Question

Seafoam which is drifted to the seashores is formed by
A. External shell of Cuttlefish
B. Algal bloom
C. Bones of octopus
D. Calcareous matter excreted by cephalopods

Answer 1

Hint: Sea foams are produced by the natural phenomenon of the ocean that forms a white leathery substance which floats on the water surface and gets accumulated at the seashore. Sea foams are formed by photosynthetic organisms. Their overgrowth in the oceans results in blooms that give rise to the seafoam.

Complete answer:
Seafoam is also known as beach foam or algal foam. This type of foam is formed by the agitation of seawater and is drifted towards the seashore. The foam contains a high amount of organic matter that is obtained from algal blooms. Large blooms of algae decay at the seashore and they are a common source of thick sea foams. This phenomenon is not native to a certain place and it can be formed at any place in the world. Most of the sea foams are not harmful to humans and its production is an indication of the productive ecosystem. Algal blooms are caused due to excess of nutrients in the water bodies. Its excessive growth could lead to the death of other aquatic plants.

Hence, the correct answer is option B.

Note: The natural algal foam is light and airy without any unpleasant odours and sliminess. In most cases, it is white but in some cases, the colour of the foam depends upon the type of the plankton involved or the presence of tannins in the water. Sometimes foam is formed by the discharge of chemical substances and wastes in the water bodies.