Maryland Department of the Environment

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MD Shellfish Harvesting Areas​

Maryland's Shellfish Harvesting and Closure Area Map

 

Maryland's Shellfish Harvesting and Closure Area Map

The map generally depicts the classification of shellfish waters of the State: restricted, conditionally approved, or approved. This map shows the current classifications. 

Shellfish harvesting waters which are open or approved for harvesting are those where harvesting is permitted anytime.
 
Conditionally approved means that oysters and clams can be directly harvested except for the three days following a rainfall of an inch or greater in twenty-four hours. Harvesters are notified of conditional closings daily by an announcement broadcast by the Maryland Natural Resources Police made at 5, 6, and 7 a.m. on VHF radio band 14, by calling toll free 1-800-541-1210, or by visiting this web site for the daily advisory on conditionally approved shellfish areas.
 
Restricted means that no direct harvesting of oysters and clams is allowed at any time. Harvest from restricted areas (private leases and/or aquaculture only) is permitted by request for the purpose of natural cleansing (relay). Request for relay of oysters or clams from restricted waters to approved waters must be made in writing to MDE in advance of possible relay dates. Relay can occur only outside of oyster season and when water temperatures are above 50ºF.
 
All of the waters lying within the confines of any marina are prohibited for the harvesting or storing of shellfish. Also, all waters lying adjacent to marina facilities located in shellfish waters of the State and capable of accommodating ten (10) or more vessels are restricted for the harvesting or storing of shellfish between May 1st and September 30th of each year. These restrictions will include that area beyond a marina facility based on the following table:
 
Number of Slips   Distance of Restriction Beyond Marina
11-50 100 feet
51-100 150 feet
101-150
 200 feet​
​151-200
​250 feet
​Greater than 200​
​250 feet
 
 
These areas will be reopened to shellfish harvesting each year between October 1st and April 30th. Any individual owning a marina facility may request a variance for the size of the zone described above in accordance with the marina policy adopted by the Department on August 10, 1987. Anyone desiring additional information concerning this policy may call MDE, Water and Science Administration at (410) 537-3818.
 
Areas adjacent to sewage treatment outfalls are classified as prohibited as required under the National Shellfish Sanitation Program. Prohibited means that the harvest of shellstock for any purpose is not permitted. These areas are included in the descriptions that follow and are noted as "Closed Safety Zone/ prohibited". The enforcement of these closed areas is same whether the area is classified as restricted or prohibited.​
 
In addition, near-shore areas (shallow waters up to approximately 200 feet from shore) may appear as approved on the map because of inadequate resolution. These waters may be unmonitored and therefore unclassified as well as unsuitable for harvesting until they are monitored and classified as restricted, conditionally approved, or approved. Interested persons should contact MDE to determine the classification of all near-shore waters.
 

Maryland Shellfish Conditional Closure Log and Map

 

​​Conditionally Approved Shellfish Harvesting Areas

Maryland participates in the National Shellfish Sanitation Program (NSSP) to protect public health and to assure oysters and clams are harvested from areas that are safe. The basic concept of the National Shellfish Sanitation Program (NSSP) is to control the safety of shellfish by preventing the harvest of shellstock from polluted harvest areas. Shellfish include oysters and clams and not crabs, shrimp or lobsters. MDE classifies all shellfish harvesting areas or growing areas as Approved, Conditionally Approved, or Restricted.

Conditionally approved means that oysters and clams can not be harvested for three days following a rainfall event of one inch or greater over 24 hours. All other times, they can be harvested.
 
Harvesters are notified of conditional closings daily by an announcement broadcast by the Maryland Natural Resources Police made at 5, 6, and 7 a.m. on VHF radio band 14, by calling toll free 1-800-541-1210, or by visiting the website below: 
 
 
Conditionally approved harvesting areas generally meet the bacteriological water quality criteria for classification as approved when certain definable conditions occurs. If these conditions are not met, water quality in the harvest area is generally of lesser quality. When the conditions causing the water quality to be of lesser quality can be predicted, a management plan can be established which will allow harvesting when the water quality meets the criteria for the approved classification. Harvest areas regulated under these management plans are placed in the conditionally approved classification. In Maryland, the predictable condition is rainfall.
 
