Shellfish Aquaculture in Maryland

The U.S. Army Corps of Engineers, Baltimore District, is committed to improving the health of the Chesapeake Bay through collaborative environmental restoration efforts, including oyster restoration, and permitting for commercial shellfish aquaculture projects. The progress made collectively to date, by the federal, state, and local partners, and other important stakeholders, to help restore the Bay -- demonstrates the immeasurable value in working together to achieve a common goal.

We recognize that oyster aquaculture ‎is a critical component to the economic and environmental health of our region, and we are in ongoing conversations with our partners to find ways to make our processes better in-order to achieve a balance between the development of these important projects and the protection of our natural resources. We have an obligation by law to come to the most responsible and fair decisions when considering permit applications. Through our processes, we ensure proposed projects do not negatively affect our nation's waterways or users of these waterways.

Maryland's aquaculture program was approved in 2011. 

The U.S. Army Corps of Engineers, Baltimore District, and the Maryland Department of Natural Resources (DNR) require a Joint State/Federal Application for state approval of Commercial Shellfish Aquaculture leases and federal authorizations pursuant to Section 10 of the Rivers and Harbors Act of 1899 and Section 404 of the Clean Water Act. The waters subject to state and federal jurisdiction generally are the Chesapeake Bay and the Coastal Bays as well as their tidal tributaries in Maryland.

About the Joint State/Federal Aquaculture Review Process

Baltimore District developed a Regional General Permit (RGP) for Commercial Shellfish aquaculture activities that was effective from Aug. 15, 2011, to Aug. 15, 2016. On Aug. 16, 2016, Baltimore District replaced the expiring RGP-1 by reinstating the 2012 Nationwide Permit (NWP) 48 for Commercial Shellfish Aquaculture activities. On March 20, 2017, Baltimore District announced 2017 NWP 48 would be used for Commercial Shellfish Aquaculture projects proposed within both the Chesapeake Bay and the Coastal Bays, as well as their respective tidal tributaries in Maryland. Currently, 2021 NWP 48 is approved in Maryland for these activities or an alternative form of approval may be sought as a Letter of Permission or as an Individual Permit.

NWP 48 authorizes the installation of buoys, floats, racks, trays, nets, lines, tubes, containers, and other structures into navigable waters of the United States, as well as discharges of dredged or fill material into waters of the United States (seeding, rearing, cultivating, transplanting and harvesting activities), associated with new and continuing commercial shellfish aquaculture operations in authorized project areas. The project area is identified through a lease or permit issued by an appropriate state or local government agency, a treaty, or any easement, lease, deed, contract, or other legally binding agreement that establishes an enforceable property interest for the operator.

The process requires submission of an application in order to receive both an aquaculture lease from Maryland DNR and a permit from the Corps. The joint permit application may be submitted to either Maryland DNR, (Maryland DNR Fisheries Service, Aquaculture Division, C-2, 580 Taylor Avenue, Annapolis, MD 21401), or to the U.S. Army Corps of Engineers, Baltimore District (2 Hopkins Plaza, Attn: Regulatory Branch, Baltimore, MD 21201). Both Corps authorization and a state lease are required before the proposed work and activities may be legally performed. Download The Joint State/Federal Application for a Commercial Shellfish Aquaculture lease and Federal permit (currently in the process of being revised). Application and instructions, along with additional information, can be found on Maryland DNR’s shellfish aquaculture program web site.

Nationwide permits provide a more streamlined and efficient process for obtaining Department of the Army authorizations than individual permits. In conjunction with Maryland DNR, Baltimore District receives shellfish aquaculture applications submitted to Maryland DNR, enabling both agencies to concurrently review projects. The joint application is submitted to Maryland DNR for review, where it is then forwarded to Baltimore District, prior to or near the same time as when Maryland DNR is completing their full review,  including an on-site survey and updated project plans from showing any changes since the application was originally submitted.

For general permits, the Corps’ goal is to make a permit decision 60 days after receipt of a federally complete application. More complex or larger projects use Individual Permits that require a public notice and have an issuance goal of 120 days from receipt of a federally complete application.

