scholarly journals Effects of elevated CO2 levels on eggs and larvae of a North Pacific flatfish

2015 ◽  
Vol 73 (3) ◽  
pp. 981-990 ◽  
Author(s):  
Thomas P. Hurst ◽  
Benjamin J. Laurel ◽  
Jeremy T. Mathis ◽  
Lauren R. Tobosa

Abstract The Bering Sea and Gulf of Alaska support a number of commercially important flatfish fisheries. These high latitude ecosystems are predicted to be most immediately impacted by ongoing ocean acidification, but the range of responses by commercial fishery species has yet to be fully explored. In this study, we examined the growth responses of northern rock sole (Lepidopsetta polyxystra) eggs and larvae across a range of CO2 levels (ambient to 1500 µatm) to evaluate the potential sensitivity to ocean acidification. Laboratory-spawned eggs and larvae were reared at 8°C in a flow-through culture system in which CO2 levels were maintained via computer-controlled injection of CO2 into a seawater conditioning tank. Overall, we observed only minor effects of elevated CO2 level on sizes of northern rock sole larvae. Size at hatch differed among offspring from four different females, but there was no significant effect of CO2 level on egg survival or size at hatch. In three separate larval growth trials, there was little effect of CO2 level on growth rates through the first 28 d post-hatch (DPH). However, in the one trial extended to 60 DPH, fish reared at the highest CO2 level had lower condition factors after 28 DPH, suggesting that larvae undergoing metamorphosis may be more sensitive to environmental hypercapnia than earlier pre-flexion stages. These results suggest that while early life stages of northern rock sole are less sensitive to ocean acidification than previously examined flatfish, they may be more sensitive to elevated CO2 levels than a previously studied gadid with a similar geographic range.

2013 ◽  
Vol 70 (4) ◽  
pp. 812-822 ◽  
Author(s):  
Thomas P. Hurst ◽  
Elena R. Fernandez ◽  
Jeremy T. Mathis

Abstract Hurst, T. P., Fernandez, E. R., and Mathis, J. T. 2013. Effects of ocean acidification on hatch size and larval growth of walleye pollock (Theragra chalcogramma). – ICES Journal of Marine Science, 70: 812–822. Rising atmospheric concentrations of CO2 are predicted to decrease the pH of high-latitude oceans by 0.3–0.5 units by 2100. Because of their limited capacity for ion exchange, embryos and larvae of marine fishes are predicted to be more sensitive to elevated CO2 than juveniles and adults. Eggs and larvae of walleye pollock (Theragra chalcogramma) were incubated across a broad range of CO2 levels (280–2100 µatm) to evaluate sensitivity in this critical resource species. Slightly elevated CO2 levels (∼450 µatm) resulted in earlier hatching times, but differences among egg batches were greater than those observed across CO2 treatments. Egg batches differed significantly in size-at-hatch metrics, but we observed no consistent effect of CO2 level. In three independent experiments, walleye pollock were reared at ambient and elevated CO2 levels through the early larval stage (to ∼30 days post-hatch). Across trials, there were only minor effects of CO2 level on size and growth rate, but fish in the ambient treatments tended to be slightly smaller than fish reared at elevated CO2 levels. These results suggest that growth potential of early life stages of walleye pollock is resilient with respect to the direct physiological effects of ocean acidification.


2015 ◽  
Vol 12 (1) ◽  
pp. 1-20 ◽  
Author(s):  
J. Mu ◽  
F. Jin ◽  
J. Wang ◽  
N. Zheng ◽  
Y. Cong

Abstract. The potential effects of elevated CO2 level and reduced carbonate saturation state in marine environment on fishes and other non-calcified organisms are still poorly known. In present study, we investigated the effects of ocean acidification on embryogenesis and organogenesis of newly hatched larvae of marine medaka (Oryzias melastigma) after 21 d exposure of eggs to different artificially acidified seawater (pH 7.6 and 7.2, respectively), and compared with those in control group (pH 8.2). Results showed that CO2-driven seawater acidification (pH 7.6 and 7.2) had no detectable effect on hatching time, hatching rate, and heart rate of embryos. However, the deformity rate of larvae in pH 7.2 treatment was significantly higher than that in control treatment. The left and right sagitta areas did not differ significantly from each other in each treatment. However, the mean sagitta area of larvae in pH 7.6 treatment was significantly smaller than that in the control (p = 0.024). These results suggest that although marine medaka might be more tolerant of elevated CO2 than some other fishes, the effect of elevated CO2 level on the calcification of otolith is likely to be the most susceptibly physiological process of pH regulation in early life stage of marine medaka.


