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8th Annual
Biogeochemistry
Conference
at
The Marine Station
Plymouth
Monday 19th December 2016
Book of Abstracts
8th Annual Conference
Welcome to the 8th Annual Biogeochemistry Conference, hosted for the second
time at Plymouth University’s Marine Station.
This year we have fifteen presentations that demonstrate the diversity and
quality of research within our research community. We also warmly welcome Dr
Ming-Xi Yang from Plymouth Marine Laboratory. Dr Yang’s research straddles
the boundary between chemical oceanography and atmospheric chemistry, and
he will be giving the keynote presentation at the end of the day.
The sessions have been grouped around the following themes:
(i)
Environmental Anthropogenic Contaminants
(ii)
The Soil and Water Environment
(iii) The Ocean and Atmosphere
(iv) Analytical Challenges and Biomarkers
The presentations, as you can see, stride the land – river – estuary - sea
continuum.
As usual there is a mix of reports on environmental biogeochemistry and
analytical challenges, to be faced or being overcome. Both aspects reflect our
holistic approach to environmental science.
We trust the day will provide an excellent opportunity for everyone to see and
hear what we do across the group, and to provide useful feedback via the
discussion sessions.
Best wishes,
Angie Milne & Antony Birchill
The BGC organising committee
Order of Presentations
9.30 – 9.55
Arrival and setup
9.55 – 10.00
Opening to the BGC Conference
By Prof Paul Worsfold
Session I: Environmental Anthropogenic Contaminants
10.00 – 10.15
Kat Lees
10.15 – 10.30
Simone Bagnis
10.30 – 10.45
Yann Aminot
10.45 – 11.00
Maya Al-Sid-Cheikh
11.00 – 11.30
Practicalities of using the ‘routine’ risk
assessment for pharmaceuticals in soils
irrigated with wastewater
Understanding the fate of active
pharmaceutical compounds in surface waters
receiving poorly or untreated sewage effluent
and the development of appropriate
environmental risk assessment approaches
Sources and reactivity of C60-fullerenes
in the environment: preliminary investigations
Journey into the infinitely small
Break
Session II: Soil and Water Environment
11.30 – 11.45
Mary Lane
11.45 – 12.00
Lauren Dawson
12.00 – 12.15
Nadia Jebril
12.15 – 12.30
Vanessa Huml
12.30 – 13.45
Chair: Hayley
Buffet Lunch
Chair: Yann
Restoring heathlands after mineral extraction:
exploring processes and patterns
Characterising the chemistry and ecology of
the West Dart River before trial calcium
carbonate dosing for pH mitigation
Elemental analysis of metal contaminated
soils using ICP-MS, XRF techniques and
CHNS analyser
Comparison of functional versus neutral
genetic markers as a tool in conservation
biology
Session IV: The Ocean and Atmosphere
13.45 – 14.00
Sov Atkinson
14.00 – 14.15
Caroline White
14.15 – 14.30
Antony Birchill
14.30 – 14.45
Nora Hartner
14.45 – 15.15
Chair: Angie
A one-year seasonal study of trace metal
concentrations in coastal atmospheric
aerosols from Penlee Point Atmospheric
Observatory, Cornwall, UK
Quantifying atmospheric organic nitrogen in
aerosols from Penlee Point Atmospheric
Observatory, Cornwall, UK
Seasonal cycling of soluble, colloidal and
particulate iron in the Celtic Sea
The distribution of dissolved iron over the
Shelf slope of the Celtic Sea
Break
Session V: Analytical Challenges and Biomarkers
15.15– 15.30
Deniz Koseoglu
15.30 – 15.45
Hayley Manners
15.45 – 16.00
Will Robson
Chair: Lukas
Evaluation of highly-branched isoprenoid
biomarkers against the modern sea ice
regime and hydrography in the Barents
Sea
Selective preservation of Amides in tephra
layers
Poles apart: Characterisation of the polar
constituents of crude oil
Keynote Speaker
16.00 – 16.30
16.30
Mingxi Yang
What is that salty breath of ‘fresh air?’
Closing of the BGC Conference
By Prof Steve Rowland
19.30
Conference meal at The Village, Barbican
SESSION I
Environmental Anthropogenic
Contaminants
Practicalities of using the ‘routine’ risk assessment for
pharmaceuticals in soils irrigated with wastewater
Katherine Lees1, Mark Fitzsimons1, Jason Snape2, Alan Tappin1 and Sean Comber11
1Biogeochemistry
Research Centre, School of Geography, Earth and Environmental Sciences, Plymouth
University, Plymouth, PL4 8AA.
