Abstract:
The accumulation pattern of organochlorine pesticides in green mussel (Perna viridis) was studied at Angsila, Chonburi Province between February and August 2000. Organochlorine pesticides in sediment and plankton samples were determined during the same period. Lindane (y-BHC), heptachlor, heotachlor-exoxide, aldrin, dieldrin, endrin, endrin aldehyde, p,p'-DDT, p,p'-DDE, p,p'=DDD, endosulfan-1, endosulfan-2, endosulfan sulfate were those pesticides found in the sediment. The same group of pesticides was found in the sediment except p,p'-DDT and endosulfan sulfate which were found in mussel tissue. The same group of pesticides was found in mussel except endrin, endrin aldehyde, p,p'-DDD. The most frequently found pesticide in green mussel and sediment were p,p'-DDE whereas endosulfan-1 was the most frequently pesticide found in plankton. Quantitatively, heptachlor was found at the highest concentration in all samples and this phenomenon occurred between April to June which was the beginning of the rainy season. In general, the accumulation pattern of organochlorine pesticides in green mussel varied with time, mussel size and sex. Most of the pesticide concentration decreased with increasing mussel size and did not relate with fat content in the mussel. Between March and May when female mussel were mature, pesticides found in the females were higher than that in males. The Relationship between quantity of organochlorine pesticides in mussel and plankton was observed but the content in plankton were generally higher than those in mussel and sediment. Hence, a biomonitoring program using mussel as a bioindicator at the time of sampling, sex and size of mussel must be included as important factors in order to obtain interpretable results.