Freshwater Algae: Identification and Use as Bioindicators

104 3 ALGAE AS BIOINDICATORSLocal direct and diffuse loadfrom forestry activitiesALocal acid surfaceand groiund waterdischarges (rockyand sandy soils)Local and diffuseload from wetlandsPELAGICZONEBIndustrial effluentsCLITTORALZONEEffects and mixingof inflowing watersDiffuse load fromvillagesLocal direct and diffuse load from agricultureLocal and diffuseload from trafficFigure 3.2Lake water quality: phytoplankton and periphyton as bioindicators. General lake water quality: phytoplanktonin pelagic zone (° sites A, B, C). Local water quality at edge of lake ( • periphyton in littoral zone), with inputs(→) from a range of surrounding terrestrial sources. Figure adapted and redrawn from Eloranta, 2000. Suitability of water for human use. This includescompliance of water quality with regulations forhuman consumption and recreation. Build-upof colonial blue-green algal populations, withincreased concentrations of algal toxins, can leadto closure of lakes for production of drinking waterand recreation. The use of a reactive monitoringprogramme for blue-green algal development overthe summer months is now an essential part ofwater management for in many aquatic systems(e.g. Hollingworth Lake, United Kingdom – Sigee,2004). Conservation assessment. Analysis of freshwateralgae has become an important part of the surveyand data collection programme used in the evaluationof lakes for their nature conservation value(Duker and Palmer, 2009). Evaluation of water