2AstraZeneca Global Environment, AstraZeneca, Cambridge, UK
Wastewater re-used for irrigation is currently not included in environmental risk
assessments for active pharmaceutical ingredients (APIs) in soils. The addition of
wastewater to soils changes the organic content and can increase the pH of soils,
which will have an impact on the fate of any ionisable APIs introduced during the
irrigation process. Terrestrial risk assessments are also not conducted for APIs which
have an organic carbon partitioning coefficient < 10 000 L/kgOC; so not only is irrigation
excluded there is also a lack of risk assessment data for polar APIs.
The standard method for testing the sorption behaviour of chemicals in soil is either the
OECD 106 method or the equivalent US EPA method. The OECD 106 method was
used to characterise the fate of three ionisable APIs (propranolol, naproxen and
ofloxacin) in two soil matrices (loam and sandy loam) by shaking a soil solution spiked
with the APIs. Loss of the APIs from solution was measured. These experiments
identified challenges associated with the ability of this standard method to determine
the environmental fate of ionisable APIs.
The following challenges associated with the OECD 106 method will be discussed:





Selection of a filter membrane with suitable pore size while preventing retention
of analyte
The soil : solution ratio can affect the experimental pH, partitioning ehavior,
ionic strength and chemical composition of soil solutions
Degradation of the API during the experiment
Impact of wastewater addition on the physical-chemical properties of the soil
solution
Do the suggested concentrations of API spikes offer appropriate environmental
simulation?
Understanding the fate of active pharmaceutical compounds in
surface waters receiving poorly or untreated sewage effluent and the
development of appropriate environmental risk assessment
approaches
Simone Bagnis1, Mark Fitzsimons1, Jason Snape2, Alan Tappin1 and Sean Comber1
1Biogeochemistry
Research Centre, School of Geography, Earth and Environmental Sciences, Plymouth
University, Plymouth, PL4 8AA.UK
2AstraZeneca Global Environment, AstraZeneca, Cambridge, UK.
Active pharmaceutical compounds (API’s) have been classified as emerging
contaminants, and their introduction in the environment might pose risks to ecosystems.
The main source of pharmaceuticals in the environment is human use and excretion or
the improper of unused mediation to the sewerage system. In wastewater treatment
works the lack of efficient removal of some pharmaceuticals, combined with pseudopersistence, results in their presence in surface waters. As patient access to medicines
increases in developing countries the environmental concentration of pharmaceuticals
has the potential to be higher than in developed countries if the level of wastewater and
drinking water treatment does not also increase.
Untreated wastewater enters the environment via discharge into surface waters
resulting in a downstream area characterized by high pollution, named “impact zone”.
Characterization of the environmental risk posed by pharmaceuticals in such an area is
challenging since the formal protocol for environmental risk assessment was developed
for environmental conditions largely different from the ones encountered in the impact
zone; High levels of BOD, ammonia, and other potential toxicants exist in combination
with low concentrations of dissolved oxygen, meaning that there is an absence of
traditional species used for toxicological endpoints. Therefore, the calculation of
predicted environmental concentrations (PEC) in such conditions is not relevant.
The aim of the research is to obtain a comprehensive overview of the gaps regarding
the fate of pharmaceuticals in aquatic environment initially starting with an extensive
literature review of available data for (1) occurrence, (2) degradation rates, (3)
partitioning to dissolved organic matter, colloids, suspended solid matter and
sediments, and (4) relevant endpoints. This will inform experimental research aimed at
gaining data about partitioning and degradation of selected pharmaceuticals in the
impact zone at varying dilutions, and determination of proper endpoints.
The information obtained will be used to develop an environmental risk assessment
approach for impact zones, as only with more accurate exposure concentrations and
impact data can the risks to the aquatic environment of APIs be quantified.
Sources and reactivity of C60-fullerenes in the environment:
preliminary investigations
Yann Aminot1, Josep Sanchís2, Marinella Farré2, Damià Barceló2 and James W.
