scholarly journals Sensitivity towards elevated <i>p</i>CO<sub>2</sub> in great scallop (<i>Pecten maximus</i> Lamarck) embryos and fed larvae

2016 ◽  
Author(s):  
Sissel Andersen ◽  
Ellen S. Grefsrud ◽  
Torstein Harboe
Keyword(s):  
Ocean Acidification ◽  
Shell Growth ◽  
Elevated Pco2 ◽  
Pecten Maximus ◽  
Negative Effects ◽  
Great Scallop ◽  
Scallop Larvae ◽  
Negative Effect ◽  
Seawater Carbonate Chemistry

Abstract. The increasing amount of dissolved anthropogenic CO2 has caused a drop in pH-values in the open ocean known as ocean acidification. This change in seawater carbonate chemistry has been shown to have a negative effect on a number of marine organisms. Early life stages are the most vulnerable, and especially the organisms that produce calcified structures in the phylum Mollusca. Few studies have looked at effects on scallops, and this is the first study presented including fed larvae of the great scallop (Pecten maximus) followed until day 14 post-fertilization. Fertilized eggs from unexposed parents were exposed to three levels of pCO2 using four replicate units: 465 (ambient), 768 and 1294 μatm, corresponding to pHNBS of 7.94, 7.74 and 7.54, respectively. All of the observed parameters were negatively affected by elevated pCO2: survival, larval development, shell growth and normal shell development. The latter was observed to be affected only two days after fertilization. Negative effects on the fed larvae at day 7 were similar to what was shown earlier for unfed P. maximus larvae. Growth rate in the group at 768 μatm seemed to decline after day 7, indicating that the ability to overcome the environmental change at moderately elevated pCO2 was lost over time. Food availability may not decrease the sensitivity to elevated pCO2 in scallop larvae. Unless genetic adaptation and acclimatization counteract the negative effects of long term elevated pCO2, populations of scallops may be negatively affected by ocean acidification in the future.

scholarly journals Sensitivity towards elevated <i>p</i>CO<sub>2</sub> in great scallop (<i>Pecten maximus</i> Lamarck) embryos and fed larvae

2017 ◽  
Vol 14 (3) ◽  
pp. 529-539 ◽  
Author(s):  
Sissel Andersen ◽  
Ellen S. Grefsrud ◽  
Torstein Harboe
Keyword(s):  
Shell Growth ◽  
Elevated Pco2 ◽  
Pecten Maximus ◽  
Early Life Stages ◽  
Negative Effects ◽  
Ph Values ◽  
Great Scallop ◽  
Negative Effect ◽  
Seawater Carbonate Chemistry

Abstract. The increasing amount of dissolved anthropogenic CO2 has caused a drop in pH values in the open ocean known as ocean acidification. This change in seawater carbonate chemistry has been shown to have a negative effect on a number of marine organisms. Early life stages are the most vulnerable, and especially the organisms that produce calcified structures in the phylum Mollusca. Few studies have looked at effects on scallops, and this is the first study presented including fed larvae of the great scallop (Pecten maximus) followed until day 14 post-fertilization. Fertilized eggs from unexposed parents were exposed to three levels of pCO2 using four replicate units: 465 (ambient), 768 and 1294 µatm, corresponding to pHNIST of 7.94, 7.75 (−0.19 units) and 7.54 (−0.40 units), respectively. All of the observed parameters were negatively affected by elevated pCO2: survival, larval development, shell growth and normal shell development. The latter was observed to be affected only 2 days after fertilization. Negative effects on the fed larvae at day 7 were similar to what was shown earlier for unfed P. maximus larvae. Growth rate in the group at 768 µatm seemed to decline after day 7, indicating that the ability to overcome the environmental change at moderately elevated pCO2 was lost over time. The present study shows that food availability does not decrease the sensitivity to elevated pCO2 in P. maximus larvae. Unless genetic adaptation and acclimatization counteract the negative effects of long term elevated pCO2, recruitment in populations of P. maximus will most likely be negatively affected by the projected drop of 0.06–0.32 units in pH within year 2100.

