12th International Conference on Harmful Algae

INTERNATIONAL SOCIETY FOR THE STUDY OF HARMFUL ALGAE12 th <strong>International</strong> <strong>Conference</strong> on Harmful Algae, Copenhagen, Denmark, 4-8 September 2006local clays (ball clay, brownbentonite and white clay) andmarine sediments was determinedin a microscale set up. Ball clayexhibited high removal efficiency of>99% at final concentration of 1 g/L.Removal efficiency was 69% forbrown bentonite, 48% for white clay,and 59% for marine sediments.Cell removal of ball clay wasconsistent from 2.5 to 24 h after clayaddition. The effectiveness of ballclay was also tested against otherHAB species, Chatonella marinaand Amphidinium carterae, showingcell removal of 25% and 50%,respectively. Mesoscaleexperiments will be done for theefficacy of ball clay on larger volumeand under turbulent condition. Theeffect of ball clay addition onseawater chemistry showed nochange in ambient ammoniaconcentration but nitrate decreasedafter 5 and 24 h of clay addition.Results for nitrite and phosphatevaried between two runs.PO.13-67Harmful algal blooms along theKerala coast, southern IndiaSession: PO.13 - Regional eventsK PadmakumarUniversity of Kerala, TRIVANDRUM, IndiaDuring 9 – 21 September 2005, thecoastal regions from Kollam toVizhinjam of Kerala experiencedmassive fish kills followed byobnoxious and nauseating smell forabout a 100-km stretch along thecoast. The coastal waters hadstrong discolouration and highconcentration of Cochlodiniumpolykrikoides. There was a drasticdecline in the concentration ofoxygen, nitrite, nitrate andphosphate during the initial bloomperiod. The concentration of thedinoflagellates ranged from 2.5 to4.7 X 10 6 cells L -1 . This resulted in aserious health hazard as more than200 persons, especially schoolchildren were admitted in hospitals.It also adversely affected themussel and fin- fish fishery alongthe coast. The mouse bioassayrevealed no toxicity in mussels.Subsequent to this event, anothermassive fish kill had occurred atVarkala on 27 September 2004,which coincided with highconcentration of Ceratium furca (1.6X 10 4 cells L -1 ) and Cochlodiniumpolykrikoides (2.2 X 10 4 cells L -1 ).The HAB is a recurringphenomenon along the Keralacoast. Currently a nationalcoordinated monitoring programme'Harmful Algal Blooms in the IndianEEZ' is being carried out along thesouthern coasts of India.PO.14-03Modified local soils/sediments forHAB removal and macrophytesrestoring in shallow lakesSession: PO.14 - MitigationG Pan, M Zhang, H Zou, H Chen, BTian, X Yuan, S GaoRes. Cent. Eco-environ. Sci., BEIJING,ChinaThe major concerns for mitigatingHAB using clays in shallow lakesare low HAB removal efficiency formost clays in fresh waters; high clayloading and operating costs;ecological risks for adding exoticclays; re-suspension of algal cellsand increased anaerobic release ofnutrients/pollutants from thesediment; and the inherentincapability for preventing theoccurrence of HAB from long pointof view. We proposed a MLSIER(PCT patent filed) technology(modified-local-soils/sediments256