Assertion: bay oyster | /r/HasProperty | sampled for presence of msx
Facets:
value: for mortality along a salinity gradient
type: PURPOSE
value: since 1959
type: TEMPORAL
Source sentences:
text: Since 1959, native Delawere Bay oysters have been sampled for presence of MSX and for mortality along a salinity gradient that ranges at mid-tide and mean river flow from 20 to 23 ppt on the lower bay planted grounds, and from 9 to 18 ppt on the upper bay seed beds.