TITLE:        Overview of Marine Biotic Responses to Ozone Depletion
AUTHOR:       Raymond C. Smith
DATE:         25-26 March 1996
PLACE:        1996 International Whaling Commission (IWC) Symposium on
	      Climate Change and Cetaceans, Turtle Bay Hilton, Oahu,
	      Hawaii [Talk might be abstract; is in ucmbo talks and ucmbo
	      abs at the moment]

Abstract
It is now widely documented that reduced ozone will result in increased
levels of ultraviolet (UV) radiation, especially UV-B (280-320nm),
incident at the surface of the earth.  There is considerable evidence that 
ultraviolet radiation (UV) can cause biological damage at the molecular, 
cellular, population and community levels and there is increasing evidence 
that these higher levels of UV-B radiation may be detrimental to various 
forms of marine life in the upper layers of the ocean.  With respect to 
aquatic ecosystems, we also know that this biologically-damaging 
mid-ultraviolet radiation can penetrate to ecologically-significant depths 
in marine and freshwater systems.  This knowledge, plus the dramatic 
decline in stratospheric ozone over the Antarctic continent each spring, 
now known to be caused by anthropogenically released chemicals, has 
resulted in a number of recent reviews and reports.  In particular, the 
United Nations Environmental Program (UNEP) has provided recent updates 
(UNEP, 1989, 1991) with respect to the effects of ozone depletion on 
aquatic ecosystems and have concluded that "UV-B radiation in aquatic 
systems: 1) affects adaptive strategies (e.g., motility, orientation);
2) impairs important physiological functions (e.g., photosynthesis and
enzymatic reactions); and 3) threatens marine organisms during their 
developmental stages (e.g., the young of finfish, shrimp larvae, crab 
larvae)".  Possible consequences to aquatic systems include: reduced 
biomass production; changes in species composition and biodiversity;
and alterations of aquatic ecosystems and biogeochemical cycles associated
with the above changes.  Consensus is building toward the view that current 
levels of UV play a major role as an ecological determinant, influencing 
both survival and distribution, and are thus deserving of increased study 
independent of ozone-related UV-B increases.  On the other hand, there 
remains considerable controversy with respect to how laboratory and field 
results can be properly extrapolated to longer time and larger spatial 
scales and this problem is amplified by the exacting dosimetry required 
for quantitative results.  At the ecosystem level there are few, if any, 
convincing data with respect to effects of ozone-related UV-B increases, 
there is considerable uncertainty, little consensus, and much work remains.