The Maryland Department of the Environment has established a rainfall level greater than or equal to 1 inch in 24 hours as an adverse pollution condition. This determination was based on an investigation and extensive data analysis done in 1987. The results indicated that elevated fecal coliform levels occur following a 1 inch rainfall in some portions of some harvest areas. The source was determined to be non-point source runoff which could not be traced to any source with public health significance. Based on intensive data analysis, 3 days were found to be the maximum time necessary for water quality to return to approved area quality. The water quality in the conditionally managed area was found to meet the approved classification bacteriological standard often within 48 hours and always within 72 hours. Therefore, placement of the harvest areas in the conditionally approved classification in the closed status for 3 days following the occurrence of the adverse pollution condition was determined to be a sufficient restriction.​ 
 

Information about Shellfish Safety

 

​​Maryland Shellfish Harvesting Areas

Maryland's Chesapeake Bay waters have long been known for their plentiful shellfish. To protect this valuable resource and safeguard public health the Maryland Department of the Environment is responsible for regulating shellfish harvesting waters.

Shellfish include clams, oysters, and mussels. The term shellfish does not include crabs, lobsters, or shrimp. Shellfish are filter-feeding animals: they strain the surrounding water through their gills which trap and transfer food particles to their digestive tract. If the water is contaminated with disease-causing bacteria, the bacteria are also trapped and consumed as food. If shellfish are harvested from waters which the Department has restricted (closed) and eaten raw or partially cooked, they have the potential to make people sick. Therefore, it is mandatory for oysters and clams to be harvested from approved (open) shellfish waters only.
 
MDE's Water and Science Administration (WSA) is responsible for regulating shellfish harvesting waters. This effort has three parts: 1) identifying and eliminating pollution sources, 2) collecting water samples for bacteriological examination; and 3) examining shellstock samples for bacteriological contamination and chemical toxicants.
 
Sanitary Surveys
 
Maryland Department of the Environment’s (MDE) conducts sanitary surveys of each shellfish growing area prior to its approval as a source of shellfish for the consumer. The purpose of the sanitary survey is to identify and evaluate factors influencing the sanitary quality of a shellfish growing area. These factors may include sources of potential and actual pollution (failing septic systems, animal wastes from agricultural properties, wastewater treatment plants, industrial waste, surface-runoff from polluted areas), bacterial quality of the water and shellfish, hydrographic characteristics of shellfish growing areas, and general land-use patterns.
 
Data gathered during the sanitary survey are used to evaluate the shellfish growing area and to determine whether a health risk exists. If no health risk is apparent, the area remains open to shellfish harvesting. When the data indicates a health risk, the area is restricted to the harvesting of shellfish. Through the efforts of this extensive program, Maryland has enjoyed an excellent reputation as a source of safe and wholesome shellfish products to seafood lovers throughout the nation and the world.

Maryland's Shellfish Harvesting and Closure Area Maps

The map show the Maryland Department of the Environment’s (MDE) classification status of oyster & clam harvesting waters. The map depicts the classification of shellfish growing waters of the State as restricted, conditionally approved, approved, or prohibited/Closed Safety Zone. A current detailed description of MDE's shellfish harvesting waters can be viewed by clicking on the link below:
 

The maps also show oyster sanctuaries established by the Department of Natural Resources (DNR). Sanctuaries are areas which are closed to oyster harvest and often contain oyster restoration projects to help enhance oyster populations for their environmental benefits. These areas are permanent closures. Sanctuaries established prior to 2010 are also closed to clam harvest.​
 

Interstate Shellfish Sanitation Conference (ISSC) and the National Shellfish Sanitation Program (NSSP)

 