scholarly journals Effect of increased <i>p</i>CO<sub>2</sub> level on early shell development in great scallop (<i>Pecten maximus</i> Lamarck) larvae

2013 ◽  
Vol 10 (10) ◽  
pp. 6161-6184 ◽  
Author(s):  
S. Andersen ◽  
E. S. Grefsrud ◽  
T. Harboe
Keyword(s):  
Marine Invertebrates ◽  
Shell Growth ◽  
Elevated Pco2 ◽  
Pecten Maximus ◽  
Long Term Effects ◽  
Negative Effects ◽  
Pco2 Level ◽  
Larval Stages ◽  
Great Scallop ◽  
Veliger Larvae

Abstract. As a result of high anthropogenic CO2 emissions, the concentration of CO2 in the oceans has increased, causing a decrease in pH, known as ocean acidification (OA). Numerous studies have shown negative effects on marine invertebrates, and also that the early life stages are the most sensitive to OA. We studied the effects of OA on embryos and unfed larvae of the great scallop (Pecten maximus Lamarck), at pCO2 levels of 469 (ambient), 807, 1164, and 1599 μatm until seven days after fertilization. To our knowledge, this is the first study on OA effects on larvae of this species. A drop in pCO2 level the first 12 h was observed in the elevated pCO2 groups due to a discontinuation in water flow to avoid escape of embryos. When the flow was restarted, pCO2 level stabilized and was significantly different between all groups. OA affected both survival and shell growth negatively after seven days. Survival was reduced from 45% in the ambient group to 12% in the highest pCO2 group. Shell length and height were reduced by 8 and 15%, respectively, when pCO2 increased from ambient to 1599 μatm. Development of normal hinges was negatively affected by elevated pCO2 levels in both trochophore larvae after two days and veliger larvae after seven days. After seven days, deformities in the shell hinge were more connected to elevated pCO2 levels than deformities in the shell edge. Embryos stained with calcein showed fluorescence in the newly formed shell area, indicating calcification of the shell at the early trochophore stage between one and two days after fertilization. Our results show that P. maximus embryos and early larvae may be negatively affected by elevated pCO2 levels within the range of what is projected towards year 2250, although the initial drop in pCO2 level may have overestimated the effect of the highest pCO2 levels. Future work should focus on long-term effects on this species from hatching, throughout the larval stages, and further into the juvenile and adult stages.

scholarly journals Effect of increased <i>p</i>CO<sub>2</sub> on early shell development in great scallop (<i>Pecten maximus</i> Lamarck) larvae

2013 ◽  
Vol 10 (2) ◽  
pp. 3281-3310 ◽  
Author(s):  
S. Andersen ◽  
E. S. Grefsrud ◽  
T. Harboe
Keyword(s):  
Marine Invertebrates ◽  
Shell Growth ◽  
Elevated Pco2 ◽  
Pecten Maximus ◽  
Negative Effects ◽  
Co2 Partial Pressure ◽  
Great Scallop ◽  
Egg Number ◽  
Veliger Larvae ◽  
Trochophore Stage

Abstract. As a result of high anthropogenic emission of CO2, partial pressure of carbon dioxide (pCO2) in the oceans has increased causing a drop in pH, known as ocean acidification (OA). Numerous studies have shown negative effects on marine invertebrates, and that the early life stages are the most sensitive to OA. We studied the effects on embryo and larvae of great scallop (Pecten maximus L.), using mean pCO2-levels of 477 (ambient), 821, 1184, and 1627 ppm. OA affected both survival and shell growth negatively after seven days. Growth was reduced with 5–10% when pCO2 increased from ambient 477 ppm to 1627 ppm, and survival based on egg number was reduced from 40.4% in the ambient group to 10.7% in the highest pCO2-group. Larvae/embryos stained with calcein one day after fertilization, showed fluorescence in the newly formed shell area indicating calcification of the shell already at the trochophore stage. Shell hinge deformities were observed at elevated pCO2-levels in trochophore larvae after two days. After seven days, deformities in both shell hinge and shell edge were observed in veliger larvae at elevated pCO2-levels. Although the growth showed a moderate reduction, survival rate and increased amount of deformed larvae indicates that P. Maximus larvae are affected by elevated pCO2 levels within the range of what is projected for the next century.

