Seasonal variability of Dinophysis spp. and Protoceratium reticulatum associated to lipophilic shellfish toxins in a strongly stratified Chilean fjord

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• 作者：Catharina Alves-de-Souza^a ; ¹ ; ^{cathsouza@gmail.com" class="auth_mail} ; Daniel Varela^a ; Cristó ; bal Contreras^b ; Pablo de La Iglesia^c ; Pamela Ferná ; ndez^a ; Byron Hipp^a ; Cristina Herná ; ndez^d ; Pilar Riobó ; ^e ; Beatriz Reguera^f ; José ; M. Franco^e ; Jorge Diogè ; ne^c ; Carlos Garcí ; a^b ; Né ; stor Lagos^b
• 关键词：Dinophysis acuminata ; Fjords ; Vertical distribution ; Dinophysistoxins ; Pectenotoxins ; Yessotoxins
• 刊名：Deep Sea Research Part II: Topical Studies in Oceanography
• 出版年：March, 2014
• 年：2014
• 卷：101
• 期：Complete
• 页码：152-162
• 全文大小：2166 K

文摘

The fine scale vertical distribution of Dinophysis spp. and Protoceratium reticulatum (potential producers of lipophilic shellfish toxins, LSTs) and its relation with LSTs in shellfish was studied in Reloncav铆 fjord, a strongly stratified system in Southern Chile. Samples were taken over two years from late spring to early autumn (2007-2008 period) and from early spring to late summer (2008-2009 period). Dinophysis spp., in particular Dinophysis acuminata, were always detected, often forming thin layers in the region of the salinity driven pycnocline, with cell maxima for D. acuminata of 28.5脳10³ cells L^鈭? in March 2008 and 17.1脳10³ cells L^鈭? in November 2008. During the 2008-2009 sampling period, blooms of D. acuminata co-occurred with high densities of cryptophyceans and the ciliate Mesodinium spp. The highest levels of pectenotoxin-2 (PTX-2; 2.2 ng L^鈭?) were found in the plankton in February 2009, associated with moderate densities of D. acuminata, Dinophysis tripos and Dinophysis subcircularis (0.1-0.6脳10³ cells L^鈭?). However, only trace levels of PTX-2 were observed in bivalves at that time. Dinophysistoxin (DTX-1 and DTX-3) levels in bivalves and densities of Dinophysis spp. were not well correlated. Low DTX levels in bivalves observed during a major bloom of D. acuminata in March 2008 suggested that there is a large seasonal intraspecific variability in toxin content of Dinophysis spp. driven by changes in population structure associated with distinct LST toxin profiles in Reloncav铆 fjord during the study period. A heterogeneous vertical distribution was also observed for P. reticulatum, whose presence was restricted to summer months. A bloom of this species of 2.2脳10³ cells L^鈭? at 14 m depth in February 2009 was positively correlated with high concentrations of yessotoxins in bivalves (51-496 ng g^鈭?) and plankton samples (3.2 ng L^鈭?). Our results suggest that a review of monitoring strategies for Dinophysis spp. in strongly stratified fjord systems should be carried out. They also indicate that early warning of LST events based on Dinophysis cell numbers are not reliable for seafood control.