MERJEM BUSHATI¹*, ERLINDA KONI², ROZARTA NEZAJ3
|
1Department of Food Science and Biotechnology, 3Department of Food and Nutrition, Research Center Faculty of Biotechnology and Food, Agricultural University of Tirana, 1025, Street Paisi Vodica, Tirana, Albania 2Department of Food and Veterinary Microbiology, Institute of Food Safety and Veterinary, Street “Aleksander Moisiu”, No.10, Tirana, Albania
Abstract The consumption of shellfish can be life-threatening when marine biotoxins exceed certain safety thresholds. One of the most important of shellfish harvesting and farming areas in Albania, is Butrint Lagoon, a long-standing aquaculture site for the Mediterranean mussel (Mytilus galloprovincialis). In 2023, we monitored phytoplankton in Butrint Lagoon on a monthly basis to identify seasonal bloom patterns and the environmental conditions. Pseudo-nitzschia clearly dominated the system. Algal concentrations remained low throughout winter and spring, began to rise in late summer, and peaked in autumn. Monitoring recorded up to 9.3×10⁴ cells L⁻¹ in October, while in November revealed a bloom of Pseudo-nitzschia (4.5×105 cells L⁻¹). Alexandrium was scarce, appearing only briefly and at low concentrations in May and August. The autumn bloom developed under warm (23–26 °C), moderately saline (26–28 ‰), and low-oxygen (7–8 mg L⁻¹) conditions, with increased rainfall. A simple regression model suggested a tendency for higher phytoplankton counts during warmer, rainier, and slightly higher-pH conditions, and lower counts when salinity and dissolved oxygen increased. The lagoon shows more frequent Pseudo-nitzschia increases, than Alexandrium events typically below critical thresholds. Results suggest that autumn poses a higher risk for harmful algal blooms (HABs), emphasizing the need for continuous monitoring to ensure food safety and protect public health. Keywords: Harmful algal blooms, Pseudo-nitzschia, phytoplankton seasonality. |