Accumulation of diarrhetic shellfish poisoning toxins in the oyster Crassostrea gigas and the mussel Choromytilus meridionalis in the southern Benguela ecosystem

  • GC Pitcher
  • B Krock
  • AD Cembella

Abstract

Diarrhetic shellfish poisoning (DSP) poses a significant threat to the safe consumption of shellfish in the southern Benguela ecosystem. The accumulation  of DSP toxins was investigated in two cultivated bivalve species, the Pacific oyster Crassostrea gigas and the mussel Choromytilus meridionalis, suspended from a mooring located off Lambert’s Bay on the west  coast of South Africa. The dinoflagellate Dinophysis acuminata, a known source of polyether toxins associated with DSP, was common through most of the study period. The toxin composition of the dinoflagellate was dominated by okadaic acid (OA) (91%), with lesser quantities of the dinophysistoxin DTX-1 (6.5%) and pectenotoxin PTX-2 (2.4%), and traces of PTX-2sa and PTX-11. The mean cell toxin quota of D. acuminata was 7.8 pg OA cell–1. The toxin profile in shellfish was characterised by a notably higher relative content of DTX-1. The study showed the average concentration of DSP toxins in the mussels to exceed that in the oysters by approximately 20-fold. The results indicate a need to establish species-specific sampling frequencies in shellfish safety monitoring programmes.

Keywords: Benguela Current, Dinophysis acuminata, DSP toxins, LC-MS/MS, shellfish toxicity

African Journal of Marine Science 2011, 33(2): 273–281

Author Biographies

GC Pitcher
Branch: Fisheries Management, Department of Agriculture, Forestry and Fisheries, Private Bag X2, Rogge Bay 8012, South Africa; University of Cape Town, Private Bag, Rondebosch 7700, South Africa
B Krock
Alfred-Wegener Institut für Polar- und Meeresforschung, Am Handelshafen 12, 27570 Bremerhaven, Germany
AD Cembella
Alfred-Wegener Institut für Polar- und Meeresforschung, Am Handelshafen 12, 27570 Bremerhaven, Germany
Section
Articles

Journal Identifiers


eISSN: 1814-2338
print ISSN: 1814-232X