Climate change is expected to exacerbate upwelling intensity and natural acidification in Eastern Boundaries Upwelling Systems (EBUS). Conducted between January-September 2015 in a nearshore site of the northern Humboldt Current System directly exposed to year-round upwelling episodes, this study was aimed at assessing the relationship between upwelling mediated pH-changes and functional traits of the numerically dominant planktonic copepod-grazer Acartia tonsa (Copepoda).
Based upon surveys conducted in November 2012 and June 2013, the distribution and dynamics of aragonite saturation state ($Ømega$arag) were investigated in the southern Yellow Sea (SYS) of China. In summer, surface water $Ømega$arag ranged from 2.1–3.8 and enhanced biological production fueled by Changjiang River freshwater input increased $Ømega$arag to 3.8 in the southern SYS. However, subsurface water $Ømega$arag was \textless 2.0 in the central SYS.
We test for trace element proxies in the high-magnesium calcite fraction of bamboo coral internodes by comparing environmental conditions and growth rates to the specimen-mean compositions of 73 corals that were live-caught at depths ranging from 3 to 3950 m and collected from habitats ranging from tropical coral reefs to the Antarctic slope.Comparisons were done at a large geographic scale (LGS) and for a well sampled area south of Australia, across depths at a single site, in order to help separate the effects of environmental variables that co-vary at one spatial scale, but not the other
Increasing atmospheric CO2 can decrease the 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 $μ$atm) and examined the effects of ocean acidification on the embryonic and larval stage of an infaunal clam Paphia undulate. Significant decrease of hatching of P.
Ocean acidification is expected to negatively impact many calcifying marine organisms by impairing their ability to build their protective shells and skeletons, and by causing dissolution and erosion. Here we investigated the large predatory “triton shell” gastropod Charonia lampas in acidified conditions near CO2 seeps off Shikine-jima (Japan) and compared them with individuals from an adjacent bay with seawater pH at present-day levels (outside the influence of the CO2 seep).
One of the major challenges to assessing the impact of ocean acidification on marine life is detecting and interpreting long-term change in the context of natural variability. This study addresses this need through a global synthesis of monthly pH and aragonite saturation state ($Ømega$arag) climatologies for 12 open ocean, coastal, and coral reef locations using 3-hourly moored observations of surface seawater partial pressure of CO2 and pH collected together since as early as 2010.
Mg/Ca ratios of planktonic foraminiferal tests are important tools for reconstructing past ocean temperatures at different levels of the upper water column. Yet numerous studies suggest a significant influence of calcite dissolution on Mg/Ca ratios lowering their initial signal recorded within a planktonic foraminiferal habitat. To determine the effect of dissolution, this study presents Mg/Ca ratios of eight planktonic foraminiferal species from the South China Sea sediment surface.
Ocean acidification (OA) is expected to drive the transition of coral reef ecosystems from net calcium carbonate (CaCO3) precipitating to net dissolving within the next century. Although permeable sediments represent the largest reservoir of CaCO3 in coral reefs, the dissolution of shallow CaCO3 sands under future pCO2 levels has not been measured under natural conditions. In situ, advective chamber incubations under elevated pCO2 (̃800 µatm) shifted the sediments from net precipitating to net dissolving.
Skeletal growth records in annually banded massive coral skeletons are an under-exploited archive of coral responses to environmental changes. Average linear extension and calcification rates in Indo-Pacific Porites are linearly related to average water temperatures through 23 to 30¯C. Assessing long-term trends in Porites extension and density requires caution as there is evidence of an age effect whereby in earlier growth years corals will tend to extend less and form a higher density skeleton than in later years. This does not appear to affect calcification rates.
Habitat warming and acidification experienced by intertidal invertebrates are potentially detrimental to sensitive early post-larvae of benthic marine invertebrates. To determine the potential impact of acidification and warming on a conspicuous component of the temperate intertidal fauna of the southern hemisphere, the response of newly metamorphosed juvenile (ca. 450 $μ$m diameter) sea stars (Parvulastra exigua) to increased acidification and temperature was investigated with respect to conditions recorded in the habitat (− 0.4–0.6 pH units, + 2-4 °C), in all combinations of stressors.
