Distributions of volatile halocarbons and impacts of ocean acidification on their production in coastal waters of China

2021 ◽  
Vol 752 ◽  
pp. 141756
Author(s):  
Yu Han ◽  
Zhen He ◽  
Gui-Peng Yang
Keyword(s):  
Ocean Acidification ◽  
Coastal Waters ◽  
Volatile Halocarbons

scholarly journals Ocean acidification and high irradiance stimulate the photo-physiological fitness, growth and carbon production of the Antarctic cryptophyte <i>Geminigera cryophila</i>

2019 ◽  
Vol 16 (15) ◽  
pp. 2997-3008 ◽  
Author(s):  
Scarlett Trimborn ◽  
Silke Thoms ◽  
Pascal Karitter ◽  
Kai Bischof
Keyword(s):  
Ocean Acidification ◽  
Coastal Waters ◽  
High Irradiance ◽  
High Pco2 ◽  
Experimental Conditions ◽  
Phytoplankton Assemblages ◽  
Beneficial Effects ◽  
Carbon Production ◽  
Geminigera Cryophila ◽  
The Antarctic

Abstract. Ecophysiological studies on Antarctic cryptophytes to assess whether climatic changes such as ocean acidification and enhanced stratification affect their growth in Antarctic coastal waters in the future are lacking so far. This is the first study that investigates the combined effects of the increasing availability of pCO2 (400 and 1000 µatm) and irradiance (20, 200 and 500 µmol photons m−2 s−1) on growth, elemental composition and photophysiology of the Antarctic cryptophyte Geminigera cryophila. Under ambient pCO2, this species was characterized by a pronounced sensitivity to increasing irradiance with complete growth inhibition at the highest light intensity. Interestingly, when grown under high pCO2 this negative light effect vanished, and it reached the highest rates of growth and particulate organic carbon production at the highest irradiance compared to the other tested experimental conditions. Our results for G. cryophila reveal beneficial effects of ocean acidification in conjunction with enhanced irradiance on growth and photosynthesis. Hence, cryptophytes such as G. cryophila may be potential winners of climate change, potentially thriving better in more stratified and acidic coastal waters and contributing in higher abundance to future phytoplankton assemblages of coastal Antarctic waters.

Upwelling Bays: How Coastal Upwelling Controls Circulation, Habitat, and Productivity in Bays

2020 ◽  
Vol 12 (1) ◽  
pp. 415-447 ◽  
Author(s):  
John L. Largier
Keyword(s):  
Ocean Acidification ◽  
Wind Stress ◽  
Coastal Waters ◽  
Coastal Upwelling ◽  
Coastal Currents ◽  
Local Wind ◽  
Phytoplankton Blooms ◽  
Local Extrema ◽  
High Recruitment

Bays in coastal upwelling regions are physically driven and biochemically fueled by their interaction with open coastal waters. Wind-driven flow over the shelf imposes a circulation in the bay, which is also influenced by local wind stress and thermal bay–ocean density differences. Three types of bays are recognized based on the degree of exposure to coastal currents and winds (wide-open bays, square bays, and elongated bays), and the characteristic circulation and stratification patterns of each type are described. Retention of upwelled waters in bays allows for dense phytoplankton blooms that support productive bay ecosystems. Retention is also important for the accumulation of larvae, which accounts for high recruitment in bays. In addition, bays are coupled to the shelf ecosystem through export of plankton-rich waters during relaxation events. Ocean acidification and deoxygenation are a concern in bays because local extrema can develop beneath strong stratification.

Ocean acidification impacts primary and bacterial production in Antarctic coastal waters during austral summer

2018 ◽  
Vol 498 ◽  
pp. 46-60 ◽  
Author(s):  
K.J. Westwood ◽  
P.G. Thomson ◽  
R.L. van den Enden ◽  
L.E. Maher ◽  
S.W. Wright ◽  
...  
Keyword(s):  
Ocean Acidification ◽  
Coastal Waters ◽  
Bacterial Production ◽  
Austral Summer

scholarly journals Ocean acidification disrupts the orientation of postlarval Caribbean spiny lobsters

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Philip M. Gravinese ◽  
Heather N. Page ◽  
Casey B. Butler ◽  
Angelo Jason Spadaro ◽  
Clay Hewett ◽  
...  
Keyword(s):  
Ocean Acidification ◽  
Time Scales ◽  
Coastal Waters ◽  
Chemical Cues ◽  
Spiny Lobster ◽  
Episodic Acidification ◽  
Anthropogenic Inputs ◽  
Seawater Ph ◽  
Y Maze ◽  
The Caribbean

