Whither "biological effects monitoring"?

The term "pollution" implies biological effects, but until fairly recently, the only readily measurable biological end point was death; while this may be adequate to assess "end-of-pipe" water quality through LC50 determinations, it is not a useful measurement for receiving waters. During the last 20 years, many sublethal bioassays have been proposed or developed for use in marine environments, and several of these have been evaluated during collaborative studies by ICES and other intergovernmental organizations. A few have emerged as being consistently successful and are now used routinely to complement conventional assessments of marine pollution by chemical analyses. These bioassays range from biochemical measurements (such as hcpatic mono-oxygenase induction or acetylcholinesterase inhibition) through whole organism changes (e.g., oyster embryo bioassays, measurements o f "scope for growth") to measurements of (usually benthic) community structure. Some applications of these will be discussed in detail. Generally, the biochemical bioassays tend to be specific for a limited suite of contaminants, usually of similar chemical structures, and also tend to anticipate possible effects at higher levels of biological organization; at the other extreme, community structure measurements tend to be non-specific, and are retrospective in the sense that they show whether or not significant ecological changes have taken place. "Biological effects monitoring" approaches like these are not likely to replace conventional chemical analyses for regulatory purposes in the near future, but will probably be used increasingly to complement analytical chemistry.