Inaugural Lecture Delivered at the University of Benin
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“THEY BOP, THEY SINK: NATURE’S ENERGY CHARGER AND AQUATIC ENVIRONMENTAL PURIFIER” “THEY BOP, THEY SINK: NATURE’S ENERGY CHARGER AND AQUATIC ENVIRONMENTAL PURIFIER” An Inaugural Lecture Delivered at the University of Benin On Thursday, 15th April 2010 By Professor (Mrs) Medina Omo Kadiri B.Sc(Hons) Botany (University of Lagos); Ph.D Limnology & Algology (University of Benin) CBiol, MI Biol (London), MNES Professor of Limnology & Algology DEDICATION This inaugural lecture is dedicated to: My mother who though saw no four walls of a school sent me to school My father who gave me love and care My husband for his wonderful support, understanding and encouragement and My children, for giving me the inestimable joy of motherhood. My siblings for the strong bond of love. i TABLE OF CONTENT DEDICATION .............................................................................................................i TABLE OF CONTENT ................................................................................................ ii SYNOPSIS ............................................................................................................... iv INTRODUCTION...................................................................................................... 1 They Bop, They Sink, What are They? ................................................................. 1 Classification ....................................................................................................... 2 Sea weeds........................................................................................................... 2 How Do Algae Bop & Sink? ................................................................................. 3 ECONOMIC IMPORTANCE OF ALGAE .................................................................. 4 Harmful Algae/Algal Bloom or “Red tide” ..........................................................18 HISTORY OF PHYCOLOGY IN NIGERIA.................................................................21 The Nigerian Phycologist: An Endangered Species.............................................21 My Phycological Foray .......................................................................................21 MY CONTRIBUTION: ..........................................................................................22 1) Taxonomy/Ecology/Biogeography of Algae .................................................22 Desmids .............................................................................................................22 Diatoms .............................................................................................................25 Euglenoids .........................................................................................................28 Chrysophytes .....................................................................................................28 2) Environmental Assessment (Water quality studies –Limnology) ..................31 3) Ikogosi Springs ............................................................................................32 4) English Lakes District, England. ....................................................................35 5) Algal Composition/Community structure & Pollution Studies .....................38 6) River Niger ..................................................................................................40 7) Niger Delta Studies ......................................................................................42 8) My Atlantic Ocean Phycological Voyage ......................................................44 9) Algal Biomass ...............................................................................................45 10) Harmful Algal Survey ................................................................................49 11) APPLIED PHYCOLOGY ................................................................................49 Bioassessment (Bioassay) ...............................................................................49 Industrial Effluents .........................................................................................50 Bioremediation studies (Phycoremediation) ..................................................54 Crude Oil /petroleum hydrocarbon Studies....................................................56 Aromatic Hydrocarbon WSF Studies...............................................................56 Studies with Refined Petroleum Hydrocarbons ..............................................58 12) A New Technique ......................................................................................61 Breakthroughs ...................................................................................................63 CHALLENGES ......................................................................................................66 ii RECOMMENDATIONS ........................................................................................66 CONCLUSION .....................................................................................................68 ACKNOWLEDGEMENTS .........................................................................................69 REFERENCES .........................................................................................................72 iii SYNOPSIS Algae [derived from seaweed “alga” (Latin) and “phykos” (Greek)] are photosynthetic organisms possessing chlorophylls and simple reproductive structures but lacking true root, stems and leaves. They occur in different habitats including extreme ones. Apart from seaweeds, most algae are extremely small culminating in millions of cells in a small volume of water. Ten divisions of algae namely Bacillariophyta (diatoms), Cyanophyta or Cyanobacteria (blue-green algae), Chlorophyta (green algae), Euglenophyta (euglenoids), Chrysophyta (golden-brown algae), Phaeophyta (brown algae), Rhodophyta (red algae), Pyrrhophyta (fire algae, dinoflagellates), Xanthophyta (yellow-green algae) and Cryptophyta (cryptomonads) are commonly recognized. Algae exhibit different kinds of movements that mimic a dance. Such movements include sliding, gliding, rotation, spinning, gyrating, summersaulting, oscillating, wriggling and flexing of body. Algae, when alive, float on water especially in the euphotic or lit zone, and sink to the bottom of a water body when they die or thrown out of the euphotic zone as a result of turbulence. The lecture gives a vivid account of the importance of algae, stressing the market or commercial values of products from algae which are multimillion dollar industries in the world. They help in the purification of the aquatic environment via processes such as bioremediation (pollution control), carbondioxide sequestration or removal and wastewater treatment. In addition they have been employed in land reclamation, reforestation, food security, renewable energy, biofuel, medicines, pharmaceutical industries, bioproducts (bioplastics), food, food supplements, fodder, aquaculture feed. They have also been used as biochemicals, global warming antidote, industrial products-phycocolloids (alginates, agar, carrageenan, minerals etc), agriculture (biofertilizer), nanotechnology, environmental studies, cosmetics, nutraceuticals etc.; hence algae can be referred as the HOPE of the PRESENT and FUTURE. The study of algae (Phycology) in Nigeria started in 1932 and there are still few Phycologists in the country to date. My researches span classical or fundamental Phycology as well as Applied Phycology. The classical aspect dealt with the taxonomy of certain groups of algae such as diatoms, desmids, euglenoids and chrysophytes among others, indicating their ecological/or biogeographical occurrences, as well as their use as indicators of environmental quality (in environmental monitoring). In Applied Phycology, my research addressed the use of algae in bioremediation- iv clean-up of pollutants such as industrial effluents, heavy metals etc. Studies with hydrocarbons (from different sources such as aromatics, petroleum, crude oil and refined petroleum products) revealed growth stimulation at low concentrations (0-50%) and inhibition at higher concentrations, the threshold being 50%. Environmental assessments of some water bodies in Edo State revealed that some water bodies, especially in Akoko-Edo were hard waters and dominated by euglenoids or blue-green algae, while others were soft water, comprising predominantly green algae and diatoms. A study on the use of algae in Long-term monitoring of English Lakes District using algae showed that some lakes remained constant in their nutrient levels, while some have changed for the better (from higher level to lower level) or worse (from lower to higher levels). The lecture also lists some harmful algae in Nigerian coastal waters of Nigeria and some freshwater environments. Niger Delta studies showed the influence of salinity on the distribution of algae on the one hand, and the preponderance of diatoms on the order, epitomizing the brackish nature of the environment. The study of the only warm and unique spring (Ikogosi Warm & Cold) in Southern Nigeria showed that both springs differed markedly physically, chemically and phycologically. Algal biomass production studied in both the natural environment and the laboratory showed that whereas algal production in the natural environment was enhanced in the dry season, laboratory investigations revealed that organic fertilizer, in particular, poultry dung, supported the greatest biomass.