2020 ◽  
Vol 8 (1) ◽  
Author(s):  
Andrea Y Frommel ◽  
Justin Carless ◽  
Brian P V Hunt ◽  
Colin J Brauner

Abstract Pacific salmon stocks are in decline with climate change named as a contributing factor. The North Pacific coast of British Columbia is characterized by strong temporal and spatial heterogeneity in ocean conditions with upwelling events elevating CO2 levels up to 10-fold those of pre-industrial global averages. Early life stages of pink salmon have been shown to be affected by these CO2 levels, and juveniles naturally migrate through regions of high CO2 during the energetically costly phase of smoltification. To investigate the physiological response of out-migrating wild juvenile pink salmon to these naturally occurring elevated CO2 levels, we captured fish in Georgia Strait, British Columbia and transported them to a marine lab (Hakai Institute, Quadra Island) where fish were exposed to one of three CO2 levels (850, 1500 and 2000 μatm CO2) for 2 weeks. At ½, 1 and 2 weeks of exposure, we measured their weight and length to calculate condition factor (Fulton’s K), as well as haematocrit and plasma [Cl−]. At each of these times, two additional stressors were imposed (hypoxia and temperature) to provide further insight into their physiological condition. Juvenile pink salmon were largely robust to elevated CO2 concentrations up to 2000 μatm CO2, with no mortality or change in condition factor over the 2-week exposure duration. After 1 week of exposure, temperature and hypoxia tolerance were significantly reduced in high CO2, an effect that did not persist to 2 weeks of exposure. Haematocrit was increased by 20% after 2 weeks in the CO2 treatments relative to the initial measurements, while plasma [Cl−] was not significantly different. Taken together, these data indicate that juvenile pink salmon are quite resilient to naturally occurring high CO2 levels during their ocean outmigration.


2007 ◽  
Vol 34 (12) ◽  
pp. 1137 ◽  
Author(s):  
Brian J. Atwell ◽  
Martin L. Henery ◽  
Gordon S. Rogers ◽  
Saman P. Seneweera ◽  
Marie Treadwell ◽  
...  

We report on the relationship between growth, partitioning of shoot biomass and hydraulic development of Eucalyptus tereticornis Sm. grown in glasshouses for six months. Close coordination of stem vascular capacity and shoot architecture is vital for survival of eucalypts, especially as developing trees are increasingly subjected to spasmodic droughts and rising atmospheric CO2 levels. Trees were exposed to constant soil moisture deficits in 45 L pots (30–50% below field capacity), while atmospheric CO2 was raised to 700 μL CO2 L–1 in matched glasshouses using a hierarchical, multi-factorial design. Enrichment with CO2 stimulated shoot growth rates for 12–15 weeks in well-watered trees but after six months of CO2 enrichment, shoot biomasses were not significantly heavier (30% stimulation) in ambient conditions. By contrast, constant drought arrested shoot growth after 20 weeks under ambient conditions, whereas elevated CO2 sustained growth in drought and ultimately doubled the shoot biomass relative to ambient conditions. These growth responses were achieved through an enhancement of lateral branching up to 8-fold due to CO2 enrichment. In spite of larger transpiring canopies, CO2 enrichment also improved the daytime water status of leaves of droughted trees. Stem xylem development was highly regulated, with vessels per unit area and cross sectional area of xylem vessels in stems correlated inversely across all treatments. Furthermore, vessel numbers related to the numbers of leaves on lateral branches, broadly supporting predictions arising from Pipe Model Theory that the area of conducting tissue should correlate with leaf area. Diminished water use of trees in drought coincided with a population of narrower xylem vessels, constraining hydraulic capacity of stems. Commensurate with the positive effects of elevated CO2 on growth, development and leaf water relations of droughted trees, the capacity for long-distance water transport also increased.