​Because shellfish harvested from polluted water may cause human illness, the sanitary control of the shellfish industry is necessary. Maryland is a member of the Interstate Shellfish Sanitation Conference (ISSC), a voluntary, cooperative association of states, the shellfish industry, U.S. Food and Drug Administration (FDA), National Oceanic and Atmospheric Administration (NOAA), and Environmental Protection Agency (EPA). State responsibilities include adopting laws and regulations for the sanitary control of shellfish and the shellfish industry, formulating comprehensive shellfish harvesting area surveys and adopting control measures to ensure that shellfish are grown, harvested and processed in a safe and sanitary manner. FDA reviews methods for shellfish sanitation inlcuding for classification and management of shellfish areas proposed by the ISSC, and incorporates those methods consistent with standard health practice into the National Shellfish Sanitation Program (NSSP) Model Ordinance. FDA is also responsible for the audit of each state shellfish control program to determine conformity with the NSSP standards and guidelines. NOAA and EPA provide technical assistance and comment to the ISSC. The shellfish industry responsibilities include participation in the ISSC Conference, meeting the requirements of the NSSP Model Ordinance. These responsibilities include obtaining shellfish from safe sources, maintaining sanitary operating conditions and making records available that document location of harvest and sale of all shellfish. FDA, MDE and the shellfish industry fulfill their responsibilities to a high degree, thus ensuring shellfish harvested in Maryland are safe and wholesome. 

In Maryland, responsibility for the sanitary control of the shellfish industry is shared by three state agencies: the Department of the Environment (MDE), the Maryland Department of Health (MDH), and the Department of Natural Resources (DNR). MDE is responsible for identifying and eliminating pollution sources affecting Maryland's shellfish harvesting waters, as well as classifying shellfish harvesting waters so that shellfish harvested are safe for human consumption. MDH is responsible for any food control measures necessary to ensure that shellfish are harvested, processed, packaged, and transported under sanitary conditions. MDH also regulates shellfish dealers to assure compliance with the required sanitary standards. MDH Laboratories Administration analyzes water samples collected by MDE and samples collected as part of foodborne illness investigations. DNR is responsible for managing the fishery, enforcing sanitary harvesting practices and harvest restrictions, posting areas restricted to shellfish harvesting and for patrolling/enforcing these areas to prevent illegal harvesting.

 

NSSP/MDE Standard

Approved: (direct harvesting permitted)
Median <14 MPN/100ml 90th Percentile <49

Conditionally Approved (direct harvesting permitted only as outlined under heading Shellfish Water Classification below):
For conditionally approved Median <14 MPN/100 ml and no more than 10% can exceed 49 when the area is in the open status.

Restricted: (relay required)
Median <88 MPN/100ml 90th Percentile <300

Prohibited: (no growing or harvest permitted)
Closed Safety Zone for wastewater treatment facilities, Median >88 MPN/100ml 90th Percentile >300 or an area that has a high risk for human pathogens to be present.​

 

Maryland Lease Holders Guide for Shellfish Relay

 

​​Relay of Shellfish from Restricted Shellfish Waters to Approved Shellfish Waters

Documented research and studies with Eastern Oysters grown on natural bars have demonstrated that when the oysters are transplanted from moderately polluted to clean environments they will naturally attenuate accumulated indicator bacteria and associated pathogens over a 14-day period if environmental conditions are favorable for active filtering and feeding by the oysters.

Relay can only occur on shellfish leases where water temperatures are above 50°F. Generally during the months between April and August. ​ 
 
 

Maryland Shellfish Dealers Guide for Wet Storage of Market Size Shellfish

 

Acronyms

MDE- Maryland Department of Environment
MDH – Maryland Department of Health
DNR- Department of Natural Resources
NSSP- National Shellfish Sanitation Program
COMAR- Code of Maryland Regulation

General Requirements for Wet Storage 

This guide is for obtaining and maintaining a wet storage authorization\permit. Detailed information regarding wet storage can be found in the current edition of the NSSP Guide for the Control of Molluscan Shellfish, Chapter VII Wet Storage in Approved and Conditionally Approved Growing Areas.
 
