Güneydoğu Karadeniz'de CO2 Zenginleştirmesinin ve Sıcaklık Değişimlerinin Fitoplankton Birincil Üretimi Üzerine Olan Mevsimsel Etkisinin Araştırılması


Ağırbaş E. (Executive), Gedik K., Dizman S., Mutlu T., Şahin A., Fidan D.

TUBITAK Project, 2021 - 2023

  • Project Type: TUBITAK Project
  • Begin Date: November 2021
  • End Date: November 2023

Project Abstract

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.