scholarly journals Inter- and intra-specimen variability masks reliable temperature control on shell Mg/Ca ratios in laboratory and field cultured <i>Mytilus edulis</i> and <i>Pecten maximus</i> (bivalvia)

2008 ◽  
Vol 5 (1) ◽  
pp. 531-572 ◽  
Author(s):  
P. S. Freitas ◽  
L. J. Clarke ◽  
H. A. Kennedy ◽  
C. A. Richardson
Keyword(s):  
Mytilus Edulis ◽  
Shell Growth ◽  
Large Degree ◽  
Environmental Variable ◽  
Study Data ◽  
Pecten Maximus ◽  
Bivalve Species ◽  
Ambient Conditions ◽  
Ratio Data ◽  
Temperature Proxy

Abstract. The Mg/Ca ratios of biogenic calcites are commonly seen as a valuable palaeo-proxy for reconstructing past ocean temperatures. The temperature dependence of Mg/Ca ratios in bivalve calcite has been the subject of contradictory observations. The palaeoceanographic use of a geochemical proxy, like Mg/Ca ratios, is dependent on initial, rigorous calibration and validation of relationships between the proxy and the ambient environmental variable to be reconstructed. Shell Mg/Ca ratio data are reported for the calcite of two bivalve species, Mytilus edulis (common mussel) and Pecten maximus (king scallop), for the first time grown in laboratory culturing experiments at controlled and constant aquarium seawater temperatures over a range from ~10 to ~20°C. Furthermore, Mg/Ca ratio data of laboratory-grown and field-grown M. edulis specimens were compared. Only a weak, albeit significant, shell Mg/Ca ratio–temperature relationship was observed in the two bivalve species: M. edulis (r2=0.37, p<0.001 laboratory cultured specimens and (r2=0.50, p<0.001 for field cultured specimens) and P. maximus (r2=0.21, p<0.001, laboratory cultured specimens only). In the two species, shell Mg/Ca ratios also were not found to be controlled by shell growth rate and salinity. Furthermore, measurement of Mg/Ca ratios in the shells of multiple specimens illustrated that a large degree of variability in the measured shell Mg/Ca ratios was significant at the species, inter- and intra-individual shell levels. The study data suggest the use of bivalve calcite Mg/Ca ratios as a reliable, precise and accurate temperature proxy still remains limited, at least in the species studied to date. Such limitations are most likely due to the presence of significant physiological effects on Mg incorporation in bivalve calcite, with such variability differing both within single shells and between shells of the same species that were precipitated under the same ambient conditions.

scholarly journals Inter- and intra-specimen variability masks reliable temperature control on shell Mg/Ca ratios in laboratory- and field-cultured <i>Mytilus edulis</i> and <i>Pecten maximus</i> (bivalvia)

2008 ◽  
Vol 5 (5) ◽  
pp. 1245-1258 ◽  
Author(s):  
P. S. Freitas ◽  
L. J. Clarke ◽  
H. A. Kennedy ◽  
C. A. Richardson
Keyword(s):  
Mytilus Edulis ◽  
Temperature Control ◽  
Environmental Variable ◽  
Pecten Maximus ◽  
Bivalve Species ◽  
Calibration And Validation ◽  
Ratio Data ◽  
The Subject ◽  
Reliable Temperature ◽  
Laboratory Culturing

Abstract. The Mg/Ca ratios of biogenic calcite is commonly seen as a valuable palaeo-proxy for reconstructing past ocean temperatures. The temperature dependence of Mg/Ca ratios in bivalve calcite has been the subject of contradictory observations. The palaeoceanographic use of a geochemical proxy is dependent on initial, rigorous calibration and validation of relationships between the proxy and the ambient environmental variable to be reconstructed. Shell Mg/Ca ratio data are reported for the calcite of two bivalve species, Mytilus edulis (common mussel) and Pecten maximus (king scallop), which were grown in laboratory culturing experiments at controlled and constant aquarium seawater temperatures over a range from ~10 to ~20°C. Furthermore, Mg/Ca ratio data of laboratory- and field-grown M. edulis specimens were compared. Only a weak, albeit significant, shell Mg/Ca ratio–temperature relationship was observed in the two bivalve species: M. edulis (r2=0.37, p

The Effects of Reduced Salinity on the Shell Growth of Small Mytilus Edulis

1984 ◽  
Vol 64 (1) ◽  
pp. 171-182 ◽  
Author(s):  
Patricia C. Almada-Villela
Keyword(s):  
Growth Rate ◽  
Mytilus Edulis ◽  
High Salinity ◽  
Shell Growth ◽  
Experimental Period ◽  
Gradual Decline ◽  
Poor Growth ◽  
Term Response ◽  
Better Than

The shell growth of small coastal Mytilus edulis L. was measured at three different constant low salinities over short periods of time. Growth was significantly depressed in 6·4 and 16‰ S but not in 22·4‰ S. Fluctuating salinities between 0 and 32‰ S depressed growth whether the fluctuations were of sinusoidal or abrupt form. After 1 week of preconditioning to constant 32‰ S the growth of coastal (Bangor) mussels was better than estuarine (Conwy) mussels. However, after two weeks’ preconditioning to 32‰ S the estuarine mussels displayed the best growth. In the fluctuating regime, both coastal and estuarine mussels exhibited poor growth rates. The long-term response of the shell growth of coastal M. edulis was followed over a period of 44 days. Salinities in the range 1·8–9·6‰ S were lethal to the mussels within 10 days. In 12·8 and 16‰ S growth was initially delayed but recovered eventually. There was a gradual decline in the growth rate of the mussels exposed to the higher salinities (19·2–32‰) and an improvement in the growth of the mussels living in lower salinities (12·8 and 16‰) to levels nearly matching that of the high salinity animals by day 37. This suggests that acclimation of the shell growth of M. edulis to salinities in the 12·8–28·8‰ S range was achieved by the mussels during the experimental period.

