A potential new sea surface temperature proxy based on isomeric highly branched isoprenoid lipid biomarkers: EZ25

Simon T. Belt; Lukas Smik; Katrine Husum; Jochen Knies

doi:10.1016/j.orggeochem.2025.105056

A potential new sea surface temperature proxy based on isomeric highly branched isoprenoid lipid biomarkers: EZ25

Simon T. Belt
, Lukas Smik
, Katrine Husum
, Jochen Knies

School of Geography, Earth and Environmental Sciences

Research output: Contribution to journal › Article › peer-review

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Abstract

Two tri-unsaturated and isomeric (E/Z) highly branched isoprenoid (HBI) diatom lipid biomarkers were quantified in 228 water column samples collected from the English Channel, West Svalbard (Arctic), the Scotia Sea (Southern Ocean) and East Antarctica. We found that the relative amounts of the two HBIs correlate well with water temperatures taken at the time of sampling. Based on these findings and some other HBI data reported previously, we suggest that the proportion of the HBI E-isomer (termed EZ25) may serve as a new proxy for palaeo sea surface temperatures, including in the polar regions. Next steps will involve determination of EZ25 in surface and downcore sediments to ascertain whether the temperature response described herein translates well to the geological record.

Original language	English
Article number	105056
Journal	Organic Geochemistry
Volume	208
DOIs	https://doi.org/10.1016/j.orggeochem.2025.105056
Publication status	Published - 18 Aug 2025

ASJC Scopus subject areas

Geochemistry and Petrology

Keywords

Biomarker
Sea surface temperature
Proxy
Arctic
Antarctic
Highly branched isoprenoid
HBI

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10.1016/j.orggeochem.2025.105056

1-s2.0-S0146638025001299-mainFinal published version, 2.05 MBLicence: CC BY

Cite this

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title = "A potential new sea surface temperature proxy based on isomeric highly branched isoprenoid lipid biomarkers: EZ25",

abstract = "Two tri-unsaturated and isomeric (E/Z) highly branched isoprenoid (HBI) diatom lipid biomarkers were quantified in 228 water column samples collected from the English Channel, West Svalbard (Arctic), the Scotia Sea (Southern Ocean) and East Antarctica. We found that the relative amounts of the two HBIs correlate well with water temperatures taken at the time of sampling. Based on these findings and some other HBI data reported previously, we suggest that the proportion of the HBI E-isomer (termed EZ25) may serve as a new proxy for palaeo sea surface temperatures, including in the polar regions. Next steps will involve determination of EZ25 in surface and downcore sediments to ascertain whether the temperature response described herein translates well to the geological record.",

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doi = "10.1016/j.orggeochem.2025.105056",

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journal = "Organic Geochemistry",

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T1 - A potential new sea surface temperature proxy based on isomeric highly branched isoprenoid lipid biomarkers: EZ25

AU - Belt, Simon T.

AU - Smik, Lukas

AU - Husum, Katrine

AU - Knies, Jochen

PY - 2025/8/18

Y1 - 2025/8/18

N2 - Two tri-unsaturated and isomeric (E/Z) highly branched isoprenoid (HBI) diatom lipid biomarkers were quantified in 228 water column samples collected from the English Channel, West Svalbard (Arctic), the Scotia Sea (Southern Ocean) and East Antarctica. We found that the relative amounts of the two HBIs correlate well with water temperatures taken at the time of sampling. Based on these findings and some other HBI data reported previously, we suggest that the proportion of the HBI E-isomer (termed EZ25) may serve as a new proxy for palaeo sea surface temperatures, including in the polar regions. Next steps will involve determination of EZ25 in surface and downcore sediments to ascertain whether the temperature response described herein translates well to the geological record.

AB - Two tri-unsaturated and isomeric (E/Z) highly branched isoprenoid (HBI) diatom lipid biomarkers were quantified in 228 water column samples collected from the English Channel, West Svalbard (Arctic), the Scotia Sea (Southern Ocean) and East Antarctica. We found that the relative amounts of the two HBIs correlate well with water temperatures taken at the time of sampling. Based on these findings and some other HBI data reported previously, we suggest that the proportion of the HBI E-isomer (termed EZ25) may serve as a new proxy for palaeo sea surface temperatures, including in the polar regions. Next steps will involve determination of EZ25 in surface and downcore sediments to ascertain whether the temperature response described herein translates well to the geological record.

KW - Biomarker

KW - Sea surface temperature

KW - Proxy

KW - Arctic

KW - Antarctic

KW - Highly branched isoprenoid

KW - HBI

UR - https://doi.org/10.1016/j.orggeochem.2025.105056

UR - https://pearl.plymouth.ac.uk/gees-research/1528/

U2 - 10.1016/j.orggeochem.2025.105056

DO - 10.1016/j.orggeochem.2025.105056

M3 - Article

SN - 0146-6380

VL - 208

JO - Organic Geochemistry

JF - Organic Geochemistry

M1 - 105056

ER -

A potential new sea surface temperature proxy based on isomeric highly branched isoprenoid lipid biomarkers: EZ25

Abstract

ASJC Scopus subject areas

Keywords

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