How do scientists determine if there are harmful PAHs in seafood?
Crude oils differ in how they behave in the environment and how they affect fish and shellfish. Where oil is spilled also makes a difference. After a spill, the first thing scientists do is evaluate the type of oil spilled and the location of the spill to determine which fish or shellfish species are most likely to be exposed to the oil. • Oils that mix with the water and spills that occur in deep water are more likely to affect finfish. • Heavier oils that strand on shorelines are more likely to affect shellfish, especially bivalve molluscs like mussels. If scientists determine that fish or shellfish may be exposed to the oil, the next step is to collect seafood samples from the spill area and measure levels of PAHs in their tissues. Fish and shellfish are also evaluated for taint. Scientists collect seafood samples from nearby areas not affected by the spill to determine the “background” levels of PAHs normally found in seafood in that area. How do scientists determine what levels of
