Publication Abstract

Microalgae are the basis of marine food-webs, essential to sustain top-predators including seabirds. However, certain species of microalgae synthesize biotoxins which can accumulate in shellfish and fish and may cause harm to marine animals feeding on them. Toxins produced by dinoflagellates have been previously observed to be poisonous for seabirds. In freshwater and brackish habitats cyanobacteria have caused bird mortality events for their exposure to cyanotoxins . In this work, we analyze the prevalence of six families of biotoxins (Paralytic Shellfish Toxins-PSTs, microcystins- MCs, Anatoxins, Domoic Acid, Cylindrospermopsin and Tetrodotoxins) analyzed in 340 samples of 193 wild birds admitted in a wildlife rehabilitation center in south Portugal. Furthermore, we consider the clinical picture and signs of 17 birds that presented quantifiable levels of biotoxins in their tissues. The relationship between toxin burdens and the symptomatology observed, as well as the possible biotoxin sources are discussed. Based on previous published research data, we conclude that in these birds, the biotoxins are unlikely to be the only cause of death but might contribute to some extent to the reduction of birds’ fitness. On the other hand, the rapid excretion of highly hydrophilic toxins such as PSTs and the limited number of toxicological studies in birds make it difficult to ascertain the origin of the deadly disease.

Lucía Soliño, Andrew D. Turner^*, Begoña Ben-Gigirey, Ryan P. Alexander^*, Karl J. Dean^*, Robert G. Hatfield^*, Benjamin H. Maskrey^*, María Casero