Ağırbaş E. (Executive), Gedik K., Dizman S., Mutlu T., Şahin A., Fidan D.
TUBITAK Project, 2021 - 2023
Phytoplankton communities
constitute approximately 50% of global primary production on Earth, and nearly
all of the marine primary productivity. At the same time, they contribute to
modulating the total CO2 concentration and regulating the pH of the
ecosystem via photosynthesis. Due to the important global role of phytoplankton, monitoring their
biomass and estimation of the composition has major importance for
understanding the structure and dynamics of pelagic ecosystems
Atmospheric CO2
concentration has increased by around 33% over pre-industrial levels, with an
on-going annual increase of 0.4%. Prior to the industrial revolution, the
atmospheric CO2 concentration since the industrial
revolution increased from 280 ppm risen to 370 ppm, and according to
climate scenarios, the CO2 concentration is expected to increase to
700 ppm over the next 100 years. The increased atmospheric CO2 concentration in
the surface layers of the oceans and seas directly affects the carbonate
chemistry which has lowered pH by 0.1 units, from 8.21 to 8.10. About 25% of
anthropogenic CO2 emissions are absorbed by the ocean, generating
profound modifications of the ocean carbonate chemistry and referred to as
“ocean acidification” or “acidification”.
Environmental factors that change due to acidification lead to changes
in phytoplankton community structure and biomass, as well as changes in the
biogeochemical structure of the environment. On the other hand, anthropogenic
carbon dioxide (CO2) emissions are responsible for an important
increase in atmospheric CO2 partial pressure. The consequences of CO2
emissions are an increase in surface ocean temperature expected to rise by 2-4ºC
by the end of this century based on the current emission rates.
The purpose of this project is to investigate
the seasonal effect of CO2 enrichment (360 ppm, 600 ppm, and 760
ppm), and temperature changes (ambient, plus+3ºC) on the phytoplankton primary production and
community structure by a series of incubation experiments for the first time in
natural phytoplankton specimens along the South Eastern Black Sea ecosystem
which is extremely important for fisheries and under changing climatic
conditions. In addition, the primary production rates of phytoplankton size
classes (picophytoplankton, nanophytoplankton and microphytoplankton) will be
determined by using C-14 incubation experiments. Thus, with the
contribution of different size classes to primary production on a seasonal
scale, it will be possible to demonstrate that how primary production rates
will change depending on phytoplankton biomass, CO2 enrichment and
temperature changes. Moreover, the project
results will provide data for Turkey’s National Climate Change Adaptation
Strategy and Action Plan, and climate change, CO2 emissions and adaptation
to climate change in the Black Sea ecosystem within
the scope of the objectives of the 11th Development Plan.