Abstract:
Marine phytoplankton is responsible for sequestering an estimated 104 Giga ton carbon
per year which is approximately half the photosynthetic production on Earth.
Phytoplankton mostly occupies the water surface or photic zone where ultraviolet-A
radiation is highest. Scientific concern over ozone depletion in the upper atmosphere has
prompted extensive efforts to assess the potential damage to life on Earth due to
increased levels of UV radiation. Therefore, 7 species of natural phytoplankton
population from University Malaysia Terengganu's beach and 2 species of monoalgal
culture have been used to determine the effect of ultraviolet-A radiation on its growth
rate, growth dynamic and cell division time. Results showed that there is no significant
difference (p>0.05) in the growth dynamic except for Gymnodinium sp. However, there
is slight effect of ultraviolet-A on their growth rate and cell division time where species
exposed to ultraviolet-A have lower growth rates and higher cell divison time compared
to species exposed to non ultraviolet-A radiation. Overall, the results indicate that
ultraviolet-A radiation does not have acute effect on natural phytoplankton population.
