Difficulties in Predicting the Consequences of Water-Soluble Pollutant Input into the Marine Environment

Abstract

An increasing amount of water-soluble toxicants are entering the world ocean yearly. Effects of such pollutants on the survival of marine organisms are often dramatic, and readily quantifiable. Sublethal pollutant effects are more difficult to detect, but are likely to have substantial long-term impact on marine ecosystems. Of particular importance are responses which interfere with normal reproductive patterns. Various pollutants are known to interfere with gamete formation, fertilization, and embryonic and larval development (including morphological, behavioral and physiological aspects). Such responses will likely alter normal patterns of dispersal and recruitment, and disrupt normal patterns of ecological interaction both within and among species. Predicting the long-term consequences of continued input of particular pollutants in nature is made difficult by 1) the lack of a standardized experimental protocol in laboratory bioassays and the difficulty of standardizing such bioassays, 2) variability of, and the likelihood of complex interactions among, environmental variables, including temperature, salinity, and other pollutants, 3) temporal shifts in the physiological status of organisms exposed to pollutants, 4) limited understanding of how various toxicants enter biological systems, 5) limited understanding of the biochemical, developmental, and physiological mechanisms through which different pollutants exert their toxic effects, and 6) limited understanding of the complex ecological interactions among marine organisms.