BALTIMORE, MD (September 1, 2011) – The emergency closure to shellfish harvesting in Maryland waters issued last weekend in anticipation of Hurricane Irene expires Saturday, Sept. 3., for most areas.
The expiration of the temporary closure means that previous designations for areas that are approved or conditionally approved for shellfish harvesting will again apply effective Sunday, Sept. 4, with the exception of a portion of the Chesapeake Bay at the mouth of the Patapsco River affected by a sewage spill into the Patapsco River. The Patapsco River has been closed to shellfish harvesting since the 1960s.
“Maryland temporarily closed its waters to shellfish harvesting to prevent the potentially harmful effects of eating shellfish exposed to contaminated waters and to ensure that Maryland maintains its reputation for safe and wholesome seafood products,” said MDE Secretary Robert M. Summers. “Starting this weekend, people can again enjoy shellfish harvested from areas that are reopened for harvesting.”
Information on shellfish harvesting areas is available on the Maryland Department of the Environment’s website. These designations apply only to the harvesting of shellfish (oysters and clams); they do not apply to fishing or crabbing. Consumption advisories for recreationally caught fish and crabs can also be found on MDE’s website.
As Hurricane Irene approached Maryland, MDE determined that tidal flooding from the storm could affect septic systems, cause sewer systems to overflow, and create the potential for shellfish harvesting waters to be contaminated. Receding tides and large amounts of polluted stormwater runoff can also carry contaminants to waterways.
The emergency closure to shellfish harvesting in the Maryland portion of the Chesapeake Bay, including all tributaries, and Maryland’s coastal bays went into effect Sunday, Aug. 28, with a tentative expiration date of Sept. 3. MDE issued a similar, week-long emergency closure to shellfish harvesting in the Chesapeake Bay and its tributaries due to flooding caused by Tropical Storm Isabel in September 2003.
Irene did not cause the extent of tidal flooding that occurred during Isabel, but wastewater treatment facility owners from across the state notified MDE of bypasses at wastewater treatment plants, pumping station failures, and sewer overflows. Water sampling done Monday showed levels of bacteria at many locations to be elevated compared to previous sampling at those locations.
The emergency closure for most areas can be lifted because the sewage overflows – other than the sewage main break near the Patapsco River – were resolved, and because several tidal cycles naturally flushed waterways. The passage of time also allows shellfish to purge themselves of contaminants.
The commercial oyster season in Maryland does not begin until Oct. 1. The emergency closure affects, in addition to the harvesting of clams, the harvesting of oysters from leased beds and through aquaculture operations. Those oysters can normally be harvested throughout the year.
MDE received a report from Baltimore County of a break in a 54-inch sewer main at the Patapsco sewage pumping station east of Old Annapolis Road in Baltimore Highlands that occurred shortly before midnight, Sunday, August 28. The line carries an estimated 17 million gallons of sewage daily. Repairs on the broken line are continuing. Health officials in both Baltimore County and Anne Arundel County issued notices regarding water contact for a portion of the Patapsco River.
Due to that spill, MDE determined that a portion of the Chesapeake Bay, near the mouth of the Patapsco River and normally open to shellfish harvesting, will remain temporarily closed. The affected area is all of the shellfish harvesting waters of the Patapsco River and the Chesapeake Bay lying downstream of a line running in a northeasterly direction from Rock Point to North Point and west of a line running in a southeasterly direction from North Point to the Brewerton Eastern Extension Lighted Buoy 10, and then to Seven Foot Knoll Light to Craighill Channel Lighted Buoy 18, and then in a southwesterly direction to Craighill Channel Lighted Buoy 16 and then running east to the Craighill Entrance Channel RR (multiple light structure) then continuing east to a point of land near Shore End Downs Fishing Pier south of Pinehurst on the Anne Arundel County shore. Click here for a map of the area. The area was determined based on the tracking of sewage during a previous spill. No reopening date for shellfish harvesting has been determined for that area.
Shellfish are filter feeders with the ability to filter water and get food from microscopic organisms in the water. If the waters are polluted, this filtering process can concentrate disease-causing organisms associated with raw sewage and other sources, such as animal waste. Oysters and clams are often eaten raw or partially cooked and must come from waters that are not polluted.
MDE monitors bacteriological water quality and conducts pollution source surveys to determine which areas are safe for the harvesting of shellfish. The Department is required to close areas that do not meet the strict water quality standards for shellfish harvesting waters, and it has a longstanding policy to reopen areas to shellfish harvesting when water quality improves. These actions ensure that Maryland remains in compliance with National Shellfish Sanitation Program requirements.