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In this paper, we demonstrated that ocean acidification (OA) had significant negative effects on the microscopic development of Saccharina japonica in a short-term exposure experiment under a range of light conditions. Under elevated CO2, the alga showed a significant reduction in meiospore germination, fecundity, and reproductive success. Larger female and male gametophytes were noted to occur under high CO2 conditions and high light magnified these positive effects.

Diatoms are often considered to be a single functional group, yet there is a great deal of morphological, genetic and ecological diversity within the class. How these differences will translate into species-specific responses to rapid changes in the ocean environment resulting from climate change and eutrophication is currently poorly understood.

Mg/Ca ratio paleothermometry in foraminifera is an important tool for the reconstruction and interpretation of past environments. However, existing Mg/Ca:temperature relationships for planktic species inhabiting mid- and high- latitude environments are limited by a lack of information about the development and impact of low-Mg/Ca ratio “crusts” and the influence of the carbonate system on Mg/Ca ratios in these groups.

Concerns about the impacts of ocean acidification on marine life have mostly focused on how reduced carbonate saturation affects calcifying organisms. Here, we show that levels of CO2-induced acidification that may be attained by 2100 could also have significant effects on marine organisms by reducing their aerobic capacity. The effects of temperature and acidification on oxygen consumption were tested in 2 species of coral reef fishes, Ostorhinchus doederleini and O. cyanosoma, from the Great Barrier Reef, Australia.

Ocean acidification and warming are expected to threaten the persistence of tropical coral reef ecosystems. As coral reefs face multiple stressors, the distribution and abundance of corals will depend on the successful dispersal and settlement of coral larvae under changing environmental conditions. To explore this scenario, we used metabolic rate, at holobiont and molecular levels, as an index for assessing the physiological plasticity of Pocillopora damicornis larvae from this site to conditions of ocean acidity and warming.

During mariculture period, maricultured macroalga Gracilaria lemaneiformis experienced seasonal temperature changes. In this study, we examine the effects of predicted ocean acidification on carbon and nitrogen accumulation and amino acids (AA) contents in G. lemaneiformis under different temperature levels. The results showed that G. lemaneiformis exhibited higher growth rates under high temperature conditions than under low temperature conditions, regardless of CO2 levels. Moreover, compared with low temperature, the culture conditions of high temperature enhanced N accumulation in G.

Diseases threaten the structure and function of marine ecosystems and are contributing to the global decline of coral reefs. We currently lack an understanding of how climate change stressors, such as ocean acidification (OA) and warming, may simultaneously affect coral reef disease dynamics, particularly diseases threatening key reef-building organisms, for example crustose coralline algae (CCA).

By the end of this century, anthropogenic carbon dioxide (CO2) emissions are expected to decrease the surface ocean pH by as much as 0.3 unit. At the same time, the ocean is expected to warm with an associated expansion of the oxygen minimum layer (OML). Thus, there is a growing demand to understand the response of the marine biota to these global changes. We show that ocean acidification will substantially depress metabolic rates (31%) and activity levels (45%) in the jumbo squid, Dosidicus gigas, a top predator in the Eastern Pacific. This effect is exacerbated by high temperature.

Anthropogenic CO2 is causing warming and ocean acidification. Coral reefs are being severely impacted, yet confusion lingers regarding how reefs will respond to these stressors over this century. Since the 1982-83 El Niño-Southern Oscillation warming event, the persistence of reefs around the Galápagos Islands has differed across an acidification gradient. Reefs disappeared where pH \textless 8.0 and aragonite saturation state ($Ømega$arag) ≤ 3 and have not recovered, whereas one reef has persisted where pH \textgreater 8.0 and $Ømega$arag \textgreater 3.

Human-induced ocean acidification and warming alter seawater carbonate chemistry reducing the calcification of reef-building crustose coralline algae (CCA), which has implications for reef stability. However, due to the presence of multiple carbonate minerals with different solubilities in seawater, the algal mineralogical responses to changes in carbonate chemistry are poorly understood. Here we demonstrate a 200% increase in dolomite concentration in living CCA under greenhouse conditions of high pCO2 (1,225 muatm) and warming (30 degrees C).

As global ocean change progresses, reef-building corals and their early life history stages will rely on physiological plasticity to tolerate new environmental conditions. Larvae from brooding coral species contain algal symbionts upon release, which assist with the energy requirements of dispersal and metamorphosis. Global ocean change threatens the success of larval dispersal and settlement by challenging the performance of the larvae and of the symbiosis.

The physiological response to individual and combined stressors of elevated temperature and pCO2 were measured over a 24-day period in four Pacific corals and their respective symbionts (Acropora millepora/Symbiodinium C21a, Pocillopora damicornis/Symbiodinium C1c-d-t, Montipora monasteriata/Symbiodinium C15, and Turbinaria reniformis/Symbiodinium trenchii). Multivariate analyses indicated that elevated temperature played a greater role in altering physiological response, with the greatest degree of change occurring within M. monasteriata and T. reniformis.

Two of the major threats to coral reefs are increasing sea surface temperature and ocean acidification, both of which result from rising concentrations of atmospheric carbon dioxide (CO2). Recent evidence suggests that both increased water temperature and elevated levels of dissolved CO2 can change the behaviors of fishes in ways that reduce individual fitness, however the interacting effects of these variables are unknown.