International Sakharov Environmental University Anastasiya Abramenkova Minsk 2011 Page 1
INTRODUCTION Algae are an ideal group to study responses to different environmental factors free from complications inherent in research with more complex higher plants. One of the advantages of environmental study using algae is the possibility to achieve and observe many generations during relative short time period. Page 2
Algae as Bioindicators Previous studies proved high sensitivity of the most algae towards changing of environmental conditions, especially as consequences of water pollution. Algae respond rapidly and predictably to a wide range of pollutants and provide potentially useful early warning signals of deteriorating conditions and possible causes. Page 3
Algae as Bioindicators Because of their nutritional needs and their position at the base of aquatic food webs, algal indicators provide relatively unique information concerning ecosystem conditions compared with commonly used animal indicators. Page 4
Algae as Bioindicators In most cases ecologically relevant signals of ecosystem changes are being provided that can be used to distinguish acceptable from unacceptable environmental conditions. Algal indicators are also a cost-effective monitoring tool as well. Page 5
Algae Benefits: o. Base of the aquatic food chain o. Useful indicators of pollution o. Help remove excess nutrients o. Produce oxygen o. Constitute the raw material to make agar, iodine and various food products o. Provide spawning habitat for fish Page 6
Algae Major Algal Groups ü Cyanobacteria - “blue greens” üChlorophyta - “greens” üBacillariophyta - “diatoms” üChrysophyta - “chrysophytes” üPyrrophyta - “dinoflagellates” üEuglenophyta - “euglenoids” Page 7
Pollution Indicators: Why are algae such good indicators? ØNaturally high population ØRapid response time ØIdentification to a species level ØEase of sampling Page 8
Pollution Indicators: Why are algae such good indicators? ØFast turnover ØEasy to collect in large numbers ØTolerance or sensitivity to specific environmental conditions known Page 9
Algae Page 10
Factors affecting algal growth and community composition Water chemistry (p. H, alkalinity, cations) Light (affected by turbidity, depth) Temperature Organic nutrients (naturally occurring or anthropogenic) Grazing Seasonality Page 11
Pollution Indicators: Rapid Bioassessment Objectives Assessment of: • Biomass • Species • Composition • Biological condition of Periphyton assemblages Page 12
Pollution Indicators: Phosphorus • Change in algal communities • Enriched conditions increase or decrease, depends on epiphytic/benthic, p. H, water regime, original state Page 13
Pollution Indicators: Species usually affected: Pandorina Dinobryon Scenedesmus Schroederia Anabaena Staurastrum Oscillatoria Aphanzinomenon Microsterias Pediastrum Closterium Microcystis Cosmarium Page 14
Algae as Bioindicators Lakes and streams with different physical, chemical and biological conditions will have different algal assemblages Therefore, algae are often used as bioindicators because of their habitat preferences Page 15
Thanks for attention! Page 16
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