Baltimore District participates in Aquaculture Review Board meetings, chaired by Maryland DNR and attended by other agencies, including Maryland Department of the Environment, U.S. Coast Guard, National Marine Fisheries Service and Maryland Historical Trust. The District is working in cooperation with these agencies to identify trends that affect permit processing times and making changes where we can to provide more efficient and effective decision-making for commercial shellfish aquaculture projects in Maryland.

Baltimore District developed Regional Conditions for NWP 48 to ensure proposed commercial shellfish activities have minimal impacts on navigation and endangered species, as well as any other relevant public interest factors. The application provides information for the District’s review, as well as to satisfy notification requirements in order for the application to be considered complete. If Regional Conditions requirements are not met, the application is incomplete and cannot be processed or considered further for Baltimore District review. Requirements may include a description of structural spacing; the number and spacing of cages/floats/gear as well as the number of vertical and horizontal lines, buoys and markers; and may also include notifications to adjacent property owners, as well as including information identifying how adverse impacts to navigation, or ingress and egress to neighboring properties, was considered avoided by the proposed plans and layout.

Aquaculture Q&As

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Does my project need to be submitted for Maryland Historical Trust review (Historic Properties, Section 106)?

Non-federal applicants for commercial shellfish projects must submit a pre-construction notification (PCN) to the District engineer if the NWP activity might have the potential to cause effects to properties listed, or eligible for listing, in the National Register of Historic Places. Such an activity is not authorized until the requirements of Section 106 of the National Historic Preservation Act (NHPA) have been satisfied.

The PCN must state which historic properties might have the potential to be affected by the proposed NWP activity or include a vicinity map indicating the location of the historic properties or the potential for the presence of historic properties. The prospective permittee will be notified by Baltimore District within 45 days of receipt of a complete PCN whether NHPA Section 106 consultation is required. If more than 45 days, work still cannot begin until notification has been received. 

Assistance regarding information on the location of, or potential for, the presence of historic properties can be sought from the State Historic Preservation Officer, Tribal Historic Preservation Officer, or designated tribal representative, as appropriate. 

The Maryland Historical Trust (MHT) web site provides instructions on how to submit a project for MHT review and encourages consultation during preliminary project planning. Early consultation allows time to successfully complete the review in advance of construction and may help facilitate permit decisions. 


How long does it take to review and come to a decision on an aquaculture project?

Baltimore District is required to determine if an application under NWP #48 is complete within 30 days from the date of receipt and must also notify the applicant of any mandatory missing information within this timeframe. The goal is for the District to come to a permit decision (or issuance) within 60 days of receipt of a federally completed application for a qualifying project under a general or nationwide permit. More complex or larger projects use Individual Permits that require a public notice and have an issuance goal of 120 days from receipt of a federally complete application.

Two primary factors that cause delays in the permit review process are incomplete information and lack of legible plans within the application.

Permit decisions are made on a case-by-case basis , as no two permits are alike.  Each application has specific issues and impacts that must be objectively considered in relationship to weighing the potential benefits and detriments to the Chesapeake Bay and its users. Some of the most common issues that arise include potential impacts to navigation, recreation, endangered species, historic features and Tribal rights, as well as adjacent property owner concerns, conflicting water-use location, etc. 

The District’s review and approval timeframes may be longer when consultation with other agencies is required to comply with laws such as Section 7 of the Endangered Species Act (ESA) and Section 106 of the National Historic Preservation Act. The District is continuing to work cooperatively with NOAA/National Marine Fisheries Services to ensure that ESA reviews do not unduly delay aquaculture permit decisions, and has developed a programmatic agreement with NMFS to expedite the ESA review process.

Baltimore District and Maryland DNR processes may or may not be completed at the same time, depending on the application and any issues that may be raised during review. 

We work cooperatively with our partners to identify trends that affect permit processing times in order to understand what we can do to provide more efficient and effective decision-making for aquaculture projects in Maryland.


What are the endangered species in Maryland that require consultation?

Section 7(a) (2) of the Endangered Species Act (ESA) requires the Corps to ensure any action it authorizes, such as for a proposed aquaculture project, is not likely to jeopardize the continued existence of any federally listed species or result in the destruction or adverse modification of its designated critical habitat. The 2017 NWP, general condition 18, requires applicants to identify in their application whether the proposed activity might affect listed species or designated critical habitat and include the name(s) of the endangered or threatened species that might be affected by the proposed work or that use the designated critical habitat that might be affected by the proposed work.