Abstract Anthropogenic inputs into coastal ecosystems are causing more frequent environmental fluctuations and reducing seawater pH. One such ecosystem is Florida Bay, an important nursery for the Caribbean spiny lobster, Panulirus argus. Although adult crustaceans are often resilient to reduced seawater pH, earlier ontogenetic stages can be physiologically limited in their tolerance to ocean acidification on shorter time scales. We used a Y-maze chamber to test whether reduced-pH seawater altered the orientation of spiny lobster pueruli toward chemical cues produced by Laurencia spp. macroalgae, a known settlement cue for the species. We tested the hypothesis that pueruli conditioned in reduced-pH seawater would be less responsive to Laurencia spp. chemical cues than pueruli in ambient-pH seawater by comparing the proportion of individuals that moved to the cue side of the chamber with the proportion that moved to the side with no cue. We also recorded the amount of time (sec) before a response was observed. Pueruli conditioned in reduced-pH seawater were less responsive and failed to select the Laurencia cue. Our results suggest that episodic acidification of coastal waters might limit the ability of pueruli to locate settlement habitats, increasing postsettlement mortality.

scholarly journals Biogeochemical feedbacks to ocean acidification in a cohesive photosynthetic sediment

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Kay Vopel ◽  
Alexis Marshall ◽  
Shelly Brandt ◽  
Adam Hartland ◽  
Charles K. Lee ◽  
...  
Keyword(s):  
Ocean Acidification ◽  
Coastal Waters ◽  
Metabolic Response ◽  
Sediment Cores ◽  
Biogeochemical Processes ◽  
Ambient Seawater ◽  
Calcite Dissolution ◽  
Sand Control ◽  
Negative Effect ◽  
And Control

AbstractEcosystem feedbacks in response to ocean acidification can amplify or diminish diel pH oscillations in productive coastal waters. Benthic microalgae generate such oscillations in sediment porewater and here we ask how CO2 enrichment (acidification) of the overlying seawater alters these in the absence and presence of biogenic calcite. We placed a 1-mm layer of ground oyster shells, mimicking the arrival of dead calcifying biota (+Calcite), or sand (Control) onto intact silt sediment cores, and then gradually increased the pCO2 in the seawater above half of +Calcite and Control cores from 472 to 1216 μatm (pH 8.0 to 7.6, CO2:HCO3− from 4.8 to 9.6 × 10−4). Porewater [O2] and [H+] microprofiles measured 16 d later showed that this enrichment had decreased the O2 penetration depth (O2-pd) in +Calcite and Control, indicating a metabolic response. In CO2-enriched seawater: (1) sediment biogeochemical processes respectively added and removed more H+ to and from the sediment porewater in darkness and light, than in ambient seawater increasing the amplitude of the diel porewater [H+] oscillations, and (2) in darkness, calcite dissolution in +Calcite sediment decreased the porewater [H+] below that in overlying seawater, reversing the sediment–seawater H+ flux and decreasing the amplitude of diel [H+] oscillations. This dissolution did not, however, counter the negative effect of CO2 enrichment on O2-pd. We now hypothesise that feedback to CO2 enrichment—an increase in the microbial reoxidation of reduced solutes with O2—decreased the sediment O2-pd and contributed to the enhanced porewater acidification.

scholarly journals Biogeochemical Feedbacks to Ocean Acidification in a Cohesive Photosynthetic Sediment

2021 ◽  
Author(s):  
Kay Vopel ◽  
Alexis Marshall ◽  
Shelly Brandt ◽  
Adam Hartland ◽  
Charles K Lee ◽  
...  
Keyword(s):  
Ocean Acidification ◽  
Coastal Waters ◽  
Metabolic Response ◽  
Sediment Cores ◽  
Ambient Seawater ◽  
Dark Light ◽  
Sand Control ◽  
Negative Effect ◽  
And Control ◽  
Do So

