N.H. Rev. Stat. Ann. § 143:21

No shellfish shall be harvested in New Hampshire for food unless taken from areas approved by the commissioner of the department of environmental services. If taken from out-of-state sources, shellfish harvested for food shall be taken from areas approved by the appropriate state regulatory shellfish authorities having jurisdiction, and secured from shellfish dealers currently listed on the United States Public Health Service publication of approved shellfish shippers.