scholarly journals Long-term subjective memory after electroconvulsive therapy

BJPsych Open ◽  
2020 ◽  
Vol 6 (2) ◽  
Author(s):  
Robert Sigström ◽  
Axel Nordenskjöld ◽  
Anders Juréus ◽  
Caitlin Clements ◽  
Erik Joas ◽  
...  
Keyword(s):  
Electroconvulsive Therapy ◽  
Memory Impairment ◽  
Rating Scale ◽  
Final Analysis ◽  
Negative Effects ◽  
Subjective Memory ◽  
Subjective Memory Impairment ◽  
Negative Effect ◽  
Negative Expectations

Background There have been reports of long-term subjective memory worsening after electroconvulsive therapy (ECT). Aims To study the prevalence and risk factors of long-term subjective memory worsening among patients receiving ECT in routine clinical practice. Method Patients (n = 535, of whom 277 were included in the final analysis) were recruited from eight Swedish hospitals. Participants' subjective memory impairment was assessed before ECT and a median of 73 days after ECT using the memory item from the Comprehensive Psychopathological Rating Scale. Participants also rated their pre-ECT expectations and post-ECT evaluations of the effect of ECT on memory on a 7-point scale. We used ordinal regression to identify variables associated with subjective memory worsening and negative evaluations of the effect of ECT on memory. Results Comparisons of pre- and post-ECT assessments showed that subjective memory worsened in 16.2% of participants, remained unchanged in 52.3% and improved in 31.4%. By contrast, when asked to evaluate the effect of ECT on memory after treatment 54.6% reported a negative effect. Subjective memory worsening was associated with negative expectations before ECT, younger age and shorter duration of follow-up. Conclusions Although subjective memory improved more often than it worsened when assessed before and after ECT, a majority of patients reported that ECT had negative effects on their memory when retrospectively asked how ECT had affected it. This might suggest that some patients attribute pre-existing subjective memory impairment to ECT. Clinicians should be aware that negative expectations are associated with subjective worsening of memory after ECT.

scholarly journals High frequency Barium profiles in shells of the Great Scallop <i>Pecten maximus</i>: a methodical long-term and multi-site survey in Western Europe

2008 ◽  
Vol 5 (5) ◽  
pp. 3665-3698 ◽  
Author(s):  
A. Barats ◽  
D. Amouroux ◽  
L. Chauvaud ◽  
C. Pécheyran ◽  
A. Lorrain ◽  
...  
Keyword(s):  
High Frequency ◽  
Western Europe ◽  
Pecten Maximus ◽  
Coastal Environments ◽  
Great Scallop ◽  
Site Survey ◽  
Scallop Shells ◽  
Bay Of Brest ◽  
Long Term Survey

Abstract. Skeletal barium/calcium ([Ba]/[Ca])shell ratios were measured every third daily striae in 39 flat valves of the Great Scallop Pecten maximus (2-year old; 3 shells/year) collected in temperate coastal environments of Western Europe. Variations of ([Ba]/[Ca])shell ratio were first demonstrated reproducible for several scallop individuals from the same population, over a 7-year period (1998–2004), and from different coastal environments in France (42–49° N). As in previous studies, ([Ba]/[Ca])shell profiles exhibited a background ratio punctuated by transient maxima occurring in summer. Background partition coefficient (DBa=0.11±0.03, in 2000) was similar to that previously reported in P. maximus shells (DBa=0.18), suggesting a direct shell uptake of dissolved seawater Ba (Gillikin et al., 2008). Special attention was then dedicated to the complete monitoring of high resolution ([Ba]/[Ca])shell profiles in bivalve shells (7 years, Bay of Brest) to better constrain environmental processes influencing both the occurrence and the amplitude of summer peaks. In 2000, seawater Ba analyses underlined significant particulate Ba inputs at the seawater interface (SWI) during ([Ba]/[Ca])shell peak events. These Ba inputs are suggested to be subsequent to and rather induced by a pelagic biogenic process. The long term survey revealed first that archived Ba within the shell cannot be used as a direct paleo productivity tracer, and second that complex pelagic/benthic processes in the Ba cycle are responsible of particulate Ba inputs to the SWI, subsequently taken up by the bivalve and recorded as higher ([Ba]/[Ca])shell ratios. When these processes will be better constrained, high frequency observations of Ba in scallop shells would provide new insights into filter feeding dynamics and into Ba biogeochemistry in coastal environments.

