The Contamination And Monitoring Program Of Paralytic Shellfish Poisoning And Diarrhetic Shellfish Poisoning In The Pearl River Estuary

Harmful algae blooms (HABs), especially toxic species, have been outbreaking frequently in the Pearl River estuary and its adjacent areas in recent years. The frequency, intensity and geographic distribution of poisoning and death events caused by the harmful algae toxins have increased recently, especially for the most life-threatening algaes toxins, such as paralytic shellfish poisoning (PSP) and diarrhetic shellfish poisoning (DSP). Detection records about both the toxins in Pearl River estuary and its adjacent areas were reported in the previous documents, while no systematic monitoring programs were performed in this sea area. In order to understand the consistency of temporal, spatial and species distribution of the two toxins, this paper collected and determined 181 samples from 17 sampling sites in Pearl River estuary and its adjacent sea quarterly during December 2007 to May 2009.The conclusions can be drawn as follows:Part I:Contaminated characteristics of PSP in Pearl River estuary and its adjacent sea areas①There were some PSP contaminations for shellfish collected from Pearl River estuary and its adjacent sea areas, and the positive rate was up to 20.4%out of the total samples. The contents of PSP were generally low and under the the public health safety standard (400 MU/1OOg). The maximum content of PSP toxins was about 2.15Mu/g in Chlamys nobilis samples from both XiaYong on March 3rd,2009 and AoTou on March 4th,2009.②The positive rates of PSP showed a markedly seasonal differentiation., the rates reached the highest in winter, and the lowest in autumn③The geographical distribution of PSP was widely spread, while comparing other bays, PSP pollution was more serious in Pearl River estuary, Dapeng Bay and Daya Bay.④The shellfish species that were subjected to accumulate PSP included Ostrea cucullata, Atrina pectinata, Chlamys nobilis, Ostrea plicatula, Crassostrea rivularis.⑤The results showed that there were twelve components of PSP in the samples, dcGTX3,Cl,dcGTX2 and C2 were the principal profiles, GTX3,GTX4,GTX1,GTX2 and B1 were the second, but the high potency toxins (STX, NEO and dcSTX) had a low proportion.Part II:Contaminated characteristics of DSP in Pearl River estuary and its adjacent sea①DSP toxins pollution were highly investigated in Pearl River estuary and its adjacent sea areas, and the positive rate and over-standard rate of DSP were 36.5%and 25.4%out of the total samples, respectively,.②The positive rate and the over-standard rate of samples varied in different seasons. Genarally, both the positive rate and the over-standard rate showed gradually increase from the winter of 2007 to winter of 2008 while a slight decrease at the spring of 2009.③The spatial distribution of DSP showed a decreasing tendency from Daya Bay to Pearl River estuary to Dapeng Bay.④Some shellfish species collected from the estuary and adjacent coastal areas of The Pearl River showed a strong ability to accumulate DSP. The shellfish species that were subjected to contaminate DSP included Perna viridis, Chlamys nobilis, Paphia undulata, Atrina pectinata, Ruditapes philippinara, Meretrix meretrix, Corbicula fluminea, Ostrea cucullata, Pteria martensii, Ostrea plicatula, Crassostrea rivularis, Tegillarca granosa, Arcidae, Mytilus coruscus. Among these 14 species, the most susceptible species were Tegillarca granosa, Ostrea plicatula, Ruditapes philippinara, Atrina pectinata, Paphia undulata, Ostrea cucullata, Perna viridis, Chlamys nobilis, Meretrix meretrix.The biotoxin monitoring program in Pearl River estuary and its adjacent sea area was proposed and it included how to collect shellfish species, how to determine sampling frequency and station, methods of toxin analysis, threshold of public healthy safety and biotoxin management on the basis of the investigation.The results of the present would provide theoretical reference to the policies about improving and intensifying management to shellfish toxins, consequently, guaranteeing the safe consumption of shellfish and persistent development of aquiculture.