Readman1
1Biogeochemistry
2Institute
Research Centre, Plymouth University, Plymouth, UK
of Environmental Assessment and Water Research (IDAEA), Barcelona, Catalonia, Spain
Since their discovery in 1985 by Sir Harold W. Kroto and colleagues, fullerenes have
attracted ever-increasing attention and created numerous applications in all fields of
chemistry and physicochemistry (optics, electronics, cosmetics, biomedicine…). As
engineered nanomaterials, fullerenes are expected to be released into the environment
through industrial and urban wastewaters and/or landfills. In addition, incidental
formation of C60-fullerenes from combustion sources has recently been established in
the exhausts of common fuels. Natural emission pathways have also been
hypothesized with various identifications of “fullerene-like” materials in geological
samples. As a consequence of their release, C60s have been detected in river water,
surface sediments and soils as well as on aerosols from the sea atmosphere. After
discharge in the environment, the fate of fullerenes is largely unexplored. In water
bodies, the hydrophobic fullerenes can form stable aqueous nano-suspensions or
adsorb onto particulate matter. Further degradation processes may involve
hydroxylation, oxidation or other surface functionalization but remain largely speculative
to date. However, the natural occurrence of C60-O derivatives could be of potential
concern as their toxicity remains unknown. It has been shown that oxygenated byproducts of organic compounds can exhibit much higher toxicity than their parent
compounds, e.g. oxygenated polycyclic aromatic hydrocarbons.
In the present work, we developed and validated an analytical method based on
LCHRMS for the quantification of trace levels of fullerenes and their major oxidation byproducts. We also report for the first time the environmental occurrence of fullerenes
and some fullerene-oxides on urban aerosols and in river water. The conditions of
formation of these oxidation products were also investigated. Incubation experiments
were conducted under environmentally realistic conditions to evaluate the influence of
ionic strength, organic matter, pH and exposure to light on the oxidation of C60fullerenes.
Journey into the infinitely small
M. Al-Sid-Cheikh1,2, S. J. Rowland2 and R. Thompson1
1Marine
Biology and Ecology Research Centre (MBERC), School of Marine Sciences and Engineering,
University of Plymouth, Plymouth, PL4 8AA, United-Kingdom.
2Biogeochemistry Research Centre, School of Geography, Earth and Environmental Sciences, University
of Plymouth, Plymouth, PL4 8AA, United-Kingdom.
The awareness campaign about plastic pollution in oceans is fully backed by the UK
government with recent initiatives such as the ban microbeads (i.e. d<5mm) from
cosmetics by end of 2017. However, characterization of microplastics (MPs) and their
fate in environment is still a critical issue to assess their long-term impact on
environmental systems. Cózar et al. (2014)1 highlighted a loss of about 12 % of plastic
from the estimated discharged amount into the environment. This important gap might
be explained by a further fragmentation of MPs in nanoplastics (i.e. d<100nm, NPs) that
are not yet measurable by the available analytical chemistry techniques. Detection
methods of NPs are still in an early stage of development and, to date, no nanoplastics
have yet been detected in natural aquatic systems. Here, I will present different
techniques, and their inherent challenges, that are promising to detect NPs and to track
them in realistic environmental concentrations. Amongst them, I will present our recent
works and orientations in order to i) detect and characterize NPs, ii) assess their
interactions with other co-contaminants, and iii) follow the bioaccumulation of NPs and
their potential presence in the food web. By developing these techniques, the main goal
of our project is to assess the real risks of NPs in plausible environmental
concentrations.
1. Cózar A, Echevarría F, González-Gordillo JI, et al (2014) Plastic debris in the open ocean. Proc Natl
Acad Sci 111 :10239–10244.
SESSION II
Soil and Water Environment
Restoring Heathlands after mineral extraction: exploring processes
and patterns
M. Lane1, J. Ellis1, P. Lunt1, M. Hanley2 and M. Knight3
1Biogeochemistry
Research Centre, School of Geography, Earth and Environmental Sciences, Plymouth
University, Plymouth, PL4 8AA.
2School of Biological Sciences, University of Plymouth, Plymouth, PL4 8AA, UK
Restoring land after mineral extraction to fulfil a Biodiversity Action Plan (BAP) habitat is
a complex process. Creating the right abiotic soil conditions, soil community and plant
community may ensure a successful outcome. Based on data collected on-site and
existing literature, a large-scale field trial has been set up to examine the effect of
increased nutrients, organic matter and the reintroduction of ericoid mycorrhizae fungi
(ERM) on the development of lowland heath. The trial has been set to capture the
autumn germination of the native grasses and the vernalisation of spring germinating
ericoids. The plant community and soil conditions will be monitored annually until 2019.
