The Mississippi River Delta Basin comprises approximately 521,000 acres of land and shallow estuarine water area in the active Mississippi River delta. About 40% of the coastal wetlands in the lower 48 states are found in the Mississippi River Delta. 83% of this area, or 420,000 acres, is open water. Coastal marshes
make up approximately 61,650 acres or about 61% of the total land area and 81% of this marsh is fresh, 17% is intermediate, and 2% is brackish-saline. Off the
Louisiana coast, in the Gulf of Mexico, scientist are monitoring one of the largest dead zones in the world.
This area is a major source of resources for the seafood industry, supplying 66% of harvested oysters and 16% of commercial fish. Consequently, if the hypoxic
zone continues or worsens, fishermen and coastal state economies will be greatly impacted. Consider the tolerance of oysters as noted in the data table and
reflect on the dissolved oxygen data compiled by NOAA. What DOK conclusion can be reached with regard to the survival of the oysters normal harvested in
this area?
Α.
The entire area mapped by NOAA would be detrimental to oyster survival
B.
At least half the area is detrimental to oyster survival due to DO levels
C.
The hypoxic area detrimental to oyster survival is small and could be avoided.
D.
Only the western 25% of the area would be detrimental to oysters as the DO is <2.