I don't believe many shellfish are inherently poisonous to people, but I'm sure some are. More importantly they can certainly be harmful even if they aren't poisonous and some areas can be closed for clamming due to poor water quality, pollution, or to help maintain the shellfish populations. Some areas might have a restrictions on the amount of certain breeds of shellfish you are allowed to harvest. In some areas you even need a license to harvest shellfish, just like you'd need one to hunt or fish.
For your own safety, and to help preserve the habitats of these creatures, you need to do a great deal more research on the specific beach and local laws governing harvesting shellfish. [ Razhie's advice column | Ask Razhie A Question ]
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