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Occurrence of toxic cyanobacterial blooms for the first time in L ake K araoun, L ebanon
Author(s) -
Atoui Ali,
Hafez Hala,
Slim Kamal
Publication year - 2013
Publication title -
water and environment journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.437
H-Index - 37
eISSN - 1747-6593
pISSN - 1747-6585
DOI - 10.1111/j.1747-6593.2012.00324.x
Subject(s) - bloom , algal bloom , phytoplankton , environmental science , population , cyanobacteria , chlorophyll a , water quality , ecological succession , eutrophication , spring bloom , environmental chemistry , nutrient , ecology , biology , botany , chemistry , genetics , demography , sociology , bacteria
The increasing occurrence of cyanobacterial bloom in freshwaters worldwide is of great importance because of public health risks. In addition, they are very likely to have negative impact on ecological and economic aspects. In this study, the seasonal succession of phytoplankton population in L ake K araoun in L ebanon was monitored from M ay 2009 to J une 2011. The physicochemical parameters of lake water were then monitored for 1 year, from J une 2010 until J une 2011, to correlate the physicochemical parameters with the phytoplankton population in the lake. Our results showed, for the first time in L ebanon, that the eutrophied L ake K araoun has been under the invasion of toxic cyanobacterial blooms since M ay 2009. The cyanobacterial bloom was persistent from late spring ( M ay) until late fall ( D ecember) for 2 consecutive years. The high water temperature in the summer season is the main factor that has been affecting the growth of the cyanobacteria. The most frequently encountered bloom‐forming species were M icrocystis aeruginosa and A phanizomenon ovalisporum , which were either present individually or coexistent. The obtained results showed that during the period of cyanobacterial bloom, a deterioration of water quality defined by low levels of dissolved oxygen, total dissolved solids, and electric conductivity was reported. During cyanobacterial bloom period, the concentration of the orthophosphate– P ( PO 4‐ P ) was very minimal. The measured high value of chlorophyll‐a concentration during cyanobacterial bloom period (48.6 μg/L ) was attributed to high photosynthetic activity. Cyanobacterial blooms can cause a variety of water‐quality problems in L ake K araoun in addition to human health risk.