Paralytic shellfish toxins in mussels and Alexandrium tamarense at Valdes Peninsula, Chubut, Patagonia Argentina: Kinetic of a natural depuration.

ANDRINOLO, D., SANTINELLI, N., OTAÑO, S., SASTRE, V., AND LAGOS, N

JOURNAL OF SHELLFISH RESEARCH

NATL SHELLFISHERIES ASSOC

Año: 1999 vol. 18 p. 203 - 209

0730-8000

Paralytic shellfish toxin profiles of Alexandrium tamorense( Lebour) Balech and mrossel(sA ulacomyaa ter) cortaÍrinated by the dinoflagellate, were obtained from eight sampling stations along the Valdés Peninsula, Chubut, Argentina. The samples were collected from November 1995 to May 1996. The data show, that the monitoring began after an outbreak during a bloom ofÁ. tamarenseT. he highestc ell densitiesw eref oundi n November1 995a t Bengoa( 1.81x 103c ells/L) andL arr¿lde( 1.2 x ld cell´r/L), both stations are located in the San José Gulf. Occurrence of other species of phytoplankton are also reponed. A. tamnrense was never rnor" th* 27o ofthe total phytoplanktonp opulation. Low temperaturesa nd high salinity were found in November 1995, when the highestA . tanarense cell density was observed.U sing a postcolumnd erivatizationh igh-performanceli quid chromatography( IIPLC) analysis,t he PSP toxin profiles of Patagonianc oast phytoplanktona nd mussels amplesw ere obtainedf or the first time. The average PSPt oxin profile ofover 30 mussels amplesfr om all monitorings tationss howedt he gonyautoxinsl- 4 (GTX l-4) epimerst o be the most abundant PSP toxins. These epimers were the most prevalent ones in the A. tamarense present in the ph¡oplankton samples analyzed. Other PSP toxins quantified in mussel samples were: STX, dcSTX, and C1-C4. NeoSfi was never found in mussel or phytoplankton samples. The highest toxicity in the phytoplankton samples was 490 fmol of PSP toxinVcell and mussels 631 pg STX eq./100 g, both of v¡hich were obtained in November, 1995. The decrease of the toxicity in the filter feeder Aulacomya ater, oc.ctJrs following an exponential decay of the first order, showing that, in the San José Guli Valdés Peninsula, the natural depuration process of A. ater canb e interpretedb y a one-compartmenmt odel. According to the detoxification rate determinedf or A. aten a native South American filter-feeder bivalve, can be classified as a rnoderate detoxifier.