The longest species of seaweed is the giant kelp Macrocystis pyrifera. It is found near the Californian shore and in different parts of the world near the Pacific Ocean. The longest specimen that has been verified is 60 metres long but unofficial reports say that even longer specimens have been found.
They form large and dense kelp forests, which become habitats for a number of different marine species. They are often located in cold and clear waters, where they resemble tall grass although they are not part of the grass family. It is a type of brown alga and belongs to the large kingdom of Protista. Since kelp is not a plant, it does not have roots and obtains its nutrients from a structure called a holdfast by which it attaches itself to the rocky bottom of the ocean. But kelp are similar to plants by the fact that they use photosynthesis to harvest the Sun’s energy and do not feed on other organisms to keep themselves alive. They are also one of the fastest growing species and are known to grow up to 60 centimetres in a single day when given perfect conditions. Strikingly, when the kelp reaches the sea surface, it grows horizontally and floats as large mats that shade the water column and the sea floor below it.
The kelps also become a source of nutrition once they decompose in the sea bed. Sea otters even use these giant kelps to avoid being floated away while they sleep.
Picture Credit : Google
