Accounting of ecosystem services from microalgae in wetlands of Shivamogga district, KarnatakaCite
Asulabha K. S.1,4, Jaishanker R.4, Sincy V.1,4 and Ramachandra T. V.1,2,3
1Energy & Wetlands Research Group [CES TE15], Centre for Ecological Sciences,
2Centre for Sustainable Technologies (ASTRA)
3Centre for infrastructure, Sustainable Transportation and Urban Planning (CiSTUP)
Indian Institute of Science, Bangalore - 560 012, India.
4Indian Institute of Information Technology and Management-Kerala (IIITM-K), Thiruvananthapuram, Kerala
envis.ces@iisc.ac.in
tvr@iisc.ac.in Phone:
080 22933099/22933503 (extn 107, 114)
Results and Discussion
Ecosystem services provided by microalgae
Microalgae have the potential to transform 9-10% of solar energy into biomass with a theoretical lipid yield of about 280 ton/ha/year (Khan et al., 2018). Microalgae-based biofuels are advantageous because of (a) the rapid growth rate of microalgae, (b) high lipid content (more than 50% by cell dry weight), (c) requiring less land, (d) high carbon dioxide absorption and uptake rate, (e) potential for wastewater treatment (phycoremediation), and (f) producing various value-added by-products (Chamkalani et al., 2020; Yang et al., 2011). The production cost of microalgae oil varied between $0.883 and $2.088 per litre (Ansari et al., 2018). Carbohydrates and proteins derived from microalgae had a value of $14.25/kg and $82/kg respectively (Ali et al., 2017). Chlorella spp. and Spirulina spp. are used as dietary supplements as they provide vitamins, proteins, polysaccharides, and lipids (Araujo et al., 2021). The average cost of biodiesel in India is Rs. 52.7 per litre (Mathew et al., 2021). Microalgae are the primary producers, providing food for other organisms at various trophic levels. A symbiotic association occurs between Azolla sp. (macrophyte) and Anabaena sp. (microalgae) that can fix atmospheric nitrogen (Slembrouck et al., 2018). Thus, microalgae provide several environmental and economic benefits. The list of microalgae found in the wetlands of Shivamogga district is shown in table 2.
Table 2: Microalgae in wetlands of Shivamogga district, Karnataka
Family | Species |
Chlorophyceae | Ankistrodesmus spiralis, Arthrodesmus sp., Coelastrum microporum, Coelastrum reticulatum, Crucigenia retangularis, Dimorphococcus lunatus, Eudorina lelgans, Kirshikoviella limnetica, Oocystis gigas, Pediastrum simplex, Pediastrum tetras, Scenedesmus dimorphos, Scenedesmus quadricauda, Selanastrum abundance, Selanastrum acuminatus, Tetraedon longispinum, Tetraedon caudatum, Ankistrodesmus sp., Cosmarium sp., Desmidium swartzii, Eustrum sinuosum, Mougeotia sp., Oedogonium sp., Pediastrum sp., Pleurotaenium repandum, Scenedesmus acutiformus, Scenedesmus acutus, Spirogyra sp., Staurastrum leptocladum, Staurastrum pyramidatum, Zygnema sp., Actinastrum sp., Coelastrum sp., Chlamydomonas sp, Eudorina sp., Chlorella sp., Selenastrum sp., Tetradron sp. |
Cyanophyceae | Anacystis sp., Anabaena aphnizimenoides, Agmenellum sp., Arthospora sp., Gloecapsa sp., Merismopedia aeruginosa, Merismopedia glauca, Merismopedia tenuissima, Microcystis aeroginosa, Nostoc microscopium, Oscillatoria formosa, Phormidium sp., Rivuleria sp., Synechocystis sp., Anabaena sp., Chroococcus sp., Lyngbya sp., Merismopedia punctate, Oscillatoria curviceps, Oscillatoria subsalsa, Raphidiopsis sp., Spirulina platensis |
Bacillariophyceae | Anomoeonies sphaeophora, Colonies pulchra, Cymbella tumida, Cymbella affinis, Diatoma vulgare, Fragillaria intermedia, Gomphonema abbreviatum, Gomphonema lanceolatum, Gyrosigma elongata, Melosira granulata, Navicula pupula, Navicula pigmea, Navicula radiosa, Nitzschia amphibia, Pinnularia major, Pinnularia microstauron, Surirella capronii, Synedra ulna, Cocconies placentula, Cyclotella kuezingiana, Cymbella lanceolata, Cymbella turgidula, Gomphonema constrictum, Navicula gracilis, Navicula reinhardtii, Fragilaria construens, Pinnularia nobilis, Tabellaria flocculosa, Synedra tabulate, Cymbella stuxbergii, Cymbella subtinii, Cymbella ventricosa, Gyrosigma attanuatum, Gyrosigma fasciola, Hantzschia sp., Navicula cuspida, Navicula greagria, Nitzschia acicularis, Nitzschia recta, Nitzschia vermicularis, Pinnularia gibba, Pinnularia strptoraphae, Synedra capitate, Achnanthes sp., Melosira sp. |
