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Green Algae

Algae are a group of aquatic organisms capable of photosynthesizing. For most people, some algae are familiar; for example, seaweeds (phytoplankton or kelp), lake algal blooms or pond scum. There is, moreover, a vast and varied algae universe that is not only useful to us but vital to our life.

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The term “algae” encompasses numerous organisms able to produce oxygen via photosynthesis (generation of carbohydrates by extracting light energy from the sun). We are not even closely related to these species. Nevertheless, they are joined by certain traits, thus separating them from the other larger group of photosynthetic entities: ground plants. Algae lack real leaves, roots, and stems, and a vascular system for the flow of nutrients and water throughout the body. According to an article issued in 2014 in the journal Current Biology, most algae are unicellular. These often take place in a variety of shapes and sizes. They may exist as microscopic cells and single, they may be multicellular and macroscopic; they may inhabit colonies; or they may have a leafy appearance, as with seaweeds like giant kelp. Picoplankton may vary from 0.2 to 2 micrometres, while giant kelp fronds are as wide as 60 meters in size. Lastly, in ranging habitats, algae are found, both in freshwater and saltwater.

As a result of these features, prokaryotic entities — cyanobacteria (also known as blue-green algae) and eukaryotic organisms (all other algal species) are generalised as “algae.” Because ” algae ” do not constitute a natural unit that has descended from a common ancestor, like cyanobacteria, is popular in the informal” algae “community,” said Linda Graham, a botany professor. The word ‘eukaryotic algae ‘ includes cyanobacteria. It may also interest you to note that species of cyanobacteria are related to chloroplasts, that in the land plants it is the source for photosynthesis. According to the University of California Museum of Paleontology, these early cyanobacteria were swallowed up by primitive plant cells sometimes in the early Cambrian period or late Proterozoic period.

Archaea and Bacteria are among the prokaryotes. Without an ordered cell structure, they are simpler species and the associated DNA easily floats inside the cytoplasm as a twisted mess. Diversly, all other living organisms are eukaryotes: protists, insects, fungi. There’s more cohesion in their bodies. We include mechanisms called organs for conducting a variety of cellular roles and their DNA centrally located in a compartment known as the nucleus.

Most algae are present in aquatic localities. Within saltwater seas or in freshwater lakes, these species can survive. They can also experience a variety of temperatures, concentrations of oxygen or carbon dioxide, turbidity and acidity. Algae mostly independently live in their different forms of growth, but they can also form symbiotic relationships with many non-photosynthetic entities like ciliates, sponges, molluscs and fungi.

Examples of Green Algae


Marimo is an unusual growth type of Aegagropila linnaei with a velvety appearance in which the algae develop into large green balls. The species can be found in Japan and Northern Europe in a number of lakes and rivers. In Japan and Iceland, marimo ball colonies are known to form, but their population is at the verge of extinction.

Order: Cladophorales

Class: Ulvophyceae

Phylum: Chlorophyta

Scientific name: Aegagropila linnaei

Family: Pithophoraceae

Sea lettuce

Ulva lactuca is an edible green alga in the Ulvaceae family, also known as sea lettuce. It’s the Ulva genus type species.

Scientific name: Ulva lactuca

Phylum: Chlorophyta

Class: Ulvophyceae

Order: Ulvales

Family: Ulvaceae

Rank: Species

Ulva intestinalis

In the Ulvaceae family, Ulva intestinalis is a green alga known as gutweed, sea lettuce, and grass kelp. The tubular members of the sea lettuce genus Ulva were grouped in the genus Enteromorpha until they were reclassified by genetic work completed in the early 2000s.

Scientific name: Ulva intestinalis

Rank: Species

Higher classification: Sea lettuce

Phylum: Chlorophyta

Family: Ulvaceae

Order: Ulvales

Haematococcus pluvialis

Haematococcus pluvialis is a Chlorophyta freshwater species from the Haematococcaceae family. This species is well known for its high content of the important antioxidant astaxanthin in aquaculture and cosmetics.

Scientific name: Haematococcus pluvialis

Phylum: Chlorophyta

Higher classification: Haematococcus

Order: Chlamydomonadales

Rank: Species

Family: Haematococcaceae

Dead man’s fingers

Codium fragile is commonly referred to as Dead Man Fingers, Green Sea Fingers, Forked Felt-Alga, Felty Fingers, Stag Seaweed, Green Sponge, Sponge Seaweed, Green Fleece, and Oyster Thief, is a seaweed genus in the Codiaceae family.

Phylum: Chlorophyta

Scientific name: Codium fragile

Rank: Species

Higher classification: Codium

Class: Ulvophyceae

Order: Bryopsidales


Chlorella is a genus belonging to the Chlorophyta group of single-celled green algae. It is triangular in shape, with a diameter of about 2 to 10 μm, and without flagella. This incorporates the chlorophyll-a and -b green photosynthetic pigments in its chloroplast.