scholarly journals Shell mineralogy of a foundational marine species, Mytilus californianus, over half a century in a changing ocean

2021 ◽  
Vol 118 (3) ◽  
pp. e2004769118
Author(s):  
Elizabeth M. Bullard ◽  
Ivan Torres ◽  
Tianqi Ren ◽  
Olivia A. Graeve ◽  
Kaustuv Roy
Keyword(s):  
Ocean Acidification ◽  
Historical Data ◽  
Mineralogical Composition ◽  
Marine Species ◽  
Mytilus Californianus ◽  
Negative Effects ◽  
Saturation State ◽  
Long Term Changes ◽  
Time Periods

Anthropogenic warming and ocean acidification are predicted to negatively affect marine calcifiers. While negative effects of these stressors on physiology and shell calcification have been documented in many species, their effects on shell mineralogical composition remains poorly known, especially over longer time periods. Here, we quantify changes in the shell mineralogy of a foundation species, Mytilus californianus, under 60 y of ocean warming and acidification. Using historical data as a baseline and a resampling of present-day populations, we document a substantial increase in shell calcite and decrease in aragonite. These results indicate that ocean pH and saturation state, not temperature or salinity, play a strong role in mediating the shell mineralogy of this species and reveal long-term changes in this trait under ocean acidification.

scholarly journals Reviews and Syntheses: Responses of coccolithophores to ocean acidification: a meta-analysis

2015 ◽  
Vol 12 (6) ◽  
pp. 1671-1682 ◽  
Author(s):  
J. Meyer ◽  
U. Riebesell
Keyword(s):  
Ocean Acidification ◽  
Dissolved Inorganic Carbon ◽  
Meta Analysis ◽  
Physiological Responses ◽  
Total Alkalinity ◽  
Adaptive Responses ◽  
Negative Effects ◽  
Ecological Fitness ◽  
Negative Effect ◽  
Gephyrocapsa Oceanica

Abstract. Concerning their sensitivity to ocean acidification, coccolithophores, a group of calcifying single-celled phytoplankton, are one of the best-studied groups of marine organisms. However, in spite of the large number of studies investigating coccolithophore physiological responses to ocean acidification, uncertainties still remain due to variable and partly contradictory results. In the present study we have used all existing data in a meta-analysis to estimate the effect size of future pCO2 changes on the rates of calcification and photosynthesis and the ratio of particulate inorganic to organic carbon (PIC / POC) in different coccolithophore species. Our results indicate that ocean acidification has a negative effect on calcification and the cellular PIC / POC ratio in the two most abundant coccolithophore species: Emiliania huxleyi and Gephyrocapsa oceanica. In contrast, the more heavily calcified species Coccolithus braarudii did not show a distinct response when exposed to elevated pCO2/reduced pH. Photosynthesis in Gephyrocapsa oceanica was positively affected by high CO2, while no effect was observed for the other coccolithophore species. There was no indication that the method of carbonate chemistry manipulation was responsible for the inconsistent results regarding observed responses in calcification and the PIC / POC ratio. The perturbation method, however, appears to affect photosynthesis, as responses varied significantly between total alkalinity (TA) and dissolved inorganic carbon (DIC) manipulations. These results emphasize that coccolithophore species respond differently to ocean acidification, both in terms of calcification and photosynthesis. Where negative effects occur, they become evident at CO2 levels in the range projected for this century in the case of unabated CO2 emissions. As the data sets used in this meta-analysis do not account for adaptive responses, ecological fitness and ecosystem interactions, the question remains as to how these physiological responses play out in the natural environment.

