|
This study evaluated the individual and combined impacts of temperature, pyrene,
and cadmium on the coastal diatom Thalassiosira weissflogii under conditions
representative of the Gulf of Guinea. In the individual stressor experiments, time,
rather than temperature or individual pollutants, was the primary factor influencing
growth parameters. Specifically, temperature modulated diatom growth with optimal
performance at 28 °C, while 24 °C and 32 °C conditions reduced cell density, chlorophyll-a
content, and dry biomass. On the other hand, pyrene significantly affected cell density and
dry biomass, while cadmium elicited minimal effects on all measured parameters. In combined
stressor experiments, the negative impacts of pyrene and cadmium combinations were more
exacerbated at 24 °C and 32 °C, whereas optimal thermal conditions (28 °C) provided partial
mitigation from exposure to stressors. These findings highlight the crucial role of temperature
in modulating the effects of pollutants on Thalassiosira weissflogii, with combined stress having
the greatest impact under non-optimal temperature conditions. Additionally, the study underscores
the temperature sensitivity of Thalassiosira weissflogii in tropical ecosystems and offers insights into
how the simultaneous stressors of rising ocean temperatures and increasing pollution may affect tropical
phytoplankton dynamics and primary productivity. Lastly, the study emphasizes the importance of incorporating
thermal thresholds into marine ecosystem models to more accurately predict shifts in coastal and oceanic
food webs under climate change scenarios.
|
University of Cape Coast