Marine Science

Marine Science

Senior Theses 2004

Corey J. Peloquin (2004). Evaluating techniques to promote seed germination for Florida native plants (Canavalia rosea, Sophora tomentosa var. truncata, and Zamia pumila).
Faculty advisor: Jeannine Lessmann

ABSTRACT

Anthropogenic increases of ozone depleting chemicals, such as chloroflourocarbons (CFCs) have led to an increase of ultraviolet radiation (UV) B (280-220 nm) reaching the earth's surface and transmitting to significant depths of the ocean. Algae are responsible for a significant portion of the world's oceanic oxygen and constitute an integral trophic level of ecosystem structure. Thus far, there have been no studies that have investigated the effects of increased DV -B on the reproductive unicells (gametes and zoospores). The biological effects of enhanced UV-B on the reproductive phases of Enteromorpha intestinalis were examined by the application of chlorophyll a fluorescence. The irradiances of 0, 50, 166, and 220 ยต Wcm-2 were used and. measurements were taken at 0, 10 and 60 minutes of UV-B exposure. The application of chlorophyll fluorescence can positively be used for the evaluation of UV-B induced photo inhibition within the zoospores and gametes of E. intestinalis. Dose-response curves can be extrapolated for both phases of the reproductive cycle, suggesting that they respond in a predictable manner. The zoospores appear to be less sensitive to UV-B radiation than the gametes within the parameters of Fv/From, Fv, and Fo. It appears that genetic diversity could be compromised in a high irradiance event. The reproductive unicells are possibly more sensitive to UV-B radiation than the mature thalli. More attention must be spent on investigating the reproductive cycle of macro algae to completely understand the overall biological effects of UV-B on autotrophic species.

Student Research