Baltimore District issued a special public notice Jan. 29, 2016, to provide information regarding the NWP program and ESA. 

In the Chesapeake and Coastal Bays in Maryland, there are two species of endangered sturgeon (Atlantic and short-nose) and four species of threatened or endangered sea turtles (green, leatherback, loggerhead and Kemp’s ridley).The Endangered Species Act requires federal agencies to consult with the National Marine Fisheries Service or the U.S. Fish and Wildlife Service on actions that may affect threatened or endangered species or critical habitat. 

NOAA Fisheries hosts a web site with species maps that show where listed species are likely to be present based on geographic factors, time of year and biology. These maps provide technical assistance, but do not replace the Section 7 consultation process. They are intended to help determine if listed species or critical habitat may be affected by a proposed action, such as authorizing an aquaculture project. The presence of listed species and/or critical habitat, in combination with the nature of the activity, will help determine if consultation is needed. The Corps uses the best available scientific and commercial information as well as best professional judgment to determine if consultation is required, even if a map indicates a listed species is not currently present, or if there is no anticipated effect on the species or habitat. The Corps is required to come to this determination and notify the applicant of this determination within 45 days of receipt of a complete permit application. 

Additional information on listed species can be viewed on NOAA Fisheries marine life web page and their Greater Atlantic Regional Fisheries Office’s (GARFO) Protected Resources Division web page.

Questions on the proposed activity on a listed species should be directed to Baltimore District. 

The applicant cannot begin work until the Corps has provided notification the proposed activities will have “no effect” on listed species or critical habitat, or until Section 7 consultation has been completed.

In April 2017, the Army Corps North Atlantic Division and GARFO finalized a programmatic agreement for compliance with Section 7 of the ESA. This agreement provides a streamlined process for verification of proposed projects, including shellfish aquaculture. 

Baltimore District has made the following “effect determinations” generally for purposes of Section 7 of the ESA regarding whether activities authorized may affect ESA-listed species and for purposes of critical habitat. These are not definitive. Determinations are dependent on each project. 

Aquaculture Type

Federally listed threatened or endangered species


Shell on bottom on existing soft bottom (e.g., soft sand, mud)


May affect, but is not likely to adversely affect


May affect, but is not likely to adversely affect (Beneficial effect)

Shell on bottom on existing hard bottom (e.g., mixed shell, shell hash, hard sand, existing shell)


May affect, but is not likely to adversely affect


May affect, but is not likely to adversely affect (Beneficial effect)

Installation of Cages, Floats, Buoys, Lines, or Other Markers within the Water Column at or near the water surface


May affect, but is not likely to adversely affect (Beneficial effect)


May affect, but is not likely to adversely affect

Installation of Cages on the Bottom with Buoys, Lines, or Other Markers


May affect, but is not likely to adversely affect (Beneficial effect)


May affect, but not likely to adversely affect



What do I do if I have an interaction with a National Marine Fisheries Service federally threatened or endangered species?

An interaction is defined as an entanglement or capture of a listed species or a strike/direct contact between vessels or equipment used for the project and a listed species.

Any interaction between a sea turtle or any species listed now or in the future under federal law and the vessels associated with the project must be reported to the National Marine Fisheries Service as follows:

(1) If the animal appears alive and uninjured (i.e., breathing normally, no visible wounds, movement uninhibited), the permittee or its representative must report the incident to the National Marine Fisheries Service Northeast Region Marine Mammal and Sea Turtle Stranding and Entanglement Hotline at 866-755-6622 within 24 hours of the return trip from which the discovery was made;

(2) If the animal requires assistance, the call to the hotline must be made immediately;

(3) If the animal appears to be injured (i.e. bleeding, gasping for air, etc.) or dead, the permittee or its representative must also immediately call the hotline, so the appropriate rehabilitation or stranding network representative can be contacted. The applicant shall also notify the Corps of all correspondence and coordination with the National Marine Fisheries Service within two calendar days. Additional information about any federally threatened or endangered species may be obtained through NOAA's Fisheries web site


What types of activities are not authorized under the Nationwide Permit?