Abstract Ecosystem feedbacks in response to ocean acidification can amplify or diminish the diel pH oscillations that characterize productive coastal waters. We report that benthic microalgae generate such oscillations in the porewater of cohesive sediment and ask how carbonation (acidification) of the overlying seawater alters these in the absence and presence of biogenic calcite. To do so, we placed a 1-mm layer of ground oyster shells (Treatment) or sand (Control) onto intact sediment cores free of large dwelling fauna, and then gradually increased the pCO2 in the seawater above half of the Treatment and Control cores from 472 to 1216 μatm (pH 8.0 to 7.6, CO2:HCO3- from 4.8 to 9.6 x 10-4). Vertical porewater [O2] and [H+] microprofiles measured 16 d later showed that this carbonation had decreased O2 penetration in all cores, indicating a metabolic response. In carbonated seawater: (1) sediment biogeochemical processes added and removed more H+ to and from the porewater in darkness and light, respectively, than in ambient seawater increasing the amplitude of the dark–light porewater [H+] oscillations, and (2) the dissolution of calcite decreased the porewater [H+] below that in overlying seawater, reversing the dark sediment–seawater H+ flux and decreasing the amplitude of diel [H+] oscillations. This dissolution did not, however, counter the negative effect of carbonation on sediment O2 penetration. We hypothesise that the latter effect and the observed enhanced acidification of the sediment porewater were caused by an ecosystem feedback: a CO2-induced increase in the microbial reoxidation of reduced solutes with O2.

scholarly journals The role of soils in the regulation of ocean acidification

2021 ◽  
Vol 376 (1834) ◽  
pp. 20200174
Author(s):  
P. Renforth ◽  
J. S. Campbell
Keyword(s):  
Ocean Acidification ◽  
Coastal Waters ◽  
Chemical Weathering ◽  
Buffering Capacity ◽  
Theme Issue ◽  
Secondary Minerals ◽  
Carbon Transfer ◽  
Drainage Waters ◽  
Partial Reversal

Soils play an important role in mediating chemical weathering reactions and carbon transfer from the land to the ocean. Proposals to increase the contribution of alkalinity to the oceans through ‘enhanced weathering’ as a means to help prevent climate change are gaining increasing attention. This would augment the existing connection between the biogeochemical function of soils and alkalinity levels in the ocean. The feasibility of enhanced weathering depends on the combined influence of what minerals are added to soils, the formation of secondary minerals in soils and the drainage regime, and the partial pressure of respired CO 2 around the dissolving mineral. Increasing the alkalinity levels in the ocean through enhanced weathering could help to ameliorate the effects of ocean acidification in two ways. First, enhanced weathering would slightly elevate the pH of drainage waters, and the receiving coastal waters. The elevated pH would result in an increase in carbonate mineral saturation states, and a partial reversal in the effects of elevated CO 2 . Second, the increase in alkalinity would help to replenish the ocean's buffering capacity by maintaining the ‘Revelle Factor’, making the oceans more resilient to further CO 2 emissions. However, there is limited research on the downstream and oceanic impacts of enhanced weathering on which to base deployment decisions. This article is part of the theme issue ‘The role of soils in delivering Nature's Contributions to People’.

Ocean acidification impacts on biomass and fatty acid composition of a post-bloom marine plankton community

2020 ◽  
Vol 647 ◽  
pp. 49-64 ◽  
Author(s):  
I Dörner ◽  
H Hauss ◽  
N Aberle ◽  
K Lohbeck ◽  
C Spisla ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Fatty Acid Composition ◽  
Fatty Acid ◽  
Ocean Acidification ◽  
Coastal Waters ◽  
Saturated Fatty Acids ◽  
Fatty Acid Content ◽  
Plankton Community ◽  
Trophic Levels ◽  
Control Group

A mesocosm approach was used to investigate the effects of ocean acidification (OA) on a natural plankton community in coastal waters off Norway by manipulating CO2 partial pressure (pCO2). Eight enclosures were deployed in the Raunefjord near Bergen. Treatment levels were ambient (~320 µatm) and elevated pCO2 (~2000 µatm), each in 4 replicate enclosures. The experiment lasted for 53 d in May-June 2015. To assess impacts of OA on the plankton community, phytoplankton and protozooplankton biomass and total seston fatty acid content were analyzed. In both treatments, the plankton community was dominated by the dinoflagellate Ceratium longipes. In the elevated pCO2 treatment, however, biomass of this species as well as that of other dinoflagellates was strongly negatively affected. At the end of the experiment, total dinoflagellate biomass was 4-fold higher in the control group than under elevated pCO2 conditions. In a size comparison of C. longipes, cell size in the high pCO2 treatment was significantly larger. The ratio of polyunsaturated fatty acids to saturated fatty acids of seston decreased at high pCO2. In particular, the concentration of docosahexaenoic acid (C 22:6n3c), essential for development and reproduction of metazoans, was less than half at high pCO2 compared to ambient pCO2. Thus, elevated pCO2 led to a deterioration in the quality and quantity of food in a natural plankton community, with potential consequences for the transfer of matter and energy to higher trophic levels

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