Maryland’s Oyster Population Continues to Improve, Highest since 1985
Governor Martin O’Malley today announced good news regarding the State’s ongoing work to restore the Chesapeake Bay’s native oyster population. Results of Maryland’s 2013 Fall Oyster Survey indicate the oyster biomass index, a combined measure of oyster abundance and size, has more than doubled since 2010, reaching its highest point since this type of monitoring began in 1985.
“These survey results indicate that our multi-pronged strategy to restore our native oyster population is paying off,” said Governor O’Malley. “While this progress is noteworthy, it underscores the need to stay the course, reinforcing our commitment to protect our investment and rebuild this essential, iconic species.”
The upswing was driven by high oyster survival over the past few years as well as strong reproduction in 2010 and 2012. As a result, oyster harvests have increased, with watermen quickly reaching their daily catch limits during the early part of the season.
“Preliminary harvest reports for the past season have already surpassed 400,000 bushels – with a dockside value in excess of $13 million ─ the highest in at least 15 years,” said DNR Secretary Joe Gill. “Coupled with the survey results, we have reason to be cautiously optimistic a sustainable oyster population can once again play a vital role in the Bay’s ecosystem and Maryland’s economy.”
In one of the longest running such programs in the world, Maryland has monitored the status of the State’s oyster population through annual field surveys since 1939. The surveys track relative oyster population abundance, reproduction, disease and annual mortality rates, and offer a window into future population levels.
According to the survey, at 92 percent, oyster samples revealed the highest survival rate (the number of oysters found alive in a sample), since 1985 when these measurements began. The Maryland Oyster Biomass Index, a measure of the oyster population, was also the highest since 1985. Oyster reproduction was slightly above the 29-year midpoint, but was largely confined to the lower portion of the Bay.
Oyster diseases remain at relatively low levels. Dermo was below the long-term average for the eleventh consecutive year, with levels similar to 2012, but, continues to be widely distributed throughout Maryland waters. MSX increased slightly from the record-low levels of 2011 and 2012, but remains well below the long-term average.
Since 1994, the Chesapeake Bay oyster population has languished at less than one percent of historic levels. In 2011, researchers with the University of Maryland Center for Environmental Science concluded that Maryland’s oyster population was just 0.3 percent of its abundance in the early 1800s. This decline is attributed to heavy fishing pressure beginning in the late 1800s, oyster disease mortalities, and the depletion of oyster habitat. Over the past 30 years, the amount of suitable oyster habitat has declined 80 percent ─ from 200,000 acres down to 36,000 acres ─ and Maryland’s once renowned oyster harvest fell from about 1.5 million bushels a year to an average of 142,000.
Governor Martin O’Malley has made oyster restoration a priority of his Administration, this past fall announcing significant progress under his Oyster Restoration and Aquaculture Development Plan. Under the plan, the State and its partners increased Maryland’s network of oyster sanctuaries from 9 percent to 24 percent of remaining quality habitat, planted a national record 1.25 billion native spat in Maryland last year, increased areas open to leasing for oyster aquaculture and streamlined the permitting process, established a $3.9 million financial assistance program for aquaculture interests, and maintained 76 percent of the Bay’s remaining quality oyster habitat for a more targeted, sustainable and scientifically managed public oyster fishery. The plan also focused on stepping up enforcement and penalties to protect the State’s investment in oyster restoration.
Oyster populations in several large-scale sanctuaries have increased substantially over the past few years. Oysters are also increasing dramatically in the natural habitats they still occupy, however, these areas have declined greatly. Through carefully targeted restoration of degraded areas adjacent to (but not overlapping) functional reefs, the State is expanding the footprint of viable oyster habitat, which will ultimately result in expanded ecosystem services. Natural mortality rates within the sanctuaries were similar to adjacent harvest areas.
DNR is currently conducting a scientifically-driven, large-scale oyster restoration project on the Little Choptank. For more information on this project, visit dnr.state.md.us/fisheries/pdfs/LITTLE_CHOPTANK_FAQ.pdf
“Maryland’s oyster sanctuaries continue to provide oysters with a refuge from harvest pressure, enabling the re-establishment of oyster reefs and associated ecosystem services and allowing natural selection to foster disease resistance,” said DNR Fisheries Director Tom O’Connell. “Governor O’Malley’s 2015 capital budget included $7.3 million for restoration work in HarrisCreek and Little Choptank River sanctuaries, where restoration efforts are showing great promise.”