Toxic <i>Nodularia spumigena</i> blooms in the coastal waters of the Gulf of Gdańsk: a ten-year survey

• Main Authors: Hanna Mazur-Marzec, Adam Kr&#x0119;&#x017C;el, Justyna Kobos, Marcin Pli&#x0144;ski
• Format: Article
• Language: English
• Published: Elsevier 2006-06-01
• Series: Oceanologia
• Subjects: <i>Nodularia spumigena</i>; Nodularin; remote sensing; Gulf of Gdańsk
• Online Access: http://www.iopan.gda.pl/oceanologia/48_2.html#A5

In the Baltic Sea, summer blooms of the filamentous, nitrogen-fixingcyanobacterium <i>Nodularia spumigena</i> are favoured by high P concentrationsat low N:P ratios and a salinity range of 5-13 PSU. The bloomsare initiated by calm and sunny weather, an elevated surfacewater temperature and thermal stratification. The mass occurrenceof <i>N. spumigena</i> in coastal waters is a matter of special concern,as the cyanobacterium produces nodularin, a potent pentapeptidehepatotoxin. In the Gulf of Gdansk, the large-scale occurrenceof <i>N. spumigena</i> was recorded for the first time in 1994. Bloomsof a similar intensity occurred in 2001, 2003 and 2004. Nodularinconcentrations in freeze-dried bloom samples varied from 0.01to 4.01 mg g^-1 d.w. In the coastal waters of the Gulf of Gdańsk,cell-bound nodularin concentrations in 2004 and 2005 attainedmaxima of 25852 ± 107 µg dm^-3 and3964 ± 125 µg dm^-3, respectively. Microscopic analysis revealedthe presence of diverse <i>N. spumigena</i> forms, with the dominance of curvedfilaments in bloom samples. The results of <i>in situ</i> studies and remotesensing measurements indicate a high frequency and intensity of cyanobacterialblooms in the Gulf of Gdańsk in the last ten years.