Euglenophyceae | Euglena acus, Euglena gracile, Euglena elongata, Euglena oxyalis, Phacus longicauda, Phacus pleuronectes, Phacus menson, Strombomonas gibberosa, Trachelomonas robasta, Phacus acunitus, Phacus acutus, Phacus brevicaudatus, Phacus lismorensis, Trachelomonas hispida, Trachelomonas oblonga, Trachelomonas olvicina, Euglena oxyuris |
Source: Parisara et al., 2016; Sayeswara et al., 2011; Rashmi et al., 2013; Begum et al., 2016 | |
During biodiesel production from microalgae, 10% of crude glycerol is formed, which can be further used for the production of hydrogen, ethanol, biopolymers, and fuel additives through the gasification and pyrolysis processes (Bosnjakovic and Sinaga, 2020). The cost of algal biodiesel production ranges from 0.42 to 7.50 USD/L in open ponds and 1.25 to 72 USD/L in closed PBRs (Louw et al., 2013). A biodiesel cost of $9.73 USD per litre was incurred during the conversion of 1 kg of dry algae into 11.4 MJ of biodiesel energy (Ansari et al., 2020). The final cost of biodiesel ranged from $0.42-0.97/L (Nagarajan et al., 2013). Proteins and carbohydrates from microalgae can be converted into animal feed, dietary or nutritional supplements, and biofertilizers, while carbohydrates and lipids are converted into diverse forms of biofuels (Chowdhury and Loganathan, 2019). Biofuels from microalgae include biodiesel, bioethanol, biohydrogen, biogas, etc. (Mizik and Gyarmati, 2021).
Microalgae in wetlands provide various provisioning, regulating, and cultural services. The value of provisioning services (considering the values of food, fuel, by-products, medicinal, ornamental, and genetic material) provided by microalgae in the wetlands of Shivamogga district is 1446 million Rs/year. The value of regulating services (considering nutrient recycling, water purification, carbon sequestration, and nursery service) provided by microalgae in the wetlands of Shivamogga district is 3576 million Rs/year. The value of cultural services (considering values for spiritual, recreational, educational, cultural and species appreciation) provided by microalgae in the wetlands of Shivamogga district is 575 million Rs/year (figures 2, and 3).
Figure 2: Ecosystem services from microalgae of Shivamogga district (grid wise)
Figure 3: Ecosystem services from microalgae
The total ecosystem supply value (TESV) is the aggregation of all the 3 ecosystem services:
TESV = Provisioning services + regulating services + cultural services
Figure 4: TESV from microalgae
The total ecosystem supply value (TESV), which is the sum of provisioning, regulating, and cultural services provided by microalgae in wetlands (figure 4), of Shivamogga district accounted to 5597 million rupees per year or 429519 Rs/ha/yr (table 3). The net present value (NPV) based on the annual flow of 5597 million rupees amounted to 144 billion rupees (figure 5). This emphasizes the economic significance of wetlands and ensure proper management and conservation of wetlands to sustain ecosystem services that benefits the livelihood of people,
Figure 5: TESV from wetlands (from microalgae) and NPV of wetland assets
Table 3: Total economic value from microalgae in wetlands of Shivamogga district
Services | Details | Value |
Wetland: Total area (ha) based on grid | 13030.66 | |
Provisioning Service | Total Rs/yr (in Million Rupees) | 1446 |
Production Rs/ha/yr | 110943 | |
% distribution | 26 | |
Regulating Service | Total Rs/yr (in Million Rupees) | 3576 |
Production Rs/ha/yr | 274454 | |
% distribution | 64 | |
Cultural Service | Total Rs/yr (in Million Rupees) | 575 |
Production Rs/ha/yr | 44122 | |
% distribution | 10 | |
TESV | Total Rs/yr (in Million Rupees) | 5597 |
Production Rs/ha/yr | 429519 | |
NPV | NPV in Billion Rupees | 144 |