Growth Inhibition and Recovery in Mussels (Mytilus Edulis) Exposed to Low Copper Concentrations

1985 ◽  
Vol 65 (2) ◽  
pp. 421-431 ◽  
Author(s):  
Keith J. Redpath
Keyword(s):  
Growth Inhibition ◽  
Mytilus Edulis ◽  
Flow System ◽  
Shell Growth ◽  
Experimental Systems ◽  
Through Flow ◽  
Metal Addition

Studies concerned with the sub-lethal aspects of the toxicity of copper to the mussel have, in many cases, been compromised through the use of static experimental systems (see Davenport & Redpath (1984) for review). Manley, Gruffydd & Almada-Villela (1984), using a through flow system, reported a significant reduction in shell growth at a concentration of 10 μg I-1 added copper with recovery after metal addition had ceased. Strömgren (1982) investigated the effects of a series of concentrations of the metal (amongst others) on Mytilus, but there are discrepancies between his results and the work of others which have been fully discussed elsewhere by Davenport and Redpath.

scholarly journals Assessment of soil <i>n</i>-alkane δ<i>D</i> and branched tetraether membrane lipid distributions as tools for paleoelevation reconstruction

2009 ◽  
Vol 6 (12) ◽  
pp. 2799-2807 ◽  
Author(s):  
F. Peterse ◽  
M. T. J. van der Meer ◽  
S. Schouten ◽  
G. Jia ◽  
J. Ossebaar ◽  
...  
Keyword(s):  
Membrane Lipids ◽  
Large Degree ◽  
Membrane Lipid ◽  
Lapse Rate ◽  
Measured Temperature ◽  
Soil N ◽  
Altitude Effect ◽  
Temperature Lapse Rate ◽  
Elevation Changes ◽  
Temperature Proxy

Abstract. δ18O values of pedogenic minerals forming from soil water are commonly used to reconstruct paleoelevation. To circumvent some of the disadvantages of this method, soil n-alkane δD values were recently proposed as a new tool to reconstruct elevation changes, after showing that soil n-alkane δD values track the altitude effect on precipitation δD variations (r2=0.73 along Mt. Gongga, China). To verify the suitability of soil n-alkane δD values as a paleoelevation proxy we measured the δD of soil n-alkanes along Mt. Kilimanjaro (Tanzania). At midslope, soil n-alkane δD values are possibly influenced by the present precipitation belt, causing D-depletion in precipitation, and hence in the soil n-alkanes. Consequently, soil n-alkane δD values do not linearly relate with altitude (r2=0.03), suggesting that, in this case, they can not serve as an unambiguous proxy to infer past elevation changes. In contrast, it was recently shown that the MBT/CBT temperature proxy, which is based on the distribution of branched glycerol dialkyl glycerol tetraether (GDGT) membrane lipids, is linearly related with MAT, and thus altitude (r2=0.77), at Mt. Kilimanjaro. This suggests that this proxy may be more suitable for paleoelevation reconstruction for this region. However, application of the MBT/CBT proxy on the altitude gradient along Mt. Gongga showed that, although the MBT/CBT-derived temperature lapse rate (−5.9°C/1000 m) resembles the measured temperature lapse rate (−6.0°C/1000 m), there is a relatively large degree of scatter (r2=0.55). Our results thus show that both proxies can be subject to relatively large uncertainties in their assessment of past elevation changes, but that a combination of the soil n-alkane δD and MBT/CBT proxies can likely result in a more reliable assessment of paleoelevation.

The effects of temperature on the shell growth of young mytilus edulis L.

1982 ◽  
Vol 59 (2-3) ◽  
pp. 275-288 ◽  
Author(s):  
Patricia C. Almada-Villela ◽  
John Davenport ◽  
Llyr D. Gruffydd
Keyword(s):  
Mytilus Edulis ◽  
Shell Growth ◽  
Effects Of Temperature

Food-Limited Growth of Mytilus edulis L. in Relation to the Benthic Boundary Layer

1985 ◽  
Vol 42 (6) ◽  
pp. 1166-1170 ◽  
Author(s):  
Marcel Fréchette ◽  
Edwin Bourget
Keyword(s):  
Mytilus Edulis ◽  
Shell Growth ◽  
Dry Weight ◽  
Benthic Boundary Layer ◽  
Water Interface ◽  
In Situ Growth ◽  
Limited Growth ◽  
Mussel Bed ◽  
Organic Particles

The hypothesis that depletion of organic particles near the sediment limits the growth of benthic suspension feeders was tested. In situ growth of Mytilus edulis L. was significantly depressed at the sediment–water interface, as compared with growth 1.0 m above the mussel bed, in studies at two shore levels. Flesh dry weight was sensitive to treatment effects, but not shell growth. We conclude that mussels from the bed were food limited.

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