The experiment was set up in 2016, and results are not expected till summer 2017 at
the earliest. The experimental design will be presented and discussed.
Characterising the chemistry and ecology of the West Dart River
before trial calcium carbonate dosing for pH mitigation.
L. Dawson1, S. Comber1, R. Sandford1, A. Tappin1, and B. Stockley2
1Biogeochemistry
Research Centre, School of Geography, Earth and Environmental Sciences, Plymouth
University, Plymouth, PL4 8AA.
2
Westcountry Rivers Trust, Rain Charm House, Kyl Cober Parc, Stoke Climsland, Callington PL17 8PH .
The West Dart River is failing under the Water Framework Directive (WFD) for pH,
largely due to anthropogenic influences with unlikely natural recovery. A trial program of
calcium carbonate (CaCO3) addition to the West Dart River is being undertaken this
winter in order to raise pH with the overall aim 0f exploring if CaCO3 application can
prevent pH troughs from dipping below levels biologically relevant to salmon survival
rates (c. <pH 5.5) and assessing any changes in diatom, macro-invertebrate and
macro-algal biological assemblages of the test site against recognised biotic indices.
Full characterisation of the chemistry and ecology of the river will be presented along
with modelling and data on the expected chemical effects of the trial. Hypotheses on
the ecological effects, based off of similar studies in Wales, will also be discussed.
Elemental analysis of metal contaminated soils using ICP-MS, XRF
techniques and CHNS analyser
Nadia Jebril1, Richard Boden1 and Charlotte Braungardt2
2School
1School of Biological Sciences, Plymouth University
of Geography, Earth and Environmental Sciences, Plymouth University
The contamination of soil with heavy metals in Dartmoor, Devon, Southwest England
and UK was well-known due to the mining activities. Therefore, the heavy metal levels
of this soil were investigated. Samples from Bag Tor mine and Hay Tor quarry areas
were collected and analysed. Inductively coupled plasma-mass spectrometry (ICP-MS)
and Energy X-Ray Fluorescence (WXRF) techniques were used to estimate the heavy
metal levels. H, N, S, Total Carbon (TC), Total Organic Carbon (TOC) and Total
Inorganic Carbon (TIC) were estimated in these soils using CHN analyser. Procedural
blanks, standard solutions and certificate reference materials were used to verify
precision and accuracy. This work was aimed to find out the occurrence methods for
determination of heavy metal concentrations in the soil composition which is part of the
project of “Heavy Metal Biogeochemistry and Removal by Microbial Biotechnologies”
The role of genetics in conservation biology with particular emphasis
on management of European grayling (Thymallus thymallus)
V.Huml1,2, R.Sen2, E.Harris2, M.Taylor3 and J.S.Ellis1
1Biogeochemistry
Research Centre, School of Geography, Earth and Environmental Sciences, Plymouth
University, Plymouth, PL4 8AA.
2Manchester Metropolitan University,
3University of East Anglia
Global scale ecosystem alteration and current rates of species extinction make the
maintenance of biodiversity one of the major challenges we and future generations
face. Genetic diversity is a key parameter for the ability of a species to persist and to
adapt to environmental change. The assessment and preservation of genetic diversity
is therefore of high relevance in conservation biology. Here, data regarding how genetic
research can help to inform decisions for management of European grayling (Thymallus
thymallus) in the UK will be presented. As a species of great socioeconomic value, it is
primarily managed through supplementing wild populations with hatchery-reared fish
(‘stocking’). This study is the first to characterize functional genetic variation at a suite of
immune genes within the Major Histocompatibility complex (MHC) in grayling and to
assess the effect of stocking on immune genetic variation. I will show how directly
targeting functional genes, involved in evolutionary processes, can improve sensitivity
of results in comparison to traditionally used non-functional ‘neutral’ markers, which
continue to be the method of choice in population genetic surveys that aim to inform
species conservation. Population clustering based on genetic distance mainly followed
the neutral predictions, so that the assignment of management units is consistent for
immune genetic markers. However, no measurement of genetic diversity correlated
between MHC and neutral markers, highlighting that management decisions based on
the latter are insufficiently informed. Significantly lower levels of genetic diversity for
both ‘introduced’ and ‘native stocked’ populations in comparison to native populations
were only evident from MHC markers. This study adds to the increasing demand of
including ecologically meaningful genetic markers for the information and assessment
of management decisions and raises further doubt on the efficiency of stocking as a
management strategy in supporting long-term viable populations.