Author(s):  
Wenchao Du ◽  
Meiling Xu ◽  
Ying Yin ◽  
Yuanyuan Sun ◽  
Jichun Wu ◽  
...  

2018 ◽  
Vol 10 (3) ◽  
pp. 400-409 ◽  
Author(s):  
Hamid Reza ESHGHIZADEH ◽  
Morteza ZAHEDI ◽  
Samaneh MOHAMMADI

Intraspecific variations in wheat growth responses to elevated CO2 was evaluated using 20 Iranian bread wheat (Triticum aestivum L.) cultivars. The plants were grown in the modified Hoagland nutrient solution at a greenhouse until 35 days of age using two levels of CO2 (~380 and 700 µmol mol–1). The shoot and root dry weights of the wheat cultivars exhibited average enhancements of 17% and 36%, respectively, under elevated CO2. This increase was associated with higher levels of chlorophyll a (25%), chlorophyll b (21%), carotenoid (30%), leaf area (54%) and plant height (49.9%). The leaf area (r = 0.69**), shoot N content (r = 0.62**), plant height (r = 0.60**) and root volume (r = 0.53*) were found to have important roles in dry matter accumulation of tested wheat cultivars under elevated CO2 concentration. However, responses to elevated CO2 were considerably cultivar-dependent. Based on the stress susceptibility index (SSI) and stress tolerance index (STI), the wheat cultivars exhibiting the best response to elevated CO2 content were ‘Sistan’, ‘Navid’, ‘Shiraz’, ‘Sepahan’ and ‘Bahar’, while the ones with poor responses were ‘Omid’, ‘Marun’, ‘Sorkhtokhm’ and ‘Tajan’. The findings from the present experiment showed significant variation among the Iranian wheat cultivars in terms of their responses to elevated air CO2, providing the opportunity to select the most efficient ones for breeding purposes.


1992 ◽  
Vol 40 (5) ◽  
pp. 457 ◽  
Author(s):  
SC Wong ◽  
PE Kriedemann ◽  
GD Farquhar

Four eucalypt species were selected to represent two ecologically disparate groups which would be expected to contrast in seedling vigour and in the nature of growth responses to CO2 × nitrogen supply. Eucalyptus camaldulensis and E. cypellocarpa were taken as examples of fast-growing species with a wide distribution, that develop into large trees. By contrast, E. pauciflora and E. pulverulenta become smaller trees, and show a more limited distribution. Seedlings were established in pots (5 L) of a loamy soil and supplied with nutrient solution containing either 1.2 or 6.0 mM NO3- in both ambient (33 Pa) and CO2-enriched (66 Pa) greenhouses. Analysis of growth response to treatments (2 × 2 factorial) was based on destructive harvest of plants sampled on four occasions over 84 days for E. carnaldulensis and E. cypellocarpa, and 100 days for E. pulverulenta and E. pauciflora. A positive CO2 × N interaction on plant dry mass and leaf area was expressed in all species throughout the study period. In E. carnaldulensis and E. cypellocarpa, plant mass was doubled by high N at 33 Pa CO2, compared with a three to four-fold increase at 66 Pa to reach 34g by final harvest. In E. pulverulenta and E. pauciflora, slower growth resulted in about 50% less mass at a given age, but relative increases due to CO2 and N were of a similar order. A distinction can be made between N and CO2 effects on growth processes as follows. When trees were grown on low N, elevated CO2 increased nitrogen-use efficiency (NUE) at both leaf and whole plant levels. On high N, leaf NUE was increased in E. camaldulensis and E. cypellocarpa, but decreased in E. pulverulenta and E. pauciflora. Whole plant NUE showed no consistent response to elevated CO2 when plants were supplied high N. Net assimilation rate (NAR) was increased by elevated CO2 in all species on either N treatment. Moreover, high N increased NAR under either CO2 treatment in all species. There was a positive N × CO2 interaction on NAR in E. carnaldulensis and E. cypellocarpa, but not in E. pulverulenta and E. pauciflora. Growth indices for E. carnaldulensis and E. cypellocarpa species, and especially E. carnaldulensis, generally exceeded those for E. pulverulenta and E. pauciflora in terms of NAR, leaf NUE, N-enhancement of CO2 effects on leaf area and biomass, and non-structural carbohydrate content of foliage.


