Responses of marine primary producers to interactions between ocean acidification, solar radiation, and warming
Year: 2012
Type: article
Abstract: Anthropogenic CO 2 is accumulating in the atmosphere and trapping reflected infrared radiation, resulting in warming of both terrestrial and ocean ecosystems.At the same time, the dissolution of CO 2 into seawater is increasing surface ocean acidity, a process known as ocean acidification.Effects of ocean acidification on marine primary producers have been documented to be stimulative, inhibitive, or neutral.Elevated CO 2 and reduced pH levels can interact with solar radiation, which fluctuates over different time scales from limiting to saturating or even stressful levels, to bring about synergistic, antagonistic, or balanced effects on marine primary producers at different depths or under changing weather conditions.However, shoaling of the upper mixed layer (enhanced stratification) due to ocean warming and freshening (rain, ice melting) can lead to additional photosynthetically active radiation (PAR) and ultraviolet (UV) exposure, which can have both benefits and costs to photosynthetic organisms.Elevated CO 2 concentrations under low or moderate levels of PAR have been shown to enhance photosynthesis or growth of both phytoplankton and macroalgae; excessive levels of PAR, however, can lead to additional inhibition of photosynthesis or growth under elevated CO 2 , and addition of UV radiation (280 to 400 nm) can increase or down-regulate such inhibition, since solar UV-B (280 to 315 nm) radiation often harms algal cells, while UV-A (315 to 400 nm) at moderate levels stimulates photosynthetic carbon fixation in both phytoplankton and macroalgae.In view of warming effects, increased temperatures have been shown to enhance photorepair of UV-damaged molecules, though it simultaneously enhances respiratory carbon loss.The net effects of ocean acidification on marine primary producers are therefore largely dependent on the photobiological conditions (light limitation, light or UV stress), as well as interactions with rising temperature and other variables such as altered nutrient availability.Hence, feedbacks between changing carbonate chemistry and solar radiation across the entire spectrum present complications to interpret and understand ocean acidification effects based on single-factor experiments.
Source: Marine Ecology Progress Series
DOI: 10.3354/meps10043
Authors: K Gao, EW Helbling, DP Häder, DA Hutchins
Language: English
Subfield: Oceanography
Field: Earth and Planetary Sciences
Domain: Physical Sciences
Open Access status: bronze
Awards: Experimental studies to understand and evaluate acclimation of marine plankton assemblages to increased CO2 and temperature., 海洋酸化对南海藻类固碳作用的影响：耦合效应与机制, G3114617964, G4125302545, Collaborative Research: Synergistic Effects of Iron, Carbon Dioxide and Temperature on the Fate of Nitrate: Implications for Future Changes in Export Production in the Southern Oce, G7273298922, G7885607733, G8305258720
OpenAlex ID: W2035891073