An enormous amount of anthropogenic carbon dioxide (CO2) has been dissolved into the ocean, leading to a lower pH and changes in the chemical properties of seawater, which has been termed ocean acidification (OA). The impacts of pCO2-driven acidification on immunity have been revealed recently in various marine organisms. However, the mechanism causing the reduction in phagocytosis still remains unclear.
Biomaterials connect organisms to their environments. Their function depends on biological, chemical and environmental factors, both at the time of creation and throughout the life of the material. Shifts in the chemistry of the oceans driven by anthropogenic CO2 (termed ocean acidification) have profound implications for the function of critical materials formed under these altered conditions.
Based on a survey conducted from June to July 2013, aragonite saturation state variation and control in the river-dominated marginal BoHai and Yellow seas were investigated. Surface water $Ømega$arag ranged from 2.0–3.8, whereas subsurface water $Ømega$arag was generally lower than 2.0. Temperature changes had a strong influence on $Ømega$arag through induced CO2 solubility changes in seawater. Riverine freshwater input decreased $Ømega$arag in the Changjiang and Yalu river estuaries, but induced higher $Ømega$arag in the Yellow River estuary.
The North Yellow Sea (NYS) is a western North Pacific marginal sea of major ecological and economic importance, where seasonal thermocline and subsurface cold water mass are well developed from spring to autumn. Earlier researchers have shown monthly/bimonthly declines of pH ($Δ$pH) and aragonite saturation state ($Δ$$Ømega$arag) in the NYS cold water mass.
Reconstructing aragonite saturation state based on an empirical relationship for Northern California
Ocean acidification is a global phenomenon with highly regional spatial and temporal patterns. In order to address the challenges of future ocean acidification at a regional scale, it is necessary to increase the resolution of spatial and temporal monitoring of the inorganic carbon system beyond what is currently available. One approach is to develop empirical regional models that enable aragonite saturation state to be estimated from existing hydrographic measurements, for which greater spatial coverage and longer time series exist in addition to higher spatial and temporal resolution.
Fossil fuel emissions are changing global temperature and ocean water chemistry. These changes are already altering the seasonal upwelling events that bring deeper ocean water with lower temperature, dissolved oxygen, and pH to shallower areas of the California Current Large Marine Ecosystem. For example, increase absorption of CO2 by the ocean is expected to lower the pH of current upwelling events (observed to be ̃7.5) by a further 0.4 pH units. These changes in seawater chemistry are expected to affect reproduction, growth, and survival for many coastal marine invertebrates.
Increasing atmospheric CO2 can decrease seawater pH and carbonate ions, which may adversely affect the larval survival of calcareous animals. In this study, we simulated future atmospheric CO2 concentrations (800, 1500, 2000 and 3000 ppm) and examined the effects of ocean acidification on the early development of 3 mollusks (the abalones Haliotis diversicolor and H. discus hannai and the oyster Crassostrea angulata).
Oceans worldwide are undergoing acidification due to the penetration of anthropogenic CO2 from the atmosphere1,2,3,4. The rate of acidification generally diminishes with increasing depth. Yet, slowing down of the thermohaline circulation due to global warming could reduce the pH in the deep oceans, as more organic material would decompose with a longer residence time. To elucidate this process, a time-series study at a climatically sensitive region with sufficient duration and resolution is needed.
Long-term seawater pH records are essential for evaluating the rates of ocean acidification (OA) driven by anthropogenic emissions. Widespread, natural decadal variability in seawater pH superimposes on the long-term anthropogenic variations, likely influencing the OA rates estimated from the pH records. Here, we report a record of annual seawater pH estimated using the $δ$11B proxy over the past 159 years reconstructed from a Porites coral collected to the east of Hainan Island in the northern South China Sea (SCS).
The influence of ocean acidification in deep-sea ecosystems is poorly understood, but is expected to be large owing to the presumed low tolerance of deep-sea taxa to environmental change. We used a newly developed deep-sea Free Ocean CO2 Enrichment (dp-FOCE) system1 to evaluate the potential consequences of future ocean acidification on the feeding behavior of a deep-sea echinoid, the sea urchin, Strongylocentrotus fragilis. The dp-FOCE system simulated future ocean acidification inside an experimental enclosure where observations of feeding behavior were performed.
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.
Increasing CO2 in seawater (i.e. ocean acidification) may have various and potentially adverse effects on phytoplankton dynamics and hence the organic carbon dynamics. We conducted a CO2 manipulation experiment in the Sea of Okhotsk in summer 2006 to investigate the response of the organic carbon dynamics.
Stable oxygen and carbon isotope measurements on biogenic calcite and aragonite have become standard tools for reconstructing past oceanographic and climatic change. In aquatic organisms, super(18)O / super(16)O ratios in the shell carbonate are a function of the ratio in the sea water and the calcification temperature. In contrast, super13C/ super(12)C ratios are controlled by the ratio of dissolved inorganic carbon in sea water and physiological processes such as respiration and symbiont photosynthesis.
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).
Puget Sound is a large estuary complex in the U.S. Pacific Northwest that is home to a diverse and economically important ecosystem threatened by anthropogenic impacts associated with climate change, urbanization, and ocean acidification. While ocean acidification has been studied in oceanic waters, little is known regarding its status in estuaries. Anthropogenically acidified coastal waters upwelling along the western North American continental margin can enter Puget Sound through the Strait of Juan de Fuca.
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.
A new, in-situ sensing system, Channelized Optical System (CHANOS), was recently developed to make high-resolution, simultaneous measurements of total dissolved inorganic carbon (DIC) and pH in seawater. Measurements made by this single, compact sensor can fully characterize the marine carbonate system. The system has a modular design to accommodate two independent, but similar measurement channels for DIC and pH. Both are based on spectrophotometric detection of hydrogen ion concentrations.
Multiple aspects of climate change are expected to co-occur such that ocean acidification will take place in conjunction with warming and a range of trophic changes. Previous studies have demonstrated that nutritional condition plays a significant role in the responses of invertebrates to ocean acidification, but similar studies have yet to be conducted with marine fishes. In this study, we examined the potential interactive effects of elevated CO2 levels and nutritional stress on the growth and development of northern rock sole (Lepidopsetta polyxystra).
As resource management and conservation efforts move toward multi-sector, ecosystem-based approaches, we need methods for comparing the varying responses of ecosystems to the impacts of human activities in order to prioritize management efforts, allocate limited resources, and understand cumulative effects. Given the number and variety of human activities affecting ecosystems, relatively few empirical studies are adequately comprehensive to inform these decisions. Consequently, management often turns to expert judgment for information.
The California Undercurrent transports Pacific Equatorial Water (PEW) into the Southern California Bight from the eastern tropical Pacific Ocean. PEW is characterized by higher temperatures and salinities, with lower pH, representing a source of potentially corrosive (aragonite, inline image) water to the region. We use ichthyoplankton assemblages near the cores of the California Current and the California Undercurrent to determine whether PEW influenced fish diversity.