Hey Steemians in today’s article I will be talking about seaweeds. In some of my old articles I was writing about sea animals adding one more chapter to that series I am writing today about seaweeds or macroalgae. Seaweeds are macroscopic plant-like which floats in the water column, some seaweeds grow upto 60 meters in length. For example kelp forest is dense seaweed forest underwater which provide food and shelter to my sea animals.
The structure of seaweeds is comprised of thallus (algal body), stipe (resembles stem), holdfast (required for attachment to surface) and haptera (these are extension of the holdfast play role in anchoring to benthic substrate) (1). The environmental conditions which favors the growth of sea weeds is very mere that is they require sea water for their growth and proper sunlight to carry out photosynthesis. For the attachment purpose they use rocky base which is present in the littoral region of the sea, they flourish more in rocky coasts then in sandy area. However there are few algae which can grow independent of substratum like Sargassum and Gracilaria (2).
The reproduction of seaweeds can take place both by asexual mode and sexual mode. Seaweed reproduces asexually by fragmentation in which if part of algae breaks off it can regenerate into whole new algae. The offsprings which are formed from asexual mode of reproduction are genetically identical to each other. In case of sexual mode of reproduction, male and female spores are produced by sporophyte and they settle after being released from sporophytes and produce gametes (sperm or egg). The gametes are either released in water or any one of them (sperm or egg) retains their gametophyte plant body and then fertilization takes place and zygotes forms which develop and grow into sporophytes and life cycle continues (3).
Seaweeds are divided into three types based on their pigments; red algae (rhodophyta), green algae (chlorophyta) and brown algae (phaeophyta).
The brown algae (phaeophyta) are having more xanthophyll pigment fucoxanthin compared to chlorophyll a and c, beta carotene. Their cell wall is made up of cellulose and alginic acid, the laminarin is major carbohydrate. The Kelps are largest brown algae with length of 70 meters. The red algae (rhodophyta) have pigments phycoerythrin and phycocyanin which gives red color to algae. The walls of red algae are made up of cellulose, agar and carrageenan and fluoridean starch is major carbohydrate reserve. The green algae (chlorophyta) have chlorophyll a and b more in proportion to other pigments. The food is stored in the form of starch (2).
Now let’s talk about uses of seaweeds, they are having a long lists of uses covering food, medicines and in research also. It is well known that seaweeds are delicacy in many countries from East Asia and South East Asia like Singapore, Thailand, Vietnam, Indonesia, Japan, Korea, China, Taiwan etc. Mainly red algae are used in foods like Porphyra, Kappaphycus and Gigartinoid. Red alga is also source of alginate, carrageenan and gelatinous products like hydrocolloids and phycocollids. They are used in food industry as food preservatives, additives in bakery and confectionary (4).
There is lots of health benefits associated with the consumption of seaweed. It has been found that seaweeds are very rich source of proteins. It has been found by scientists that red algae Palmaria palmata is source of amino acids like leucine, valine and methionine and Porphyra amino acids profile has been reported to be similar to leguminous plants like peas and beans. Other than nutritional benefits researchers have found that Porphyra is source of renin inhibiting peptide which plays role in lowering blood pressure (5).
The brown algae have also health benefits in an experiment carried out by researchers from Japan. They have shown that consumption of brown algae can help in reduction weight by inhibiting the accumulation of fats. They have proposed that brown algae contain fucoxanthin which helps in reduction of fat accumulation. The compound Fucoxanthin stimulates UCP1 protein (uncoupling protein) which plays role in fat oxidation; this protein is found white adipose tissue which is mainly present in the abdominal region of the body. So with this study on obese rats they found that brown algae help in weight loss. Another role of fucoxanthin is increased production of DHA (omega-3 fatty acids), which reduces the chances if accumulation low density lipoprotein which plays a great deal in obesity (6).
Seaweed growing on a rock, Atlantic Ocean.
Another use of seaweeds is in wound healing. Alginates which are derived from seaweed are used in wound dressing to keep the wound moist. A group of researcher from Newcastle University has used alginate for preservation of stem cells at hypothermic conditions by encapsulating it in the calcium alginate to maintain its viability. In this study they found that alginate encapsulation helps in maintaining 70% viability of stem cells at room temperature (7).
The seaweeds are also used in cosmetics. The ultraviolet rays are reason for mutation due to molecular and genetic changes so to protect human from UV rays scientists from King’s College London have extracted a compound from seaweed and checked its activity as UV protectant. They have extracted mycosporine-like amino acids (MAA) also called as palythine, a compound which is frequently found in marine animals which are living in sunlight rich and shallow water. They used this compound on human cell line to study its activity against UV rays and in addition to this they also produce anti-oxidant compounds which protect the skin from oxidative stress (8).
In addition to use in food and research, seaweeds can be used in biofuel production. With increasing population and development around the globe the need for energy sources is also increasing, and they are quite lacking to fulfill the needs. So there is need of using natural and renewable sources for production fuel to meet the demands. For this seaweeds can be used because of their capacity to produce energy-rich oils. The reasons which make them a good candidate for production of fuel is that high growth rate, high lipid content and they contribute to almost 40% of carbon fixation (9).
Seaweed farming in Indonesia in small rectangular area, divided within families.
The International Energy Agency expects that biofuels will contribute 6% of total fuel use by 2030
On more interesting use of seaweed is in making superconductors. This is being carried out in China to make lithium-ion batteries and fuel cell from seaweed based material. Alginate from seaweed is known for its chelating property, by using this property they bound the metal with alginate to make egg box like structure. This material they tested against conventional graphite based and showed that it produced around 372 mAhg-1 more capacity than graphite based, which can be used to double the range of electric cars (10).
So in the end I would like to say the seaweed are full of uses to humankind. They cover a whole range of needs of us like right from food to energy sources.
Conclusion
Seaweed, a plant-like algae, as the name suggest plant like, they need proper sunlight for photosynthesis. They find a substratum in sea by attaching to rocks for growth and reproduces asexually in fragmentation. Three catagorized seaweeds are based on the pigment they produce which produces different color in appearance. Seaweeds have a huge range of application from food to medication and that's the reason its been cultivated in several parts of the world. As the amount of production is very high and is very cost effective researchers have found a way to produce energy from it.
Here's a short video on harvesting a seaweed for the purpose of food
Harvesting a French coastal superfood.
References
The Seaweed Site: information on marine algae
Seaweed: An alternative protein source.
Brown Seaweed Contains Promising Fat Fighter, Weight Reducer.
Seaweed: From superfood to superconductor.
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It's really amazing how something that is often discarded - as not useful - such as seaweeds, turns out to pack a whole bunch of amazing health benefits. I personally haven't tried seaweeds out. But this post is certainly a good motivator @vinamra. Thanks for sharing, buddy.
Thanks @rickie
Well, I also haven't tried it yet but yeah the benefits are certain.
wow I wasn't aware of all the different benefits that seaweeds could offer.
Really informative and with tons of information. Kudos!
Thanks @dedicatedguys
Yeah they really are that much beneficial I'm glad you like it. 😊
The seaweeds are very important part of the eco system. What they do is quite amazing.
Thanks for the education.
Thanks for the comment @adetola I'm glad you find it educative.
Cheers
You are welcome.
This post has been rewarded with 100% upvote from @indiaunited bot.
excellent writeup. This is very informative.
I wonder why in India sea weed cultivation is not popular. It seems its one of the rare agriculture forms where vertical farming is possible