Depletion of oysters Chesapeake Bay

oyster boats @ war off maryland shore (1886 wood engraving). regulation of oyster beds in virginia , maryland has existed since 19th century.

while bay s salinity ideal oysters , oyster fishery @ 1 time bay s commercially viable, population has in last fifty years been devastated. maryland once had 200,000 acres (810 km) of oyster reefs. today has 36,000. has been estimated in pre-colonial times, oysters filter entirety of bay in 3.3 days; 1988 time had increased 325 days. harvest s gross value decreased 88% 1982 2007. 1 report suggested bay had fewer oysters in 2008 25 years earlier.

a cluster of oysters grown in sanctuary

the primary problem overharvesting. lax government regulations allow license remove oysters state-owned beds, , although limits set, not enforced. overharvesting of oysters has made difficult them reproduce, requires close proximity 1 another. second cause oyster depletion drastic increase in human population caused sharp increase in pollution flowing bay. bay s oyster industry has suffered 2 diseases: msx , dermo.

the depletion of oysters has had particularly harmful effect on quality of bay. oysters serve natural water filters, , decline has further reduced water quality of bay. water once clear meters turbid wader may lose sight of feet while knees still dry.

efforts of federal, state , local governments, working in partnership through chesapeake bay program, , chesapeake bay foundation , other nonprofit environmental groups, restore or @ least maintain current water quality have had mixed results. 1 particular obstacle cleaning bay of polluting substances arise far upstream in tributaries lying within states far removed bay. despite state of maryland spending on $100 million restore bay, conditions have continued grow worse. twenty years ago, bay supported on 6 thousand oystermen. there fewer 500.

efforts repopulate bay via hatcheries have been carried out group called oyster recovery partnership, success. placed 6 million oysters on 8 acres (32,000 m) of trent hall sanctuary. scientists virginia institute of marine science @ college of william & mary claim experimental reefs created in 2004 house 180 million native oysters, crassostrea virginica, far fewer billions once existed.