  • The cultivation of a nonindigenous species unless that species has been previously cultivated in the water body;
  • The cultivation of an aquatic nuisance species as defined in the Nonindigenous Aquatic Nuisance Prevention and Control Act of 1990;
  • Attendant features such as docks, piers, boat ramps, stockpiles, or staging areas, or the deposition of shell material back into waters of the United States as waste.; or
  • Activities that directly affect more than 1/2 an acre of submerged aquatic vegetation beds in areas that have not been used for commercial shellfish aquaculture activities during the past 100 years;
  • Activities located in mapped anadromous fish spawning habitat. The applicant may refer to MERLIN or other reliable sources for this information;  
  • Activities associated with the cultivation and/or introduction into tidal waters of shellfish species that are not indigenous to the Chesapeake Bay and its tributaries, or the Maryland coastal bays;
  • Activities associated with the mining of sub-tidal fossil shell deposits in waters of the Chesapeake Bay and its tributaries for use as cultch for a shellfish cultivation operation;
  • No work may extend into anchorage areas; customary boating channels; navigation fairways; marked, lighted, or charted channels; or State or Federal Navigation Channels;
  • Activities that adversely affect ingress to and egress from neighboring properties;
  • Commercial aquaculture activities for crustaceans or finfish;
  • Shellfish habitat restoration activities, including shellfish seeding that are conducted to restore populations of shellfish in navigable waters of the United States. Shellfish habitat restoration activities may be authorized by another form of Department of the Army permit (e.g., Nationwide Permit 27 or individual permit);
  • Activity or vehicular access to the project site that has more than a minimal adverse impact on coastal or wetland vegetation;
  • Oyster gardening activities;
  • The establishment of Aquaculture Enterprise Zones or pre-approved areas of the Atlantic Coastal Bays;
  • Activities that impound water;
  • Predator control devices (i.e., mesh fences, mesh nets, mesh tents) suspended or erected vertically or obliquely in the water column used to surround or enclose shellfish/containment gear. This condition does not preclude the use of cages for shellfish containment;
  • Activities that use unsuitable materials for shellfish seeding (e.g., asphalt, bituminous concrete, slag, tires, wallboard, plastic, wood, metal, crushed glass, trash and garbage);
  • Activities that will have more than minimal adverse effects on existing or naturally occurring beds or populations of shellfish, marine worms or other invertebrates that could be used by man, other mammals, birds, reptiles or predatory fish;
  • Activities that result in the physical destruction (e.g., through excavation, dredging, mining, fill or significant downstream sedimentation by substantial turbidity) of an important spawning/nursery habitat.

When does the Army Corps require Pre-construction Notification (PCN) of proposed commercial shellfish activities/operations?

  1. The project does not have a valid authorization from the Corps in effect as of Aug. 15, 2016; or
  2. The activity involves any change in the aquaculture type (bottom culture, floating structures, or structures suspended in the water column) from which was previously authorized by the Corps; or
  3. The activity will include a species that has never been cultivated in the water body; or
  4. The activity occurs in an area that has not been used for commercial shellfish aquaculture activities during the past 100 years.

Why are there differences between Virginia and Maryland for aquaculture?

Though both Baltimore and Norfolk Corps districts use NWP #48 to regulate aquaculture activities, there are still differences between Virginia and Maryland state permitting processes, due in part to differences in state laws, rules, and regulations regarding aquaculture. These variables result in differences in how aquaculture projects are reviewed within each state.   

The District’s goal is to strike a balance between allowing oyster aquaculture to the fullest extent possible – recognizing aquaculture’s contributions to the health of the Chesapeake Bay and the regional economy - while ensuring that projects do not have a negative effect on other natural resources, navigation, or generally on the public interest.

 Do applicants need sheathing on vertical lines as part of their aquaculture project?
Sheathing lines is not included as a regional condition to NWP #48 for aquaculture. In the past, during certain project-specific informal consultations, NMFS (pursuant to Section 7 of the Endangered Species Act) has recommended that vertical lines be sheathed to reduce the risk of entanglement with endangered sea turtles. The Corps has advanced these recommendations to applicants as a best practice, and applicants have indicated their willingness to sheath vertical lines for their projects.


