Historical occurrence of HCBs (Harmful Cyanobacterial Blooms) and cyanotoxins in Portugal over the past decades

• Autor(a) principal: Carmo, Pedro Daniel Lopes
• Data de Publicação: 2022
• Tipo de documento: Dissertação
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10773/36413
• topic: Cyanobacteria; Cyanotoxins; Portugal; Blooms

Cyanobacteria are a morphologically diverse group that has been associated with negative consequences for aquatic life, as well as for terrestrial organisms, including humans. A cyanobacterial bloom is characterized by a visible green colouration at the surface of the water as a result of biomass accumulation due to rapid and excessive cyanobacterial growth, contributing to the degradation of water quality and putting at risk the functioning of the ecosystem. This dissertation summarizes past and current research on the occurrence of toxic cyanobacteria in Portugal, by recovering historical data from international scientific journals reported for Portugal over the past decades. In Portugal, the records of cyanotoxins occurrence are limited and scattered in space and time. The most frequently reported cyanotoxins are microcystins, in lakes (such as Mira and Vela) and reservoirs (Torrão, Carrapatelo, Aguieira, Alvito, Odivelas, Monte Novo, Enxoé and Roxo) and linked to blooms of Microcystis, Aphanizomenon and Planktothrix species. Anatoxin-a was detected in strains of Anabaena and Aphanizomenon from reservoirs (Maranhão) and wastewater from water treatment plants. Saxitoxins were recorded at Montargil and Crestuma reservoirs, during Aphanizomenon flos-aquae blooms. Cylindrospermopsin was recently detected in lakes (Vela and São Brás). The increased occurrence of cyanotoxins reinforces the urgent need for increased research, surveillance, and monitoring, implementing global regulations but considering local management according to local specificities and ecology.