Genetic and Physiological Influences on the Alkenone/Alkenoate Versus Growth Temperature Relationship in Emiliania huxleyi and Gephyrocapsa Oceanica

Conte, Maureen H.; Thompson, Anthony; Lesley, David J; Harris, Roger P.

doi:10.1016/s0016-7037(97)00327-x

Cited by 279 publications

(283 citation statements)

References 39 publications

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“…This phenomenon has been previously reported for the northern Mediterranean Sea (Ternois et al, 1997), the central Arabian Sea (Prahl et al, 2000), the subtropical North Pacific (Prahl et al, 2005;Popp et al, 2006) and the subarctic NW Pacific (Harada et al, 2006) and has been attributed to either alkenone production at the thermocline depth (Ternois et al, 1997;Harada et al, 2006) or nutrient deficiency (Popp et al, 2006). Culture experiments have shown a decrease in U K' 37 with nutrient deficiency (Epstein et al, 1998;Conte et al, 1998a;Yamamoto et al, 2000a). Such a physiological response is associated with the increase of the alkenoate/alkenone ratio (Conte et al, 1998a;Yamamoto et al, 2000a).…”

Section: Season and Depth Of Alkenone Productionmentioning

confidence: 66%

“…Culture experiments have shown a decrease in U K' 37 with nutrient deficiency (Epstein et al, 1998;Conte et al, 1998a;Yamamoto et al, 2000a). Such a physiological response is associated with the increase of the alkenoate/alkenone ratio (Conte et al, 1998a;Yamamoto et al, 2000a). In this study, the variation in the alkenoate/alkenone ratio did not correspond to the deviation of U K' 37 -based temperature from SST, suggesting that nutrient deficiency is less likely to explain the deviation.…”

Section: Season and Depth Of Alkenone Productionmentioning

confidence: 99%

“…In this study, the variation in the alkenoate/alkenone ratio did not correspond to the deviation of U K' 37 -based temperature from SST, suggesting that nutrient deficiency is less likely to explain the deviation. Genotypic variations in alkenone producers can also alter the U K' 37 (Volkman et al, 1995;Sawada et al, 1996;Conte et al, 1998a;Yamamoto et al, 2000a). However, a coccolith study showed that Emiliania huxleyi always predominated with a minor contribution from Gephyrocapsa oceanica at this station (Y. Tanaka, unpublished data), although variations at the sub-species level were not investigated; there appears to be little seasonal variation in alkenone producers.…”

Section: Season and Depth Of Alkenone Productionmentioning

confidence: 99%

“…10a). Conte et al (1998a) (Table 7). The NH97 interval did not cover an entire year and did not include the autumn high flux season; thus the organic carbon flux was underestimated.…”

Section: Depth Changes Of Biogenic and Alkenone Sinking Fluxesmentioning

confidence: 99%

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Seasonal and depth variations in molecular and isotopic alkenone composition of sinking particles from the western North Pacific

Yamamoto

Shimamoto²,

Fukuhara³

et al. 2007

Deep Sea Research Part I: Oceanographic Research Papers

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Abstract:Seasonal and depth variations in alkenone flux and molecular and isotopic composition of sinking particles were examined using a 21-month time-series sediment trap experiment at a mooring station WCT-2 (39°N, 147°E) in the mid-latitude NW Pacific to assess the influences of seasonality, production depth, and degradation in the water column on the alkenone unsaturation index U K' 37 . Analysis of the underlying sediments was also conducted to evaluate the effects of alkenone degradation at the 1 water-sediment interface on U K' 37 . Alkenone sinking flux and U K' 37 -based temperature showed strong seasonal variability. Alkenone fluxes were higher from spring to fall than they were from fall to spring. During periods of high alkenone flux, the U K' 37 -based temperatures were lower than the contemporary SSTs, suggesting alkenone production in a well-developed thermocline (shallower than 30m). During low alkenone flux periods, the U K' 37 -based temperatures were nearly constant and were higher than the contemporary SSTs. The nearly constant carbon isotopic ratios of C 37:2 and C 38:2 alkenones suggest that alkenones produced in early fall were suspended in the surface water until sinking. The alkenone sinking flux decreased exponentially with increasing depth. The decreasing trend was enhanced during the periods of high alkenone flux,suggesting that fresh and labile particles sank from spring to fall, while old and stable particles sank from fall to spring. The U K' 37 -based temperature usually increased with increasing depth. The preservation efficiency of alkenones was ~2.7-5.2% at the water-sediment interface. Despite the significant degradation of the alkenones, there was little difference in U K' 37 levels between sinking particles and the surface sediment.