SESSION III
The Ocean and Atmosphere
A one-year seasonal study of trace metal concentrations in coastal
atmospheric aerosols from Penlee Point Atmospheric Observatory,
Cornwall, UK.
S. Atkinson1, M. C. Lohan2, P. J. Worsfold1, A. Milne1, M. Yang3, T. Bell3
and S. J.Ussher1
1Biogeochemistry
Research Centre, School of Geography, Earth and Environmental Sciences, Plymouth
University, Plymouth, PL4 8AA. UK
2National Oceanography Centre, University of Southampton, Waterfront Campus
European Way, Southampton, SO14 3ZH, UK
3Plymouth Marine Laboratory, Prospect Place, the Hoe, Plymouth, PL1 3DH, UK
Atmospheric aerosol samples were collected from February 2015 to April 2016 at
Penlee Point Atmospheric Observatory (PPAO) in order to observe the seasonal
variability in trace element concentrations. PPAO is situated in a busy shipping area,
at the mouth of Plymouth Sound and is in close proximity to the shelf sea time series
stations, L4 and E1, part of the Western Channel Observatory. This location is ideally
placed for collecting aerosols from different source regions. Southwesterly winds
transport relatively clean marine derived air masses from the North Atlantic. In
contrast, air masses carried by wind from the north round to the southeast may be
contaminated by anthropogenic activities such as emissions from ships, ferries and
city traffic/industry. The aim of this study was to observe the impact of both local
activities and long range dust transport on trace element concentrations in the
aerosol samples collected.
Weekly 24 h aerosol samples were collected in order to determine the concentration of
crustal-derived elements (AI, Fe, Mn, Cu and Co) and trace metals of anthropogenic
origin (Cd, Pb, Ni, V & Zn). Samples were leached with 100 mL UHP water (18.2
Mcm), followed by complete digested with HF/HNO3 and analysed using ICP-MS, to
obtained the soluble fractions and total concentration. The results were compared with
local wind data and air mass back trajectories and demonstrate the variability in
atmospheric deposition of trace metals to the surface ocean at the coastal site.
Furthermore, there is a strong relationship between reported long range dust events
(e.g. from continental air masses) and the concentrations of particular trace elements,
e.g. Fe vs Al, and a relationship between concentrations of elements more indicative of
anthropogenic activities (e.g. V & Ni) such as shipping traffic.
Quantifying Atmospheric Organic Nitrogen in Aerosols from Penlee
Point Atmospheric Observatory, Cornwall, UK.
Caroline White1, Mark Fitzsimons1, Tom Bell2 and Simon Ussher1
1Biogeochemistry
Research Centre, School of Geography, Earth and Environmental Sciences, Plymouth
University, Plymouth, PL4 8AA. UK
2Plymouth Marine Laboratory, Prospect Place, the Hoe, Plymouth, PL1 3DH, UK
Atmospheric organic nitrogen aerosols represent an important but frequently
unquantified fraction of potentially bioavailable atmospheric nitrogen deposited into the
surface ocean. It can have both anthropogenic and natural sources, and exists in
soluble (WSON) and insoluble (WION) forms. Compared with inorganic nitrogen
species (NO3-, NO2- & NH4+), WSON represents a significant fraction (average 10-35%)
of the total soluble nitrogen (TSN) in aerosols. In contrast, WION represents >99% total
insoluble nitrogen in aerosols and often a large fraction of total nitrogen (TN) in
aerosols, when the more refractory particulate phase is included.
The WSON and WION fractions are often uncharacterised in aerosols. Total organic
nitrogen in aerosols is most commonly determined indirectly from the difference
between TSN and total inorganic nitrogen (TIN) concentrations (e.g. WSON = TSN –
TIN). However, indirect calculations of this kind mean that error associated with each
component in the calculation is combined, which leads to WSON estimates with high
uncertainties, and often negative values. As a consequence, data for atmospheric
organic nitrogen is globally limited, and predominately associated with cruise data or
‘clean’ sector marine air mass observatories (e.g. Tudor Hill, Bermuda), where TIN
concentrations are relatively low.
