Effects of Increased CO₂and Temperature on the Growth of Four Diatom Species (Chaetoceros debilis, Chaetoceros didymus, Skeletonema costatum and Thalassiosira nordenskioeldii) in Laboratory Experiments

Abstract

We examined the combined impacts of future increases of CO2 and temperature on the growth of four marine diatoms (Skeletonema costatum, Chaetoceros debilis, Chaetoceros didymus, Thalassiosira nordenskioeldii). The four strains were incubated under four different conditions: present (pCO2: 400ppm, temperature: 20℃), acidification (pCO2: 1000ppm, temperature: 20℃), global warming (pCO2: 400ppm, temperature: 25℃), and greenhouse (pCO2: 1000ppm, temperature: 2 5℃) conditions. Under the condition of higher temperatures, growth of S. costatum was suppressed, while C. debilis showed enhanced growth. Both C. didymus and T. nodenskioldii showed similar growth rates under current and elevated temperature. None of the four species appeared affected in their cell growth by elevated CO2 concentrations. Chetoceros spp. showed increase of pH per unit fluorescence under elevated CO2 concentrations, but no difference in pH from that under current conditions was observed for either S. costatum or T. nodenskioeldii, implying that Chetoceros spp. can take up more CO2 per cell than the other two diatoms. Our results of cell growth and pH change per unit fluorescence suggest that both C. debilis and C. didymus are better adapted to future oceanic conditions of rising water temperature and CO2 than are S. costatum and T. nodenskioeldii.

Effects of Ocean Acidification on Marine Photosynthetic Organisms Under the Concurrent Influences of Warming, UV Radiation, and Deoxygenation

“…For example, in the picoplanktonic cyanobacterium Synechococcus, warming and OA together promote its growth, but they have no effects on Prochlorococcus (Fu et al, 2007). Similarly, simultaneous OA and warming by 4 • C promoted the growth of the diatom Skeletonema (Kremp et al, 2012), but had no obvious effects on Thalassiosira and Chaetoceros (Hyun et al, 2014). Under acidification and warming conditions, the growth rate and calcification of the coccolithophore Coccolithus decreased (Schlüter et al, 2014), and OA and warming together lowered the optimum growth temperature and maximum growth rate of E. huxleyi (Listmann et al, 2016).…”

An updated synthesis of the observed and projected impacts of climate change on the chemical, physical and biological processes in the oceans

“…Synergistic negative effects have been observed on the growth, survival, fitness, calcification and development of organisms (Padilla-Gamino et al, 2013;Vehmaa et al, 2013;Gaitán-Espitia et al, 2014;Gobler et al, 2014;Hyun et al, 2014;Mackenzie et al, 2014b;Madeira et al, 2014;Maugendre et al, 2014Roy et al, 2014;Schram et al, 2014;Rosa et al, 2014a,b;Schmidt et al, 2014a). In some cases, hypoxic conditions have been observed to mediate the negative effects of ocean acidification (Mukherjee et al, 2013).…”

Ocean Acidification and Warming Lead to Increased Growth and Altered Chloroplast Morphology in the Thermo-Tolerant Alga Symbiochlorum hainanensis

“…Laboratory studies have shown that the effects of the combined treatment of elevated temperature and acidification on the growth of marine algae are species specific ( Hyun et al, 2014 ; Gao et al, 2019 ). For example, the growth of the picoplanktonic cyanobacterium Synechococcus was promoted by the combined treatment, whereas elevated temperature and acidification had no effects on Prochlorococcus ( Fu et al, 2007 ).…”

“…For example, the growth of the picoplanktonic cyanobacterium Synechococcus was promoted by the combined treatment, whereas elevated temperature and acidification had no effects on Prochlorococcus ( Fu et al, 2007 ). Similarly, the combined treatment promoted the growth of the diatom Skeletonema ( Kremp et al, 2012 ), but it had no obvious effects on Thalassiosira and Chaetoceros ( Hyun et al, 2014 ). The growth of coccolithophore E. huxleyi was inhibited by the combined treatment ( Listmann et al, 2016 ).…”