Echinoid sea urchins with distributions along the continental shelf and slope of the eastern Pacific often dominate the megafauna community. This occurs despite their exposure to naturally low dissolved oxygen (DO) waters (\textless60 $μ$mol kg−1) associated with the Oxygen Limited Zone and low-pH waters undersaturated with respect to calcium carbonate ($Ømega$CaCO3 \textless 1).
In order to help predict the effects of anthropogenic stressors on shallow water carbonate environments, it is important to focus research on regions containing natural oceanographic gradients, particularly with respect to interactions between oceanography and ecologically sensitive carbonate producers. The Galápagos Archipelago, an island chain in the eastern equatorial Pacific, spans a natural nutrient, pH, and temperature gradient due to the interaction of several major ocean currents.
As typical of intertidal invertebrates the asterinid seastar Parvulastra exigua experiences marked variation in environmental temperature and pH/pCO2 due to tidal exchange and diurnal patterns of photosynthesis and respiration. We characterized the temperature and pH/pCO2 conditions in the mid-intertidal, rocky-shore habitat of this species and used these data along with projections for the ocean over coming decades to define treatments in oxygen consumption experiments. The metabolic response of P.
Summary Synergies among stressors drive unanticipated changes to alternative states, yet little has been done to assess whether alleviating one or more contributing stressors may disrupt these interactions. It would be particularly useful to understand whether the synergistic effects of global and local stressors could be alleviated, leading to slower change or faster recovery, if conditions under the control of local management alone were managed (i.e. nutrient pollution). We utilized field-based mesocosms to manipulate CO2 (i.e.
An expedition to the Kavachi submarine volcano (Solomon Islands) in January 2015 was serendipitously timed with a rare lull in volcanic activity that permitted access to the inside of Kavachi's active crater and its flanks. The isolated location of Kavachi and its explosive behavior normally restrict scientific access to the volcano's summit, limiting previous observational efforts to surface imagery and peripheral water-column data.
The 3-day diurnal dynamics of carbonate system and related parameters on Luhuitou fringing reef of Sanya Bay-adjacent to the South China Sea (SCS) were observed in December of 2009 (early winter), April (spring), July (summer) and November (late-autumn) of 2010. The Luhuitou fringing reef ecosystem was generally dominated by macro and planktonic algae throughout the year except by coralline algae in winter. The system parameters showed distinct diurnal trends in the four seasons.
Large and productive fisheries occur in regions experiencing or projected to experience ocean acidification. Anchoveta (Engraulis ringens) constitute the world's largest single-species fishery and live in one of the ocean's highest pCO2 regions. We investigated the relationship of the distribution and abundance of Anchoveta eggs and larvae to natural gradients in pCO2 in the Peruvian upwelling system. Eggs and larvae, zooplankton, and data on temperature, salinity, chlorophyll a and pCO2 were collected during a cruise off Peru in 2013.
Variation in rates of herbivory may be driven by direct effects of the abiotic environment on grazers, as well as indirect effects mediated by their food. Disentangling these direct and indirect effects is of fundamental importance for ecological forecasts of changing climate on species interactions and their influence on biogenic habitat. Whilst elevated atmospheric CO2 may have direct effects on grazers with calcareous structures via ‘ocean acidification', it may also have indirect effects via changes caused to their food.
The cheilostome bryozoan Melicerita chathamensis from the continental shelf around southern New Zealand is unusual in having macroscopic annual growth checks. It thus presents an opportunity to examine annual variations in age, growth, calcification and carbonate mineralogy in a temperate bryozoan. Forty-one colonies dredged south of Snares Islands, New Zealand (47° 49.537′S, 166° 45.910′E, 166 m water depth, 2 February 2008) ranged from 2 to 9 years old and were up to 40 mm long.
Elevated pCO2 threatens coral reefs through impaired calcification. However, the extent to which elevated pCO2 affects the distribution of the pelagic larvae of scleractinian corals, and how this may be interpreted in the context of ocean acidification (OA), remains unknown. We tested the hypothesis that elevated pCO2 affects one aspect of the behavior (i.e., motility) of brooded larvae from Pocillopora damicornis in Okinawa (Japan), and used UV-transparent tubes that were 68-cm long (45 mm ID) to incubate larvae on a shallow fringing reef.