 1965 - metric tonnes of fish in 1995) / range of years
(700,000 - 40,000)metric tonnes ÷ (1995 - 1965)
660,000 metric tonnes ÷ 30 years
660,000 / 30
= 22,000 metric tonnes per year
Approximately 22,000 metric tonnes of fish per year