1998 ◽  
Vol 25 (3) ◽  
pp. 287 ◽  
Author(s):  
Saman P. Seneweera ◽  
Oula Ghannoum ◽  
Jann Conroy

The hypothesis that shoot growth responses of C4 grasses to elevated CO2 are dependent on shoot water relations was tested using a C4 grass, Panicum coloratum (NAD-ME subtype). Plants were grown for 35 days at CO2 concentrations of 350 or 1000 µL CO2 L-1. Shoot water relations were altered by growing plants in soil which was brought daily to 65, 80 or 100% field capacity (FC) and by maintaining the vapour pressure deficit (VPD) at 0.9 or 2.1 kPa. At 350 µL CO2 L-1, high VPD and lower soil water content depressed shoot dry mass, which declined in parallel at each VPD with decreasing soil water content. The growth depression at high VPD was associated with increased shoot transpiration, whereas at low soil water, leaf water potential was reduced. Elevated CO2 ameliorated the impact of both stresses by decreasing transpiration rates and raising leaf water potential. Consequently, high CO2 approximately doubled shoot mass and leaf length at a VPD of 2.1 kPa and soil water contents of 65 and 80% FC but had no effect on unstressed plants. Water use efficiency was enhanced by elevated CO2 under conditions of stress but this was primarily due to increases in shoot mass. High CO2 had a greater effect on leaf growth parameters than on stem mass. Elevated CO2 increased specific leaf area and leaf area ratio, the latter at high VPD only. We conclude that high CO2 increases shoot growth of C4 grasses by ameliorating the effects of stress induced by either high VPD or low soil moisture. Since these factors limit growth of field-grown C4 grasses, it is likely that their biomass will be enhanced by rising atmospheric CO2 concentrations.


2013 ◽  
Vol 10 (2) ◽  
pp. 1831-1865 ◽  
Author(s):  
K. R. N. Anthony ◽  
G. Diaz-Pulido ◽  
N. Verlinden ◽  
B. Tilbrook ◽  
A. J. Andersson

Abstract. Ocean acidification is a threat to marine ecosystems globally. In shallow-water systems, however, ocean acidification can be masked by benthic carbon fluxes, depending on community composition, seawater residence time, and the magnitude and balance of net community production (pn) and calcification (gn). Here, we examine how six benthic groups from a coral reef environment on Heron Reef (Great Barrier Reef, Australia) contribute to changes in seawater aragonite saturation state (Ωa). Results of flume studies showed a hierarchy of responses across groups, depending on CO2 level, time of day and water flow. At low CO2 (350–450 μatm), macroalgae (Chnoospora implexa), turfs and sand elevated Ωa of the flume water by around 0.10 to 1.20 h−1 – normalised to contributions from 1 m2 of benthos to a 1 m deep water column. The rate of Ωa increase in these groups was doubled under acidification (560–700 μatm) and high flow (35 compared to 8 cm s−1). In contrast, branching corals (Acropora aspera) increased Ωa by 0.25 h−1 at ambient CO2 (350–450 μatm) during the day, but reduced Ωa under acidification and high flow. Nighttime changes in Ωa by corals were highly negative (0.6–0.8 h−1) and exacerbated by acidification. Calcifying macroalgae (Halimeda spp.) raised Ωa by day (by around 0.13 h−1), but lowered Ωa by a similar or higher amount at night. Analyses of carbon flux contributions from four different benthic compositions to the reef water carbon chemistry across Heron Reef flat and lagoon indicated that the net lowering of Ωa by coral-dominated areas can to some extent be countered by long water residence times in neighbouring areas dominated by turfs, macroalgae and potentially sand.


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