Seaweeds

About

●Seaweed, or macroalgae, refers to thousands of species of macroscopic, multicellular, marine algae.

●The term includes some types of Rhodophyta (red), Phaeophyta (brown) and Chlorophyta (green) macroalgae.

Size

●Their size varies from microscopic species to large underwater forests.

Environmental requirements

Two environmental requirements dominate seaweed ecology.

1. Seawater (or at least brackish water) and light sufficient to support photosynthesis.
2. An attachment point.

Therefore seaweed most commonly inhabits the littoral zone(nearshore waters) and within that zone, on rocky shores more than on sand or shingle.

Uses

●Food: Seaweed is edible and can be used in sushi, salads, and dried snacks. It's a good source of vitamins, minerals, proteins, lipids, and polysaccharides.

●Fertiliser: Seaweed can be used as a fertiliser, and it helps improve water quality by reducing the amount of nitrogen and phosphorus that drains into rivers and oceans.

●Medicine: Seaweed has been used in traditional medicine to treat coughs, asthma, haemorrhoids, nosebleeds, boils, goitre, scrofula, stomach ailments, and urinary issues.

●Cosmetics: Seaweed can be used to make cosmetics.

●Biofuels: Seaweed can be used to make ethanol or biodiesel.

●Wastewater treatment: Seaweed can be used to reduce nitrogen and phosphorus compounds in wastewater.

●Animal feed: Seaweed can be used as feed for animals and fish.

Significance

●Seaweed species such as kelps provide essential nursery habitat for fisheries and other marine species and thus protect food sources; other species, such as planktonic algae, play a vital role in capturing carbon and producing at least 50% of Earth's oxygen.

PRACTICE QUESTION

Q.Consider the following statements regarding the “Seaweeds”:

1. Seaweeds are marine fungi species found in various oceans.
2. They most commonly occur in the deep water in oceans.
3. They provide essential nursery habitat for and other marine species

How many of the above statements is/are correct?

A. Only one

B. Only two

C. All Three

D. None

Answer: A

Explanation:

Statement 1 is incorrect:

●Seaweed, or macroalgae, refers to thousands of species of macroscopic, multicellular, marine algae. ( They are not fungi but algae species)

●The term includes some types of Rhodophyta (red), Phaeophyta (brown) and Chlorophyta (green) macroalgae.

Statement 2 is incorrect:

●Seaweed most commonly inhabits the littoral zone(nearshore waters) and within that zone, on rocky shores more than on sand or shingle.

Statement 3 is correct:

●Seaweed species such as kelps provide essential nursery habitat for fisheries and other marine species and thus protect food sources.