UV EFFECTS ON MARINE ORGANISMS 



JOHN T. HARDY 



Department of General Science 



Oregon State University 



Weniger Hall 355 



Corvallis, Oregon 97331-6505 



ABSTRACT: The marine environment covers 71% of the Earth's surface and is 

 important in the global cycling of carbon as well as many other elements. Also, 

 marine fisheries supply a major part of the diet for much of the world's 

 population. Stratospheric ozone depletion, especially at levels now occurring 

 during springtime over Antarctica, poses a real threat to important 

 biogeochemical cycles and biotic resources in the marine environment. 



Ultraviolet-B radiation (UV-B) penetrates to about 10% of the euphotic zone. In 

 pelagic ocean water this may exceed 20 meters in depth. Research has 

 demonstrated that enhanced UV-B radiation exposures, simulating realistic future 

 ozone depletions, can produce a number of detrimental effects on marine organisms 

 or communities. Responses include reductions in the growth and photosynthesis of 

 photoautotrophs (phytoplankton and seagrass), acute mortality, and reduced 

 fecundity in copepods, increased abnormalities in shellfish larvae, decreased 

 survival in shrimp and crab larvae, and inhibition of growth and induced lesions 

 in fish larvae. 



Despite the evident sensitivity of marine organisms to UV-B radiation, great 

 uncertainty remains in extrapolating from effects on individuals to those on the 

 population or community. These uncertainties arise from: 1) the difficulty in 

 defining the in situ exposure regime; 2) the presence of compensatory mechanisms 

 in the population; and 3) the occurrence of indirect (food web) effects. Given 

 this uncertainty, an overall assessment of the ecological effects of increasing 

 UV-B radiation in the marine environment is not currently possible. Dose- 

 response data is needed on the effects of UV-B radiation on plankton, 

 biogeochemial cycles, fish eggs and larvae, corals, and on mixed community 

 mesocosms. In many cases, basic habitat and population distribution data will be 

 needed to build predictive models. 



REFERENCES: 



Calkins, J., 1982. Some considerations on the ecological and evolutionary effects 

 of solar UV. In, The Role of Solar Ultraviolet Radiation in Marine Ecosystems 

 (J. Calkins, ed.j. Plenum Press, New York, pp. 685-689. 



Worrest, R.C., 1982. Review of literature concerning the impact of UV-B 

 radiation upon marine organisms. In, The Role of Solar Ultraviolet Radiation in 

 Marine Ecosystems (J. Calkins, ed.). Plenum Press, New York, pp. 429-457. 



Worrest, R.C. 1986. The effects of solar UV-B radiation on aquatic systems: an 



overview. In, Effects of Changes in Stratospheric Ozone and Global Climate Vol. 



1: Overview (J.G. Titus, ed.). Environmental protection Agency and United 

 Nations Environment Programme, pp. 175-191. 



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