 What information does the permit application require? 

To qualify for NWP authorization, the prospective permittee must comply with the following regional conditions and any case-specific special conditions imposed by the Corps. The general conditions are located in the 2017 NWPs as published in the Federal Register. Baltimore District added “Regional Conditions” to the 2017 NWP 48 to require the application/Pre-construction Notification (PCN) to the Corps (Regional General Condition 32) include the following information in addition to information required by General Conditions:

  1. A copy of the lease or permit issued by the appropriate state government agency if a lease or permit has been issued at the time of PCN submittal;
  2. Legible project vicinity map (black line on white background), to scale, and depicting the footprint of project area relative to prominent land/water geographic features, including approximate latitude/longitude coordinates of the project footprint;
  3. Legible overview plans (black line on white background), to scale (100’:1”, or 50’:1”), depicting the entire project footprint and adjacent waters overlaid on composite mapping of the five most recent years of SAV data (derived from the Virginia Institute of Marine Science (VIMS) SAV aerial surveys), and showing local water depths (bathymetry) of the project area, and other important ecological features of the site (e.g., native tidal marsh) that may be affected by project activities;
  4. Detailed project description, with the following information:
    1. Description of proposed activities, including site preparation and harvest activities (e.g., dredging, harrowing and dragging of bottom substrate, tonging), and a description of how structures and vertical and horizontal lines would be arranged throughout the project area, spacing of rows and spacing between structures;
    2. Types of aquaculture gear to be used, including anchoring devices, maximum number of vertical and horizontal lines, and buoys;
    3. Acreage of project footprint affecting bottom and water column;
    4. Impacts (temporary and/or permanent) to aquatic areas required for access to the aquaculture facility/gear, and remedial measures proposed to restore temporarily affected aquatic areas;
    5. Substrate type of bottom affected by proposed activities (particularly for on-bottom activities) (e.g., soft sand, hard sand, mud, shell.).
  5. Cross-sectional view of proposed aquaculture structures and all associated apparatus that represent the proposed operations of the activity (on- bottom, suspended, or floating);
  6. If the applicant proposes work in waters adjacent to property owned by others, the applicant must provide proof of notification to adjacent property owners via certified mail (click to view fillable example letter), return receipt requested. In addition, the applicant may include any statement of no objection or comments from the adjacent property owner(s). 
  7. The PCN must include details that clearly identify how adverse effects to navigation and ingress to and egress from neighboring properties have been avoided.

Additional Resources


Commercial Shellfish Aquaculture Outreach

This web page will be updated periodically with information where local oyster farmers, stakeholders, and others with interest in commercial shellfish aquaculture in the state of Maryland, can learn about the Corps involvement, as well as changes to the federal aquaculture regulatory permitting process when they occur. 

Resources from Aquaculture Workshop, March 21, 2019

Information in the presentation materials includes the permit application/leasing process, key considerations when developing a shellfish aquaculture project, pre-construction notification requirements, siting and navigation considerations, compliance with permit conditions, and coordination with adjacent property owners. 

U.S. Government Accountability Office Report: "Information on Shellfish Aquaculture Permitting Activities"

GAO released this report Feb. 21, 2019. GAO was asked to review the Corps' process for authorizing shellfish aquaculture activity in U.S. coastal waters. This report describes, for 2012 through 2017, (1) the number and outcomes of the applications the Corps received for shellfish aquaculture activities and the types of permits the Corps used to authorize such activities, and (2) the experiences of permit applicants in selected Districts in seeking Corps' authorization for their shellfish aquaculture activities. GAO found that the Corps, nationwide, authorized most (87 percent) of the 3,751 shellfish aquaculture applications it received from 2012 through 2017, according to Corps data. The Corps denied less than 1 percent, and the rest were withdrawn. Of the 19 Corps Districts that have coastal waters within their geographic areas of responsibility, 17 Districts received and authorized applications. GAO reviewed detailed information from a non-generalizable sample of 15 permit applications and interviewed the applicants and Corps officials from four Corps Districts, selected to reflect variation in geographic location and shellfish activity. Their experiences are highlighted in the report. View fast facts, highlights and the full report on GAO's web page.