Scientific name: Chlorella

Rank: Genus

Class: Trebouxiophyceae

Phylum: Chlorophyta

Order: Chlorellales

Higher classification: Chlorellaceae

Water silk

Spirogyra is a Zygnematales filamentous chlorophyte green algae, named for the chloroplastic helical or spiral structure characteristic of the species. It is commonly found in freshwater habitats, and over 400 species of spirogyra are found in the world.

Kingdom: Plantae

Class: Zygnematophyceae

Scientific name: Spirogyra

Division: Charophyta

Order: Zygnematales

Rank: Genus

Green Algae Bloom

An algal bloom or algae bloom is a prompt increase of aggregation in the algal population of freshwater or coastal water systems and is usually identified by water discolouration of their pigments. The term algae include most types of aquatic photosynthetic entities, including multicellular, macroscopic organisms such as marine algae and unicellular microscopic entities such as cyanobacteria. Algal bloom generally refers to unicellular, microscopic algae, not macroscopic algae, growing rapidly. A kelp forest is one example of a macroscopic algal bloom.

The term ‘ algal bloom’ is explained incoherently based on the science stream and can range from a’ mini bloom’ of harmless algae to a large, harmful bloom event. As ‘algae’ is a widespread term that includes entities of differing growth rates, sizes, and nutrient requirements, there is no threshold level recognized officially for what is described as a bloom. As there is no scientific accord, blooms can be quantified and distinguished in many ways: new algal biomass measurements, photosynthetic pigment concentration, negative effect bloom-quantification, or relative algae concentration in connection to the rest of the microbial community.

Algal blooms are the result of a nutrient from fertilizer runoff, such as nitrogen or phosphorus, entering the water environment and causing excessive algae growth. An algal bloom affects the entire ecosystem; it can have beneficial results, such as simply feeding higher tropical levels to more harmful effects, such as blocking sunlight from reaching other organisms, causing oxygen depletion in the water, and secreting toxins into the water depending on the organism. Eutrophication is the process of over-supplying nutrients leading to algal growth and oxygen depletion. Blooms that can damage animals or the environment are referred to as “harmful algal blooms” (HAB) and can lead to the death of fish.

HABs have been noted to cause unfavourable effects to a wide range of aquatic entities, most notably marine mammals, seabirds, sea turtles, and finfish. The effects of HAB poisons on these gatherings can incorporate hurtful changes to their formative, neurological, immunological, or regenerative limits. The most obvious impacts of HABs on marine natural life are huge scale mortality occasions associated with poison creating blooms.

Algal blooms produce toxins that reduce the human consumption suitability of water. Their large occupation on water and their series that spread easily lead to rapid water contamination, posing a health hazard for humans. When such polluted water comes into contact with human skin, strong irritation, itching and even skin diseases are also experienced.

The emergence of significant algal blooms will contribute to marine life’s major deaths. As a result, a dead zone of dead animals and plant life will be the area around the algal blooms. The resultant foul smell will affect the rest of the aquatic life, driving it away from the area more. Furthermore, as the growth of algal blooms causes the death of aquatic life, large-scale losses can occur to fishermen who rely on fishing as an activity generating income.

Many businesses need only purified water from resources of water to power their development, such as food processing firms. It ensures that additional water treatment costs would emerge from the occurrence of algal blooms to receive clean water resulting in risen overhead costs.

Fertilizers must be used by farmers by supplying them with insufficient nutrients to raise crop yields. Nonetheless, by using methods such as top dressing or rubbing based on the nutrients to be provided, this can be achieved optimally. Farmers are advised to consult on the mode and quantity of fertilizer to be used by agricultural experts.

Disinfection and tertiary processing to eliminate elements such as phosphorus and nitrogen by processes such as nitrification and subsequent sludge disposal is compulsory to avoid feeding of unnecessary nutrients from large sources of water as in rivers, ponds, oceans and streams.

The drug has been used to combat algal blooms successfully. In smaller water sources such as large wetlands or small lakes, this is ideal in simple control of the effect of the substance as well as aquatic life.

Ultrasound treatment equipment utilizes ultrasonic sound waves in water bodies to search for algal blooms and if found to monitor their growth, reducing the growth of algae by up to 90%.

To accomplish the minimal pollution goals of global environmental conservation, it must begin with oneself. Individual interests/initiatives by minimizing waste, recycling and reuse to save the environment. When practised at home, at school/work; it can serve to reduce the total nutrient load in water resources and even facilitate the process of water treatment.

Questions and Answers:

Q1) Give two examples of green algae?

Ans: Chlorella and Ulva intestinalis

Q2) Algae Bloom leads to_______?

Ans: Eutrophication

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