This presentation will focus on observations from Penlee Point Atmospheric
Observatory (PPAO), situated upon the Rame Head peninsula (SE Cornwall, UK), a
site well placed for sampling of aerosols carried by air masses with both a marine and
continental source. Data collected from PPAO between February and June 2015
demonstrated the variation in TIN concentrations, with relation to different air mass
sources. However, estimates for WSON clearly highlight the problem associated with
accumulative error where TIN concentrations are relatively high. Subsequent method
development has focused on pre-analysis treatments to improve the reliability of WSON
measurements in such samples and initial data are presented.
Seasonal cycling of soluble, colloidal and particulate iron in the Celtic
Sea
A.J Birchill1, A. Milne1, S.J Ussher1, P.J Worsfold1 and M.C Lohan2
1Biogeochemistry
Research Centre, School of Geography, Earth and Environmental Sciences, Plymouth
University, Plymouth, PL4 8AA. UK
2School of Ocean and Earth Science, University of Southampton, National Oceanography Centre,
European Way, Southampton, SO14 3ZH, UK
Shelf systems are important environments that support 10-20% global oceanic primary
production and fuel fisheries supporting 90% of the global catch. Iron (Fe) is an
essential micronutrient for all organisms and plays a pivotal role in the functioning of
marine ecosystems and the carbon cycle. However, the seasonal cycling of Fe in shelf
systems is poorly understood. Here, we report the first seasonal study (2014-15) of size
fractionated dissolved Fe (dFe); separated into soluble Fe (<0.02 µm, sFe) and colloidal
Fe (0.02-0.2 µm, cFe), total dissolvable Fe (unfiltered) as well as particulate Fe (>0.4
µm, pFe) fractions in the shelf system of the Celtic Sea.
Our results showed a clear seasonal cycle of dissolved and particulate Fe phases,
which, were strongly correlated (r2=>0.9) suggesting a dynamic exchange between the
phases through adsorption/desorption processes. dFe and pFe were homogenously
distributed in early spring due to winter mixing where dFe typically comprised 50-60%
cFe. During the spring bloom, depletion of both dFe (<0.2 nM) and pFe was observed in
the surface mixed layer, suggesting biological uptake and/or scavenging of sFe and
cFe, whilst the developing thermocline prevented Fe rich re-suspended sediments
reaching surface waters. Throughout summer and autumn ongoing stratification
prevented resupply of Fe from below the thermocline to surface waters. This, coupled
with biological drawdown in surface waters, resulted in limiting concentrations of dFe
(<0.2 nM). Below the thermocline dFe increased from spring to autumn due to
remineralisation and was predominantly colloidal (60-80%). This study shows for the
first time a clear remineralisation signal in dFe and reflects the dynamic seasonal
cycling of Fe within a stratified shelf system, where surface dFe reach concentrations
that could affect primary productivity. These data also allow us to identify and model the
key processes controlling dFe concentrations in shelf systems.
The distribution of dissolved Fe over the shelf slope of the Celtic Sea.
N.T Hartner1,2, A.J Birchill1, S.J Ussher1, A. Milne1, M.C Lohan3, P.J Worsfold1 and
K. Leopold2
1Biogeochemistry
Research Centre, School of Geography, Earth and Environmental Sciences, Plymouth
University, Plymouth, PL4 8AA, UK
2Institute of Analytical and Bioanalytical Chemistry, Ulm University, 89081 Ulm, Germany
3School of Ocean and Earth Science, University of Southampton, National Oceanography Centre,
European Way, Southampton, SO14 3ZH, UK
Iron (Fe) is an essential micronutrient for phytoplankton growth and is known to limit
primary production in 20-40% of the ocean. Because of its low solubility in oxygenated
seawater and its short residence time in surface seawater (< 1 year), dissolved Fe (dFe;
< 0.2 µm) concentrations are closely related to its supply. Shelf breaks are highly
productive, and are regions of dFe export to the open ocean. To improve the
understanding of dFe transport, and cycling within these important regions, two vertical
transects over the Celtic Sea shelf break were sampled in July 2015 and dFe
concentrations determined by flow-injection chemiluminescence.