scholarly journals An integrated investigation of the effects of ocean acidification on adult abalone (Haliotis tuberculata)

2020 ◽  
Vol 77 (2) ◽  
pp. 757-772
Author(s):  
Solène Avignon ◽  
Stéphanie Auzoux-Bordenave ◽  
Sophie Martin ◽  
Philippe Dubois ◽  
Aïcha Badou ◽  
...  
Keyword(s):  
Ocean Acidification ◽  
Shell Growth ◽  
Microscopy Imaging ◽  
Vital Functions ◽  
Internal Fluid ◽  
Haliotis Tuberculata ◽  
Structural Responses ◽  
Seawater Carbonate Chemistry ◽  
Ph Decrease ◽  
Parameter Approach

Abstract Ocean acidification (OA) and its subsequent changes in seawater carbonate chemistry are threatening the survival of calcifying organisms. Due to their use of calcium carbonate to build their shells, marine molluscs are particularly vulnerable. This study investigated the effect of CO2-induced OA on adult European abalone (Haliotis tuberculata) using a multi-parameter approach. Biological (survival, growth), physiological (pHT of haemolymph, phagocytosis, metabolism, gene expression), and structural responses (shell strength, nano-indentation measurements, Scanning electron microscopy imaging of microstructure) were evaluated throughout a 5-month exposure to ambient (8.0) and low (7.7) pH conditions. During the first 2 months, the haemolymph pH was reduced, indicating that abalone do not compensate for the pH decrease of their internal fluid. Overall metabolism and immune status were not affected, suggesting that abalone maintain their vital functions when facing OA. However, after 4 months of exposure, adverse effects on shell growth, calcification, microstructure, and resistance were highlighted, whereas the haemolymph pH was compensated. Significant reduction in shell mechanical properties was revealed at pH 7.7, suggesting that OA altered the biomineral architecture leading to a more fragile shell. It is concluded that under lower pH, abalone metabolism is maintained at a cost to growth and shell integrity. This may impact both abalone ecology and aquaculture.

scholarly journals Rapid multi-generational acclimation of coralline algal reproductive structures to ocean acidification

2021 ◽  
Vol 288 (1950) ◽  
Author(s):  
B. Moore ◽  
S. Comeau ◽  
M. Bekaert ◽  
A. Cossais ◽  
A. Purdy ◽  
...  
Keyword(s):  
Ocean Acidification ◽  
Growth Rates ◽  
Natural Habitat ◽  
Algal Growth ◽  
Coralline Algae ◽  
Reproductive Structures ◽  
Highly Sensitive ◽  
Negative Effect ◽  
Coral Reef Ecosystems

The future of coral reef ecosystems is under threat because vital reef-accreting species such as coralline algae are highly susceptible to ocean acidification. Although ocean acidification is known to reduce coralline algal growth rates, its direct effects on the development of coralline algal reproductive structures (conceptacles) is largely unknown. Furthermore, the long-term, multi-generational response of coralline algae to ocean acidification is extremely understudied. Here, we investigate how mean pH, pH variability and the pH regime experienced in their natural habitat affect coralline algal conceptacle abundance and size across six generations of exposure. We show that second-generation coralline algae exposed to ocean acidification treatments had conceptacle abundances 60% lower than those kept in present-day conditions, suggesting that conceptacle development is initially highly sensitive to ocean acidification. However, this negative effect of ocean acidification on conceptacle abundance disappears after three generations of exposure. Moreover, we show that this transgenerational acclimation of conceptacle development is not facilitated by a trade-off with reduced investment in growth, as higher conceptacle abundances are associated with crusts with faster growth rates. These results indicate that the potential reproductive output of coralline algae may be sustained under future ocean acidification.

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