The NSSP Guide is incorporated by reference in COMAR 10.15.07.01. Only certified dealers can apply and be authorized for wet storage. MDE is responsible for assuring that the water quality in the growing area used for this activity will meet the approved or conditionally approved classification and is the state agency that issues the authorization for wet storage. MDH is responsible for assuring that the applicant is currently a certified dealer and determines that the applicant has satisfactorily described or provided examples for lot identification, record keeping, and tagging that meet NSSP requirements. DNR is responsible for assuring that the applicant has a valid lease in the location the where wet storage is proposed and that the gear used on the lease is authorized.
 
Wet Storage in Natural Bodies of Water or Land Based Natural Water Flow-through Systems
 
Wet storage means the storage, by a dealer, of market size oysters or clams from growing areas in the approved classification or in the open status of the conditionally approved classification in containers or floats in natural bodies of water or in tanks containing natural seawater at any permitted land-based activity or facility.​
 
The applicant must be a MDH certified shellfish dealer and have a valid lease or authorization for in-water structures or gear with DNR. Wet storage in natural bodies of water or flow through systems on land shall not treat the water used for wet storage. For wet storage tanks with flow through systems on land utilizing adjacent natural waters, no additional permits from MDE are required for water appropriation or discharge. Structures used for wet storage and placed in the critical area or tidal waters may require additional federal, state, or local permits. 
  • Once a dealer fills out an application and submits the completed application to MDE, MDE will notify and share the application with MDH and DNR for review. The applicant must allow MDE, MDH or DNR access to the site for field review if necessary. Following a review of the application the applicant may be contacted for further clarification as needed.
  • MDE will review the growing area classification for all wet storage sites. If the applicant proposes a wet storage site near to shore or adjacent to existing docks or piers, MDE may determine that additional monitoring is needed to assure that the waters meet NSSP criteria. MDH and DNR notify MDE that the application meets or does not meet their requirements.
  • Land based flow through systems must also meet applicable local, state and federal regulations.
  • Flow through systems may only use waters from approved or conditionally approved growing areas and are not authorized to treat the water from the growing area.
  • When all three Departments are satisfied that the NSSP requirements are met the proposed wet storage activity can be authorized, a Wet Storage Authorization is issued by MDE. The certified dealer and the location is listed in the Interstate Certified Shellfish Shippers List (ICSSL) as “WS” by MDH, and a “WS” designation is added to their Food Processing Plant license number.
Once a wet storage activity is authorized by MDE: 
  • MDE conducts annual inspections of the wet storage site to assure that the there are no pollution sources that could have a negative impact on the water quality at the wet storage site or the waters used for land based flow through systems.
  • MDH conducts inspections of the wet storage site for proper product handling, lot identification, tagging, and shipping (trace back) records at least two times a year.
  • DNR conducts annual inspections to ensure that the gear used in the wet storage activity is authorized for use on the lease.
  • At any time, MDE may revoke this authorization if there is a downgrade in water quality which would cause the reclassification of these waters or if the requirements of the National Shellfish Sanitation Program and your lease agreement are not met.

Any proposed changes or alterations to the wet storage site (use different gear, addition of containers, expansion of the area for wet storage, etc.) must be re-approved or reauthorized prior to making the changes or alterations. An application detailing the changes must be submitted to MDE.

Application for Wet Storage in Natural Bodies of Water or Natural Water Based Flow-though Systems

The following information must be included on the application:

  1. Name, address, telephone number, email address (if available), MDH dealer certification number, DNR Shellfish Lease Number, and a list of all gear to be used on the lease (as authorized by the DNR shellfish lease agreement and the US Army Corps of Engineers permit). Application includes where the shellfish will come from.
  2. A chart indicating the exact location of storage sites and floats or other in water gear using latitude/longitude. If applicable, provide the exact location of the intake pipe/structure for land based or pier flow through systems.
  3. A physical description, diagram or photograph of the design of the wet storage structure or system.
  4. A written standard operating procedure (SOP) which includes:
    1. A description of the purpose for the wet storage operation (i.e. holding, conditioning, or increasing salt content) and any species-specific physiological factors that may affect design criteria.
    2. How the product is handled prior to wet storage,
    3. How product is tagged or identified during wet storage and,
    4. How product is handled and tagged when it comes out of wet storage.
  5. Flow through systems using tanks on land and natural waters, may require referral to MDH Center for Facility Process and Review for evaluation.

