Section 23. Every erection made and all work done within tide water, or within the waters of a great pond or outlet thereof, or on or within the banks of the Connecticut river, or the Merrimack river, below high water mark, not authorized by the general court or by the department, or made or done in a manner not sanctioned by the department, if a license is required as hereinbefore provided, shall be considered a public nuisance. Whoever creates such nuisance, (a) shall be punished by a fine of not more than twenty-five thousand dollars for each day such nuisance occurs or continues, or by imprisonment for not more than one year, or both such fine and imprisonment; or (b), shall be subject to a civil penalty of not more than twenty-five thousand dollars for each day such nuisance occurs or continues. The attorney general or the district attorneys within their respective districts shall, at the request of the department, institute proceedings to enjoin or abate such nuisance, or to restrain the removal of material from any bar or breakwater of any harbor.