Controversies in Aquatic Sciences

The aquatic sciences have their share of scientific controversies. In some cases the controversy is the classic situation of economic benefit versus environmental protection; in other cases it involves “genuine” scientific debate over uncertainties of the science or debate over what management option is optimal. This chapter discusses two pollution cases that pit scientists from universities or government agencies against those supported by the industry responsible for the pollution. Additional controversies that are also discussed are a disagreement over management options for shoreline protection, and a scientific disagreement over uncertainties in data on fish populations, which is usually the reason for controversies over fisheries. Controversies over effects of pollution often focus on how much (what concentration) of a chemical is needed to produce a certain harmful effect. Chemical companies tend to argue that levels of a chemical found in the environment are too low to cause problems, while environmentalists typically contend that lower levels can be harmful. One chemical about which there is sometimes controversy is oil. In the case of oil spills, debate commonly centers on how long the effects of pollution last. Oil degrades over time, resulting in less oil in the environment. The critical issue here is: When does this degradation reach a point where spilled oil is no longer harmful? Oil is a complex combination of various hydrocarbons that generally floats on water, although some lighter-weight components (the water-soluble fraction) dissolve. Weathering is a process that takes place in the air and water, in which the lightweight components evaporate, thus leaving the heavier components (e.g., tar), which have traditionally been viewed as less toxic. When oil comes into shallow water and marshes, it can coat and smother resident communities. It can sink below the surface of beaches and marshes and remain there for many years. Oil in marsh sediments undergoes some microbial breakdown but very slowly. Effects of a small oil spill (190,000 gallons of number 2 fuel oil) in Falmouth, Massachusetts, in the late 1960s lasted for over a decade, according to Sanders et al. (1980).