Beware this coming crayfish season! While there are set allowable amounts for heavy metals, antibiotics, hormones (and apparently even opium) in crayfish, there is apparently no standard for pesticide levels. This is particularly alarming as last month Chongming County fisherman were caught dumping pesticides in rivers to more easily nab the critters. Shanghai: where the line between food producer and Orkin exterminator is a thin one.