What Makes Kelp Vital in Biology and Everyday Life?
Kelps are seaweeds that fall in the genera of brown algae. It has 31 different species and can be abundantly found in the coastal areas of the colder marine ecosystems. These are big algal species that provide critical habitats for many organisms and species in the marine ecosystem. Kelp is also an excellent source of iodine and potash and is consumed as a delicacy. Here, we will study what kelp is and its benefits.
Kelp is a seaweed falling in the order Laminariales. The morphological structure of this seaweed resembles the algal species and it produces a complex carbohydrate known as algin. It grows very fast and forms a kelp forest near the coasts. It can be seen floating on the sea surface. It is named brown algae due to its characteristic colour. Its colour can vary from olive green to brown and gives a characteristic colour to the marine ecosystem.
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Due to its vast span of growth, it forms a huge forest-like structure underneath the shallow part of the sea resulting in the formation of a habitat for a diverse group of species. Invertebrates and fish flourish in this habitat as there is an ample supply of food available to support this unique ecosystem.
Structural Features of Kelp
Now that we know what is kelp, let us proceed to know its botanical features. The leaves of this species are long and flat and form tangles. It is hard to row a boat and causes hindrance for sea ferries. They are primarily found in the colder regions of the Atlantic Ocean and the Pacific Ocean.
The size of these algal species ranges from 1 to 3 meters. It might belong to the algae family but has strong stems that cling on the surface underneath the shallow portion of sea beds. The stem is strong enough and resembles that of the small plants. It is a fascinating fact that the stem of this plant is perennial whereas the meristematic portion or the growing blade parts are annual. Every year, the blades fall off whereas the stem remains submerged in the seawater.
Some of the species of sea kelp can grow as long as 65 meters. It is called giant kelp and is considered to be the largest among all the species known. It can be found in seawater where the temperature ranges from 18 to 20 °C.
The brilliant part of this plant’s morphology is that it resembles the structure of the advanced botanical species. The stem part holds to the ocean floor with its root-like attachments and the meristematic parts grow further to float on the surface. The stem-like strong lower portion enables this algal species to withstand the force of waves and other devastating external conditions and grow. The stalks also produce long branches with flat leaf-like projections. In fact, the internal tissues of the stem have helped in the transportation of organic materials to the entire body of kelp algae.
Another reason for the blades of kelp forest floating easily on the sea surface is the presence of air bladders in them. The presence of fleshy blades on the long stalks contains tissues that are filled with air. This enables the plant to float and absorb shock.
Kelp as Edible Seaweed
Kelp or brown algae are also considered a delicacy in some places. It is used to make excellent dishes and is highly nutritious too. The nutritional benefits of kelp are as follows.
Good Source of Iodine and Potassium: It contains two essential elements iodine and potassium required for our proper physiological functioning. Iodine helps us to keep our thyroid levels intact and to avoid different diseases related to the thyroid glands. Potassium keeps our neurological system functioning.
Good Source of Tyrosine: Tyrosine also enables to keep the thyroid gland properly functioning. It thus helps in cell damage repair, energy production, and growth control.
Vitamins and Minerals: It is also a good source of vitamins and minerals that our body needs for proper physiological functions.
Fiber: One of the biggest sea kelp benefits in terms of nutrition is the addition of a high amount of fiber to our diet. It helps in keeping our bowel movement better and also aids in digestion.
Economic Importance of Sea Kelp
It is used to extract alginic acid. This acid is used to make natural thickening agents in food industries. This natural thickening agent is used to manufacture bakery products and ice creams.
This acid is also used to make surgical threads and batteries.
Its natural compost is used as an excellent fertilizer for organic farming.
As it contains a high amount of potash, it is used to extract soda ash for glass industries.
Kelp for plants can be used for aquaponics and other aquarium cultures for growing fish.
As it is present in a vast amount on the sea surface, it fixes carbon and reduces the presence of this gas in the atmosphere.
Fun Facts
Kelp Minecraft: A digital presentation of kelp used for a video game named ‘Minecraft’. This game allows the players to create ocean biomes on their own using the various resources available
These are the features and benefits of kelp you should know. It can be used as a nutritional source and can serve as an exceptional kelp forest ecosystem in the seas and oceans.