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Section: Season and Depth Of Alkenone Productionmentioning

confidence: 66%

Section: Season and Depth Of Alkenone Productionmentioning

confidence: 99%

Section: Season and Depth Of Alkenone Productionmentioning

confidence: 99%

“…10a). Conte et al (1998a) (Table 7). The NH97 interval did not cover an entire year and did not include the autumn high flux season; thus the organic carbon flux was underestimated.…”

Section: Depth Changes Of Biogenic and Alkenone Sinking Fluxesmentioning

confidence: 99%

See 2 more Smart Citations

Seasonal and depth variations in molecular and isotopic alkenone composition of sinking particles from the western North Pacific

Yamamoto

Shimamoto²,

Fukuhara³

et al. 2007

Deep Sea Research Part I: Oceanographic Research Papers

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“…Secondary effects such as the effect of salinity on the Mg/Ca of foraminifera (Hönisch et al, 2013), or nutrient availability on the Uk'37 recorded by the alkenone producers (Conte et al, 1998), might further effect the recorded proxy signal.…”

Section: Sensor Stagementioning

confidence: 99%

Sedproxy: a forward model for sediment archived climate proxies

Dolman¹,

Laepple²

2018

Preprint

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Abstract. Climate reconstructions based on proxy records recovered from marine sediments, such as alkenone records or geochemical parameters measured on foraminifera, play an important role in our understanding of the climate system. They provide information about the state of the ocean ranging back hundreds to millions of years and form the backbone of paleooceanography.However, there are many sources of uncertainty associated with the signal recovered from sediment archived proxies. These 5 include seasonal or depth habitat biases in the recorded signal, a frequency dependent reduction in the amplitude of the recorded signal due to bioturbation of the sediment, aliasing of high frequency climate variation onto a nominally annual, decadal or centennial resolution signal, and additional sample processing and measurement error introduced when the proxy signal is recovered.Here we present a forward model for sediment archived proxies that jointly models the above processes, so that the magnitude 10 of their separate and combined effects can be investigated.Applications include the interpretation and analysis of uncertainty in existing proxy records, parameter sensitivity analysis to optimize future studies, and the generation of pseudo-proxy records that can be used to test reconstruction methods. We provide examples, such as the simulation of individual foraminifera records, that demonstrate the usefulness of the forward model for paleoclimate studies. The model is implemented as a user-friendly R package, sedproxy, the use of which we hope 15 will contribute to a better understanding of both the limitations and potential of marine sediment proxies to inform about past climate.

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Sea surface temperature variations in the western Mediterranean Sea over the last 20 kyr: A dual‐organic proxy (U ^K′ ₃₇ and LDI) approach

et al. 2014

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A high-resolution sea surface temperature (SST) reconstruction of the western Mediterranean was accomplished using two independent, algae-based molecular organic proxies, i.e., the U K′ 37 index based on long-chain unsaturated ketones and the novel long-chain diol index (LDI) based on the relative abundances of C 28 and C 30 1,13-and 1,15-diols. Two marine records, from the western and eastern Alboran Sea basin, spanning the last 14 and 20 kyr, respectively, were studied. Results from the surface sediments suggest that the two proxies presently reflect seasons with similar SST or simply annual mean SST. Both proxy records reveal the transition from the Last Glacial Maximum to the Holocene in the eastern Alboran Sea with an SST increase of approximately 7°C for U

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Genetic and Physiological Influences on the Alkenone/Alkenoate Versus Growth Temperature Relationship in Emiliania huxleyi and Gephyrocapsa Oceanica

Cited by 279 publications

References 39 publications

Seasonal and depth variations in molecular and isotopic alkenone composition of sinking particles from the western North Pacific

Seasonal and depth variations in molecular and isotopic alkenone composition of sinking particles from the western North Pacific

Sedproxy: a forward model for sediment archived climate proxies

Sea surface temperature variations in the western Mediterranean Sea over the last 20 kyr: A dual‐organic proxy (U ^K′ ₃₇ and LDI) approach

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Genetic and Physiological Influences on the Alkenone/Alkenoate Versus Growth Temperature Relationship in Emiliania huxleyi and Gephyrocapsa Oceanica

Cited by 279 publications

References 39 publications

Seasonal and depth variations in molecular and isotopic alkenone composition of sinking particles from the western North Pacific

Seasonal and depth variations in molecular and isotopic alkenone composition of sinking particles from the western North Pacific

Sedproxy: a forward model for sediment archived climate proxies

Sea surface temperature variations in the western Mediterranean Sea over the last 20 kyr: A dual‐organic proxy (U K′ 37 and LDI) approach

Contact Info

Product

Resources

About

Sea surface temperature variations in the western Mediterranean Sea over the last 20 kyr: A dual‐organic proxy (U ^K′ ₃₇ and LDI) approach