N.H. Rev. Stat. Ann. § 674:69

No local legislative body shall adopt any ordinance that declares any commercial or recreational fishing operation to be a nuisance solely because it is a commercial or recreational fishing operation, or any zoning ordinance that unreasonably burdens or forces the closure of any commercial or recreational fishing operation, including any fishing operation conducted as a home occupation. Nothing in this subdivision shall prevent a local government from regulating commercial and recreational fishing operations, including by requiring the use of methods, structures, or appliances where such use will prevent, ameliorate, or remove conditions which create or may create a nuisance.