This revealed a consistent sub-surface minimum of dFe in the upper 100 m of the water
column with concentrations typically < 0.15 nM. Comparable concentrations have been
found to limit the growth of phytoplankton in other regions (e.g. Southern Ocean).
Therefore, it is hypothesised that the primary production in summer can be co-limited by
dFe, nitrate, and light availability over the Celtic Sea shelf break.
In terms of dFe transportation from the shelf break, distinct nepheloid layers were
detected at depths of 500-900 m in both transects and corresponded with elevated dFe
concentrations (0.9 – 1.9 nM). Nepheloid layers are common features of physically
dynamic shelf break systems and our results suggest they are important conduits for
the supply of dFe to the ocean interior.
SESSION IV
Analytical Challenges and Biomarkers
Evaluation of Highly-Branched Isoprenoid biomarkers against the
modern sea ice regime and hydrography in the Barents Sea
Deniz Koseoglu1, Simon T. Belt1 and Jochen Knies2
1Petroleum
2Centre
and Environmental Geochemistry Group (PEGG), Plymouth University, UK
for Arctic Gas Hydrate, Environment and Climate, Arctic University of Norway, Norway
The Arctic ice cover regulates the global oceanic circulation by contributing to the
formation of deep water, controls the heat budget of the underlying ocean and the
surrounding atmosphere by virtue of its high reflectivity. Further, ice serves as a habitat
to a vast range of species at all trophic levels, from microalgae to the polar bear, and
drives many of the biochemical processes in the Arctic 1. As a result, sea ice is a prime
indicator of climate change. The global temperature warming of over 0.87°C since the
1950s is accompanied by a decline of sea ice extent and thickness unprecedented
within the instrumental record (ca.160 years2). Ice decline has important implications for
global oceanographic regimes, atmospheric heat circulation, food webs, and human
activities3. The Barents Sea holds a unique position in the Arctic Continental Shelf due
to direct inflow of Atlantic Water that supplies 50% of the winter heat flux in the Arctic
Ocean. The complex zonal hydrography, high primary productivity, and seasonal sea
ice cover highlight the suitability of the Barents Sea for investigation of recent and past
circum-Arctic climate4.
The ≈40-year record of satellite-derived sea ice extent5 does not allow for assessment
of climate variability over geologic time scales, and reconstruction of past sea ice
variability is crucial for understanding the implications of modern trends and improving
sea ice forecasts. Over the last decade, a C25 highly-branched isoprenoid (HBI)
biomarker, designated IP25, was identified as a direct proxy for seasonal Arctic sea ice,
and has been used to map the recent sea ice extent and reconstruct past variability6.
The spatial distribution of various HBI biomarkers and their relationship to modern
climate of the Barents Sea will be discussed. Preliminary results of HBI variability in a
sediment core encompassing the Late Weichselian glaciation will be presented.
1.
2.
3.
4.
5.
6.
M. Vancoppenolle et al. (2013), Quaternary Science Reviews 79: 207-230.
J.E. Walsh et al. (2016), Geographical Review, doi:10.1111/j.1931-0846.2016.12195.x
W.N. Meier et al. (2014), Reviews of Geophysics 51: 185-217.
L.H. Smedsrud et al. (2013), Reviews of Geophysics 51: 415-449.
H. Eicken (2013), Nature 497: 431-433.
S.T. Belt and J. Müller (2013), Quaternary Science Reviews 79: 9-25.
Selective preservation of Amides in tephra layers
Hayley R. Manners 1,2, Martin R. Palmer 2, Tom M. Gernon 2, Paul A. Sutton 1,
Steve J. Rowland 1 and Jim McManus3
1Biogeochemistry
Research Centre, University of Plymouth, Drake Circus, Plymouth, PL4 8AA, UK
of Ocean and Earth Sciences, University of Southampton, National Oceanography Centre,
Waterfront campus, Southampton, SO14 3ZH, UK.
3Bigelow Laboratory for Ocean Sciences, 60 Bigelow Drive, P.O. Box 380, East Boothbay, ME 04544
2School
Volcanic eruptions eject large amounts of fine-grained material, known as tephra, into
the atmosphere. Tephra forms distinct layers when it falls to the surface (Lowe 2011)
and is highly reactive when it comes into contact with sea water. In the marine
environment, coupled electron transfer reactions lead to oxidation of Fe II on the tephra
surface and rapid depletion of sediment pore waters in dissolved O 2, and surface-bound
FeII induces chemical catalysis of nitrate reduction (Haeckel et al. 2012; Hembury et al.
