Paralytic and Amnesic Shellfish Toxins Impacts on Seabirds, Analyses and Management

Abstract

Marine biotoxins have been frequently implicated in morbidity and mortality events in numerous species of birds worldwide. Nevertheless, their effects on seabirds have often been overlooked and the associated ecological impact has not been extensively studied. On top of that, the number of published studies confirming by analyses the presence of marine biotoxins from harmful algal blooms (HABs) in seabirds, although having increased in recent years, is still quite low. This review compiles information on studies evidencing the impact of HAB toxins on marine birds, with a special focus on the effects of paralytic and amnesic shellfish toxins (PSTs and ASTs). It is mainly centered on studies in which the presence of PSTs and/or ASTs in seabird samples was demonstrated through analyses. The analytical techniques commonly employed, the tissues selected and the adjustments done in protocols for processing seabird matrixes are summarized. Other topics covered include the role of different vectors in the seabird intoxications, information on clinical signs in birds affected by PSTs and ASTs, and multifactorial causes which could aggravate the syndromes. Close collaboration between seabird experts and marine biotoxins researchers is needed to identify and report the potential involvement of HABs and their toxins in the mortality events. Future studies on the PSTs and ASTs pharmacodynamics, together with the establishment of lethal doses in various seabird species, are also necessary. These studies would aid in the selection of the target organs for toxins analyses and in the postmortem intoxication diagnoses.

Current Trends and New Challenges in Marine Phycotoxins

“…PSTs can enter the food web when toxin-producing dinoflagellates or cyanobacteria are ingested by shellfish, copepods, or other invertebrates and these, in turn, are consumed by larger organisms. Ingestion of PSTs by mammal and bird species can result in muscular weakness, motor incoordination, respiratory paralysis, and death [ 101 , 102 ].…”

Unknown Extracellular and Bioactive Metabolites of the Genus Alexandrium: A Review of Overlooked Toxins

“…This probably is due to their rapid accumulation in filter-feeding bivalves and their high toxicity in humans after consumption of contaminated shellfish [74]. PSTs are also associated with deleterious effects in seabirds [75] and marine mammals [56,76]. PSTs were already reported in the first half of the 20th century [77] and comprise a group of over 40 variants, not only produced by Alexandrium (including Centrodinium punctatum, which cluster within Alexandrium) but also by two other species of different genera (Gymnodinium catenatum H.W.Graham and Pyrodinium bahamense L.Plate), as well as several species of different genera of freshwater cyanobacteria.…”

The Common Sunstar Crossaster papposus—A Neurotoxic Starfish

“…STXs also have a wide effect on marine organisms [75], such as starfish [60], fish [40,42,76], bivalve molluscs [77,78], gastropods [73] and sea urchins [79]. Exposure to STXs can also affect marine mammals such as whales, seals [44,45] and otters [46], as well as sea birds [80][81][82][83]. This study sought to extensively map out the level of sunstar toxicity around the UK coast and, ultimately, to better understand any geographical or physiological drivers of toxin presence.…”