Species occurrence of the potentially toxigenic diatom genus Pseudo-nitzschia and the associated neurotoxin domoic acid in the Argentine Sea

Abstract

Keywords:Amnesic shellfish poisoning South-western Atlantic Pseudo-nitzschia diversity P. australis P. brasiliana Domoic acid A B S T R A C TThe marine diatom genus Pseudo-nitzschia, the major known producer of the neurotoxin domoic acid (DA) responsible for the amnesic shellfish poisoning (ASP) syndrome in humans and marine mammals, is globally distributed. The genus presents high species richness in the Argentine Sea and DA has been frequently detected in the last few years in plankton and shellfish samples, but the species identity of the producers remains unclear. In the present work, the distribution and abundance of Pseudo-nitzschia species and DA were determined from samples collected on two oceanographic cruises carried out through the Argentine Sea ($39-47 S) during summer and spring 2013. Phytoplankton composition was analysed by light and electron microscopy while DA was determined by liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). The genus Pseudo-nitzschia was recorded in 71 and 86% of samples collected in summer and spring, respectively, whereas DA was detected in only 42 and 21% of samples, respectively. Microscopic analyses revealed at least five potentially toxic species (P. australis, P. brasiliana, P. fraudulenta, P. pungens, P. turgidula), plus putatively non-toxigenic P. dolorosa, P. lineola, P. turgiduloides and unidentified specimens of the P. pseudodelicatissima complex. The species P. australis showed the highest correlation with DA occurrence (r = 0.55; p < 0.05), suggesting its importance as a major DA producer in the Argentine Sea. In the northern area and during summer, DA was associated with the presence of P. brasiliana, a species recorded for the first time in the Argentine Sea. By contrast, high concentrations of P. fraudulenta, P. pungens and P. turgidula did not correspond with DA occurrence. This study represents the first successful attempt to link toxigenicity with Pseudo-nitzschia diversity and cell abundance in field plankton populations in the south-western Atlantic.

Occurrence of Marine Biotoxins and Shellfish Poisoning Events and Their Causative Organisms in Argentine Marine Waters

“…Distribution along the entire Argentine coast has been reported for P. pungens (Balech, 1976;Lange, 1985; R.M. Negri and Inza, 1998;Ferrario et al, 1999Ferrario et al, , 2002Gayoso, 2001;Sastre et al, 2001;Sar et al, 2006;Almandoz et al, 2007Almandoz et al, , 2017Sunesen et al, 2009;Cadaillón, 2012;Krock et al, 2015a).…”

“…The next species to be reported was Pseudo-nitzschia australis in the San Matías Gulf (41°S; Frenguelli, 1939), which later turned out also to be present in the entire Argentine Sea (Hasle, 1965;Lange, 1985) as P. pseudoseriata (Ferrario and Galván, 1989;Sastre et al, 1997Sastre et al, , 2001R.M. Negri and Inza, 1998;Sar et al, 1998;Ferrario et al, 1999Ferrario et al, , 2002Ferrario et al, , 2017Montoya et al, 2000;Santinelli et al, 2002;Almandoz et al, 2007Almandoz et al, , 2011Almandoz et al, , 2017Cadaillón, 2012;Krock et al, 2015a).…”

“…Amnesic shellfish poisoning (ASP; Montoya et al, 2000Montoya et al, , 2008 R.M. Negri et al, 2004;Sastre et al, 2007;Cadaillón, 2012;Krock et al, 2015a;Almandoz et al, 2017), 2. Paralytic shellfish poisoning (PSP; Carreto et al, 1981Carreto et al, , 1986Carreto et al, , 1998Carreto et al, , 2007Esteves et al, 1992;Benavides et al, 1995;Akselman et al, 1998;Gayoso, 2001; Montoya et al, 2006Montoya et al, , 2018Santinelli et al, 1994aSantinelli et al, , 2002Cadaillón, 2012;Sunesen et al, 2014;Krock et al, 2015a), 3.…”

Occurrence of Toxigenic Microalgal Species and Phycotoxin Accumulation in Mesozooplankton in Northern Patagonian Gulfs, Argentina

“…However, in the present study the identification of a bloom of P. australis in net tow samples, and the high cell densities of this species observed in bottle samples in Golfo Nuevo in October, suggest that this species was the main producer of the highest levels of domoic acid. In the Argentine Sea, P. australis has been suggested to be the major producer of domoic acid (Almandoz et al ). Furthermore, P. australis is considered to be a strong domoic acid producer (12–37 pg cell –1 ; Bates ; Kotaki et al ), and for this reason it has been reported to be the most toxic species of the genus Pseudo‐nitzschia (Trainer et al ) and to be primarily responsible for ASP problems worldwide (Bates ; Fire et al ).…”

“…Furthermore, P. australis is considered to be a strong domoic acid producer (12–37 pg cell –1 ; Bates ; Kotaki et al ), and for this reason it has been reported to be the most toxic species of the genus Pseudo‐nitzschia (Trainer et al ) and to be primarily responsible for ASP problems worldwide (Bates ; Fire et al ). Therefore, it is worth highlighting the simultaneous detection of the highest levels of domoic acid and major densities of P. australis in the Argentine Sea (Negri and Inza ; Sastre et al ; Negri et al ; Almandoz et al , ) because proliferation of this species may pose a risk for fishery activities in the region that are focused on the Tehuelche scallop ( Aequipecten tehuelchus ) in Golfo San José (Orensanz et al ) and on several species of marine animals that feed and reproduce in both gulfs.…”