FAQs on Kelp: Structure, Benefits & Applications
1. What are the main structural parts of a kelp, and what is the function of each part?
A kelp's body, or thallus, is differentiated into three main parts, each with a specific function:
- Holdfast: A root-like structure that anchors the kelp to the rocky seabed. Unlike true roots, it does not absorb nutrients.
- Stipe: A flexible, stem-like structure that extends from the holdfast, providing support and elevating the blades towards the sunlight.
- Blades (or Fronds): Leaf-like structures that are the primary sites of photosynthesis. They absorb nutrients and sunlight from the water to produce energy. Many species also have gas-filled bladders called pneumatocysts at the base of the blades to help them float.
2. Is kelp a type of plant? Explain its scientific classification.
No, kelp is not a true plant. While it resembles one, it lacks the complex vascular tissues (xylem and phloem) found in terrestrial plants. Kelp is a type of large brown algae belonging to the Kingdom Protista. Specifically, kelps are classified under the order Laminariales. This distinction is crucial as it highlights differences in structure, reproduction, and nutrient absorption compared to the members of the Plant Kingdom.
3. What are the primary benefits of kelp for human health and diet?
Kelp is a highly nutritious food source with several key health benefits. It is one of the best natural sources of iodine, which is essential for thyroid function. It is also rich in various vitamins and minerals, including:
- Vitamin K1 and Folate
- Minerals like magnesium, iron, and calcium
- Antioxidants that help combat oxidative stress
- A type of dietary fibre called alginate, which may help block fat absorption and promote gut health.
4. Beyond its use as a food source, what are some important industrial and agricultural applications of kelp?
Kelp has several significant applications. The most important is the extraction of alginate (or algin), a gelatinous substance used as a thickening and emulsifying agent in products like ice cream, toothpaste, cosmetics, and pharmaceuticals. Additionally, dried or processed kelp is used as a nutrient-rich soil conditioner or fertiliser in agriculture. Researchers are also exploring its potential as a sustainable source for producing biofuels.
5. Why are kelp forests often referred to as the 'rainforests of the sea'?
This comparison is made because kelp forests, like rainforests, are incredibly productive and biodiverse three-dimensional habitats. They play a critical ecological role by:
- Providing food and shelter for a vast number of marine species, including fish, sea urchins, and sea otters.
- Functioning as crucial nursery grounds for juvenile fish and invertebrates.
- Performing significant carbon sequestration, capturing atmospheric carbon dioxide through photosynthesis.
- Protecting coastlines from storm surges and erosion by dampening the force of waves.
6. How is the holdfast of a kelp functionally different from the roots of a terrestrial plant?
The primary difference lies in their function related to nutrient absorption. A plant's roots have two main jobs: anchoring the plant and absorbing water and nutrients from the soil through vascular tissues. In contrast, a kelp's holdfast has only one primary function: anchorage. It grips onto a rock or other hard substrate to keep the kelp in place. All nutrient absorption in kelp occurs through the blades (fronds) directly from the surrounding water.
7. What specific environmental conditions are required for large, healthy kelp forests to thrive?
Kelp forests have very specific requirements and are not found everywhere. They need a combination of the following conditions:
- Cold Water: They thrive in cool, temperate waters, typically below 20°C (68°F).
- Nutrient-Rich Water: They require areas with upwelling currents that bring nutrients like nitrogen and phosphorus from the deep ocean to the surface.
- Sunlight: Clear water is essential to allow sufficient sunlight to penetrate for photosynthesis.
- Hard Substrate: A rocky seafloor is necessary for the holdfast to attach securely. They cannot grow in sandy or muddy bottoms.
8. How does kelp reproduce, and why is its life cycle considered an example of 'alternation of generations'?
Kelp exhibits a complex life cycle known as alternation of generations, which involves two distinct life stages: a large diploid sporophyte and a microscopic haploid gametophyte. The cycle is as follows:
- The large, visible kelp is the sporophyte (2n), which produces haploid spores (n) through meiosis.
- These spores settle and grow into tiny, filamentous male and female gametophytes (n).
- The gametophytes produce gametes (sperm and eggs).
- Fertilisation occurs, forming a diploid zygote (2n), which then grows into a new, large sporophyte, completing the cycle.
This switch between multicellular haploid and diploid forms is the defining feature of alternation of generations.
