Marinović Zoran, Tokodi Nada, Backović Damjana Drobac, Šćekić Ilija, Kitanović Nevena, Simić Snežana B, Đorđević Nevena B, Ferincz Árpád, Staszny Ádám, Dulić Tamara, Meriluoto Jussi, Urbányi Béla, Lujić Jelena, Svirčev Zorica
Department of Biology and Ecology, Faculty of Sciences, University of Novi Sad, 21000 Novi Sad, Serbia.
Department of Aquaculture, Institute of Aquaculture and Environmental Safety, Hungarian University of Agriculture and Life Sciences, 2100 Gödöllő, Hungary.
Microorganisms. 2021 Apr 29;9(5):960. doi: 10.3390/microorganisms9050960.
Lake Balaton is the largest shallow lake in Central Europe. Its water quality is affected by its biggest inflow, the Zala River. During late 20th century, a wetland area named the Kis-Balaton Water Protection System (KBWPS) was constructed in the hopes that it would act as a filter zone and thus ameliorate the water quality of Lake Balaton. The aim of the present study was to test whether the KBWPS effectively safeguards Lake Balaton against toxic cyanobacterial blooms. During April, May, July and September 2018, severe cyanobacterial blooming was observed in the KBWPS with numbers reaching up to 13 million cells/mL at the peak of the bloom (July 2018). MC- and STX-coding genes were detected in the cyanobacterial biomass. Five out of nine tested microcystin congeners were detected at the peak of the bloom with the concentrations of MC-LR reaching 1.29 µg/L; however, accumulation of MCs was not detected in fish tissues. Histopathological analyses displayed severe hepatopancreas, kidney and gill alterations in fish obtained throughout the investigated period. In Lake Balaton, on the other hand, cyanobacterial numbers were much lower; more than 400-fold fewer cells/mL were detected during June 2018 and cyanotoxins were not detected in the water. Hepatic, kidney and gill tissue displayed few alterations and resembled the structure of control fish. We can conclude that the KBWPS acts as a significant buffering zone, thus protecting the water quality of Lake Balaton. However, as MC- and STX-coding genes in the cyanobacterial biomass were detected at both sites, regular monitoring of this valuable ecosystem for the presence of cyanobacteria and cyanotoxins is of paramount importance.
巴拉顿湖是中欧最大的浅水湖。其水质受最大支流佐洛河的影响。在20世纪后期，一个名为小巴拉顿湖水质保护系统（KBWPS）的湿地地区建成，希望它能起到过滤区的作用，从而改善巴拉顿湖的水质。本研究的目的是测试KBWPS是否能有效保护巴拉顿湖免受有毒蓝藻水华的影响。在2018年4月、5月、7月和9月期间，在KBWPS中观察到严重的蓝藻水华，在水华高峰期（2018年7月）数量达到每毫升1300万个细胞。在蓝藻生物量中检测到了微囊藻毒素（MC）和石房蛤毒素（STX）编码基因。在水华高峰期检测到了9种受试微囊藻毒素同系物中的5种，MC-LR浓度达到1.29微克/升；然而，在鱼组织中未检测到微囊藻毒素的积累。组织病理学分析显示，在整个调查期间获得的鱼中，肝胰腺、肾脏和鳃出现严重病变。另一方面，在巴拉顿湖中，蓝藻数量要低得多；在2018年6月检测到的细胞数量比KBWPS少400多倍，并且在水中未检测到蓝藻毒素。肝、肾和鳃组织几乎没有变化，类似于对照鱼的结构。我们可以得出结论，KBWPS起到了重要的缓冲区作用，从而保护了巴拉顿湖的水质。然而，由于在两个地点都检测到了蓝藻生物量中的MC和STX编码基因，定期监测这个宝贵的生态系统中蓝藻和蓝藻毒素的存在至关重要。