Wet Storage in Land-based Re-circulating Systems

Wet storage means the storage, by a dealer, of market size oysters or clams from growing areas in the approved classification or in the open status of the conditionally approved classification in tanks containing synthetic seawater at any permitted land-based facility.
 
Prior to construction or remodeling of a re-circulating system, a wet storage application must be submitted to MDE. A detailed plan and written operating procedures are required as part of the application. The application is referred to MDH Center for Facility Process and Review for evaluation and is also sent to DNR for review. 
  • The applicant will be contacted by MDH for any additional information required for the Facility Process Review to be completed.
  • The applicant must allow MDE, MDH or DNR access to the site for field review if necessary.
  • Once the review is completed and the application is approved by MDH, the re-circulation system may be authorized by MDE and construction may begin. Any changes to the plan must be approved by MDH prior to making the change. Any proposed construction and disposal of waste must also meet applicable local, state and federal regulations.
Once a re-circulating wet storage activity is authorized by MDE:
  • A study is required to demonstrate that disinfection for the re-circulating system can consistently produce water that tests negative for the coliform group.
  • Routine sampling by MDH and testing by a certified lab is required at least weekly or as determined by MDH.
  • MDH conducts inspections of the wet storage site for proper operation of the system, proper handling of shellstock, lot identification, tagging, and shipping (trace back) records at least two times a year.
  • When all three Departments are satisfied that the NSSP requirements are met, an approval is sent by the MDH Center for Facility and Process review, the certified dealer and location is listed in the ICSSL as “WS” and the designation is added to their Food Processing Plant license number.
  • At any time, MDE may revoke this authorization if the requirements of the NSSP are not met or upon recommendation of MDH inspectors.
 
Application for Wet Storage in Land-based Re-circulating Systems
 
The following information must be submitted to the department: 
  1. Name, address, telephone number, email address (if available), MDH dealer certification number. Source water shall not be from a growing area.
  2. Onshore facilities must submit a map indicating the location of the facility and source water used for wet storage.
  3. A physical description, diagram or photograph of the design of the wet storage structure or system.
  4. Provide details of any water treatment system.
  5. Final plans for construction or remodeling of onshore wet storage facilities shall be reviewed and approved by the MDH prior to commencing construction.
  6. Details of the plan, including the design, source and quantity of process water to be used for wet storage, and details of any process water (disinfection) treatment.
  7. Final plans and operating procedures that show how the system will meet all the requirements for wet storage in the NSSP.
  8. The application also includes:
    1. A description of the purpose for the wet storage operation (i.e. holding conditioning, or increasing salt content) and any species-specific physiological factors that may affect design criteria.
    2. A plan and details for monitoring the sanitary quality of the process water.
    3. The plan must include details as required in Chapter VII of the NSSP for Operation Specifications and Source Water,
    4. How product is handled prior to wet storage,
    5. How product is tagged and lots identified during wet storage and,
    6. How product is handled and tagged when it comes out of wet storage.
  9. Any proposed construction must also meet applicable local, state and federal regulations and disposal of waste must also meet local, state, and federal regulations.
Applications are submitted to MDE
By Mail to: MDE, Water and Science Administration, Public Health Section, Montgomery Park, 1800 Washington Blvd. Baltimore, MD 21230
Or by Fax: 410 537 3998
 
Download these Instructions and Application
 

Fact Sheets

Contact Information

 

For more information concerning shellfish harvesting, contact MDE's Water and Science Administration(WSA) at (410) 537-3873 or the Natural Resources Police at (410) 260-8880. For interstate shellfish sanitation information, visit http://www.issc.org

 

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Maryland Department of the Environment
1800 Washington Blvd
Baltimore, MD 21230