DNR says it looks as if there could be a downturn in the 2008 harvest. Drought-like conditions, including more salt in the Chesapeake Bay waters, is causing diseases that can threaten oysters’ health. Rainfall was lower in 2006 and 2007, which means oysters harvested this year had a lower chance of surviving to maturity. The Maryland Watermen’s Association expects to charge $32 a wholesale bushel, two-dollars more than last year.