# Natural Resources (GNR) ## Title 4. Fish and Fisheries ### Subtitle 5. Obstructing the Passage of Fish; Interference With Nets and Fishing, and Other Prohibitions Generally #### Section 4-501 An obstruction may not be placed at the mouth of any creek, cove, or inlet, or across any stream, so as to impound any fish and prevent its free passage to and from the water or its free access up and down the stream. However, a dam may be erected if fish ladders are maintained in accordance with the provisions of this subtitle. #### Section 4-502 (a) Every owner of a dam on waters of the State shall construct on the dam and keep repaired at least one fish ladder if the Department deems it necessary for ascending and descending of fish. Every fish ladder shall be constructed to allow anadromous fish free course up and down the waters at all times. (b) Any person intending to construct a dam on waters of the State shall file an application with the Department. Each application shall contain sufficient information to enable the Department to determine the necessity for constructing a fish ladder. The Department shall advise the applicant of its determination. (c) The Department and any other unit having jurisdiction shall approve the construction plan before the dam is constructed. (d) If the owner, operator, or lessee of a dam entered into an agreement prior to July 1, 1955, to pay the State an annual periodic sum of money instead of being required to erect a fish ladder or instead of being required to construct and maintain any fish way or fish ladder pursuant to the provisions contained in any charter previously granted to any corporation by any special or general State law, the provisions of the charter or agreement remain in effect. The amount of money paid to the State during each year may not be less than four and one-half percent of the estimated cost to erect the fish ladder, but not to exceed $4,000 annually. Any money paid to the Department shall be used to manage, rear, and distribute the fish actually placed in the water and to acquire any necessary facility for these purposes. One half of the funds received on behalf of the Conowingo Dam across the Susquehanna River shall be credited to the State Fisheries Management and Protection Fund. (e) The provisions of this section do not change any term, condition, or obligation imposed by a contract in force prior to July 1, 1955, between the owner of any dam and the State. (f) On application of the Department, verified by oath or affirmation, the circuit court for any county, sitting in equity, may enforce by injunction compliance with, or restraint from violating or attempting to violate, any provision of this section. (g) The Department shall investigate every violation of this section. If any person obstructs a stream by failing to make or keep in repair any fish ladder on the dam, the Department shall serve notice in writing on him requiring that he make or keep in repair the necessary fish ladder. The notice shall specify the penalty for the failure to act within its time limit. Any person who violates the notice is guilty of a misdemeanor and upon conviction is subject to a fine not exceeding $300, or imprisonment not exceeding three years, or both, with costs imposed in the discretion of the court. A separate offense exists on each day the person violates the notice. If the fine is imposed by the circuit court for any county, the fine when collected shall be remitted to the Department. #### Section 4-503 A person may not place, throw, or make use of any dynamite or other explosive substance in any water in the State, except for engineering, milling, or mining purposes. Any person who violates this section is guilty of a misdemeanor and upon conviction is subject to a fine not exceeding $300 or imprisonment not exceeding three years, or both, with costs imposed in the discretion of the court. #### Section 4-504 A person may not whip or beat any waters of the State with a pole, stick, or any other thing in order to drive fish into any device for catching fish. In Kent County and Queen Anne's County, this section applies only to waters of the Sassafras River and its tributaries. #### Section 4-505 A person may not molest, disturb, destroy, or catch and carry away fish belonging to another person from any boat, live box, crab pot, trot line, or the pocket or crib of any pound net or enclosed or gilled in any fish net of any kind, or take or carry away any net or gear belonging to another person used in catching fish. This section does not apply directly or indirectly to seine haulers actually engaged in laying and taking up nets when making a haul. #### Section 4-506 A person may not fasten, tie, or anchor any boat to or in any other way interfere with any other person's fishing nets, stakes, or other personal property in or close to the waters of the State. #### Section 4-506.1 (a) While on private or public land, or Maryland waters, a person may not for the purpose of disrupting a lawful fishing activity: (1) Interfere intentionally with the lawful taking of fish or other marine life by another person; (2) Intentionally harass, drive, or disturb any fish for the purpose of disrupting a lawful fishing activity; (3) Intentionally block, impede, harass, or disturb a person engaged in a lawful fishing activity; (4) Intentionally deny passage by creating or erecting barriers on public property or on private property without the landowner's prior permission to areas where a lawful fishing activity is permitted; or (5) Intentionally hinder a lawful fishing activity by placing obstacles or objects in waters of the State. (b) The conduct declared unlawful in this section does not include any incidental interference arising from lawful activity by private land users or users of land managed by the Department, including farmers, miners, or persons engaged in recreation. (c) A Natural Resources police officer or other police officer of the State who has probable cause to believe that a person has violated this section may: (1) Order the person to desist or to leave the area; or (2) Arrest the person who refuses to desist or to leave the area. #### Section 4-507 A person may not sink any obstruction in the berth or haul of any fishery, or deliberately interfere with the operation of a haul seine after it has been set and is being hauled. #### Section 4-508 A skipper, captain or other person commanding a vessel, float, or boat may not pass knowingly, wantonly, maliciously, or as a result of gross negligence, through any net lawfully placed and marked. Any person who violates this section is guilty of a misdemeanor and upon conviction is subject to a fine equal to the damages suffered by the owner or occupier of the fishery, and court costs. #### Section 4-509 A person may not use or attempt to use any electronic device on any boat in the waters of the State or on any aircraft within the State, or use or attempt to use any aircraft, to detect the presence of finfish for any purpose. However, fishermen may use depth finders from boats to detect the presence of finfish. A person also may not use or attempt to use any device that may lure finfish by electrical impulses. This section does not prohibit the Department from using any electronic or electrical device for scientific research, law enforcement or other purpose, nor prohibit use of a fathometer or depth recorder for navigational purposes. Any person who violates this section is guilty of a misdemeanor and upon conviction is subject to a fine not exceeding $1,000 or imprisonment not exceeding one year, or both, with costs imposed in the discretion of the court. #### Section 4-510 A person may fish with a speargun and spear in the waters of the State only under the rules and regulations, and control of the Department. A speargun as used in this section means any type of device used for propelling a spear underwater by any means other than manual in order to catch fish. #### Section 4-511 A person other than a duly authorized officer of the Department may not move, destroy, or deface any State buoy, marker, or monument placed in the waters of the State, or fasten, tie, or anchor any boat to it. #### Section 4-512 During the open season for migratory waterfowl, a person may not fish by any means within 500 yards of any stationary blind or blind site which is occupied and is being used for hunting migratory waterfowl. #### Section 4-513 Consistent with the requirements of any license issued by the federal Energy Regulatory Commission, a person who owns or operates a dam or obstruction on the waters of the State used for the generation of electric power and the Secretary shall cooperate to ensure the release of a sufficient flow of impounded water to maintain both water quality and aquatic habitat below the dam or obstruction. #### Section 4-514 Except during an emergency, a person may not fasten, tie, or anchor a boat to another person's commercial fishing equipment or device including the hedging, stakes, buoys, or anchors of the equipment or device. --- Md. Code Ann., Nat. Res. (as displayed at mgaleg.maryland.gov, October 16, 2026)