Blue-Green Algae

• Blue-green algae often referred to as Cyanobacteria, are a definite group of photosynthetic bacteria that generally grows up in diversity of habitat, freshwater  such as ponds, and lakes, and marine water ocean. They can also grow in adverse habitats such as in hot water springs. Example - Oscillatoria.

• These bacterias are mainly blue-green, but they can also be found in green, reddish-purple, or brown colors.   

• The blue-green algae can grow expeditiously with accurate environmental conditions. These are mainly buoyant and form floating mats on the surface of the water. This is known as the “blue-green algae bloom.” Their blooming period is mainly between mid-June and late September, but in sparse cases, it has bloomed in the winter season. 

• Some diversified species of blue-green algae are Anabaena sp., Microcystis sp., Aphanizomenon sp., and Planktothrix sp. 

How Do They Differ from The True Algae?

• Blue-green algae cover a specific portion of the water body like true algae, but they are not eaten by the organisms. Unlike true algae, they are not a vital part of the food chain. 

• These are denoted as “primary producers” as they can convert inorganic chemicals and sunlight into usable energy for subsistent organisms. 

• Most algae are the high energy providers to larger organisms like zooplankton, and they can be found under the microscope. Zooplanktons are thereby eaten by the small fish, which in return, are eaten by the larger fish. Both small and larger fishes are eaten by raptors and mammals. 

• These true algae often bloom at the timing of blue-green algae and are mistakenly considered blue-green algae.

What Are The Concerns Associated with the Blue-Green Algae?

The leading concerns associated with blue-green algae include toxin productions, curtailed light infiltration, taste and malodor issues, discolored water, dissolved oxygen depletion during die-off, etc. 

• When these algae grow in sufficient bloom density, then they can significantly curtail the light penetration into the water, which causes adverse effects on the aquatic organisms directly and indirectly. 

• It is not recommended not to drink raw water as they grow on the surface of the water and change the composition of water and make it tasteless. 

• Some cynobacteria can change the odor and taste of water by producing cynotoxin. 

• Cynotoxin such as Geosmin is produced by various cyanobacteria like Oscillatoria, Anabaena which affects the taste and odor of water. 

• In algal bloom, many cyanobacteria produce toxins that can cause damage to nervos system, liver and gastrointestinal tract. For example, Microcystis is a number one global offender which produces toxin microcystins. Microcystins is a heptotoxin which causes damage in liver of individuals. Other toxin-producing genera include Anabaena,  Nodularia, Nostoc and Oscillatoria.

• When blue-green algae die, their cells sink, and microbes break down their cell. This process of breakdown needs oxygen and may create biological oxygen demand. The enhancement of biological oxygen demand (BOD) significantly results in the curtailment of oxygen concentration in the water, which may cause a pernicious effect on aquatic life.

What can be done to decrease the Frequency and Intensity of Blue-Green Algae Blooms?  

There are no significant prompt remedies to decrease the frequency of blue-green algae once they appear in a pond. Curtailing the number of nutrients that have been used to clean our ponds will eventually decrease the intensity of blue-green algae. But this is not a quick process as it requires the involvement of the community to fruitfully change the concentration of nutrients in a water body. This is because there could be some amount of nutrients present at the bottom, which may facile the blooming process of blue-green algae. 

However, you can help by diminishing the nutrient concentrations by uplifting the following practices in your community:

• Lawn fertilizers should only be used when required.

• Prevent yard relics from washing into storm drains.

• Always support a local provision that needs silt curtains for commercial and residential construction.

• Make sure to plant and sustain vegetative buffer strips along with the shorelines of ponds. 

 Advantages of Blue-Green Algae

• Blue-green algae are a rich source of protein and their protein is the optimum source of the essential amino acids.

• 100 grams of blue-green algae contains 2grams of carbohydrate and no fat. It is generally a low-calorie food.

• It also provides numerous amounts of vital minerals, such as calcium, magnesium, iron, potassium, and vitamin-A, C, E, B-6, etc.

• It can significantly boost-up your immune system and protect us from fatal viruses. 

• Consuming a proper amount of blue-green algae can enhance your tolerance to exercise and also alleviate fatigue. 

• They have many beneficial functions such as nitrogen fixation and cycling of nutrients in the food chain.

Conclusion

Blue green algae have both advantages and disadvantages. We play major role in providing the favourable environment for their growth which needs to be inhibited because some of their species also causes algal bloom, water pollution and produces harmful chemical. These chemical affects both animals as well as humans.