Year

2005

Degree Name

Master of Science

Department

Department of Biological Sciences

Abstract

The destruction of the stratospheric ozone layer due to the anthropogenic production of ozone-depleting substances has led to the increased transmission of harmful ultraviolet-B radiation (280-320 nm) to the surface of the earth. Although exposure to ultraviolet radiation (UVR) is shown to be directly harmful to numerous marine species, less is known about the impacts of UVR at the community-level. To investigate the ecological effects of ambient solar UVR on macrobenthic assemblages in shallow-water marine environments, field experiments were used near Casey Station, East Antarctica and Wollonging, NSW, Australia. In both locations, experiments were done in the shallow subtidal zone using experimental panels and UV cut-off filters. To allow for maximum levels of UVR, experiments were done during the Austral summer. To test whether current levels of ambient UVR had any effect on macrobenthic assemblages developed in situ, experimental panels were placed under four different irradiation treatments (no UVR, transmits PAR only; no UVB, transmits PAR + UVA; an acrylic procedural control, transmits PAR -i- UVA -i- UVB; and a no-filter control, transmits PAR -I- UVA -I- UVB) and later collected for examination in the laboratory. The responses of the assemblages to the various treatments were determined by measuring diversity, total biomass, and community composition. Experimental panels in Antarctica were deployed between January and February 2001. After 46 d in the field, benthic marine diatoms dominated all the panels in all treatments. Up to 77 species of diatom were identified and recorded.

Share

COinS