2012; Ottley et al. 1997).
Diagenesis of tephra also generates reactive Feoxyhydroxide colloids which disperse into the surrounding environment (Homoky et al.
2011). Thus, the chemical and redox gradients generated by tephra diagenesis may
serve as energy sources for autotrophic microbiological communities, and/or an
overlooked sink for organic carbon preservation. Current work being undertaken at the
Universities of Southampton and Plymouth suggests that tephra layers up to 4 million
years old, collected offshore the volcanic island of Montserrat, contain a unique organic
chemical signature, in the form of preserved amide and sulphonamide compounds.
These compounds may either be indicative of such microbial community activity, or
demonstrate enhanced preservation of such organic compounds is plausible in tephra
layers. This presentation will outline the current state of the research and invites
discussion going forward on the interpretation of current data.
Lowe, D. J. Tephrochronology and its application: A review. Quat. Geochronol. 6, 107-153 (2011).
Haeckel, M., van Beusekom, J., Wiesner, M. G. & König, I. The impact of the 1991 Mount Pinatubo
tephra fallout on the geochemical environment of the deep-sea sediments in the South China Sea.
Earth Planet. Sci. Lett. 193, 151-166 (2001).
Hembury, D. J., Palmer, M.R., Fones, G.R., Mills, R.A., Marsh, R. & Jones, M.T. Uptake of dissolved
oxygen during marine diagenesis of fresh volcanic material. Geochim. Cosmochim. Acta 84, 353-368
(2012).
Ottley, C. J., Davison, W. & Edmunds, W. M. Chemical catalysis of nitrate reduction by iron (II). Geochim.
Cosmochim. Acta 61, 1819-1828 (1997).
Homoky, W. B., Hembury, D.J., Hepburn, L.E., Mills, R.A., Statham, P.J., Fones, G.R. & Palmer, M.R.
Iron and manganese diagenesis in deep sea volcanogenic sediments and the origins of pore water
colloids. Geochim. Cosmochim. Acta 75, 5032-5048 (2011).
Poles Apart: Characterisation of the Polar Constituents of Crude Oil
William J. Robson1, C. Anthony Lewis1, Paul Sutton1, Neil Chilcott2, and Steven J.
Rowland1
1PEGG,
Biogeochemistry Research Centre, Plymouth University, UK
2Kernow Analytical Technology, Cornwall, UK
Information on the heteroatom-containing (nitrogen, sulphur, and oxygen) classes found
in petroleum is of key importance when considering industrial and environmental issues
associated with crude oil production. For instance, increased corrosion of refining
equipment, poisoning of catalysts, and blockages, both in oil transportation pipelines
and in production wells, is often attributed to the more ‘polar’, heteroatom containing
components.
The research presented here attempts to improve on present methods of identification
and measurement of the ‘polar’ compounds of crude oils. To this end, initial work has
focused on development of a comprehensive separation scheme designed to facilitate
the isolation of fractions of various polar compound classes.
This separation scheme was validated by separating a unique ‘in-house’ mixture of oilrelevant ‘polar’ compounds, consisting of 26 compounds chosen to represent
heteroatom containing compound classes known to be present in crude oils. The
authentic compounds were tracked quantitatively through the separation steps and their
final locations within the resultant fractions of the scheme, determined. As a result, the
location of various compound classes within the scheme could be predicted with
increased confidence.
A number of crude oils were then examined by the refined scheme, with and without
spiking with the reference mixture. Multiple separations on a variety of stationary
phases resulted in the collection of a number of fractions of varying composition. For
example, separation of acid and base compounds was facilitated by use of ion
exchange chromatography. Lower polarity compounds being separated by more
traditional silica gel chromatography.
Finally, analysis of the fractions by multidimensional comprehensive gas
chromatography-mass spectrometry (GC×GC-MS) and liquid chromatography-orbitrap
mass spectrometry (LC-MS) facilitated identification of a wide variety of previously
identified heteroatom-containing ‘polar’ compounds and many novel compounds.
Keynote Presentation
What’s in that Salty Breath of ‘Fresh Air’
Mingxi Yang
Plymouth Marine Laboratory, Prospect Place, The Hoe, Plymouth, UK
Air pollution is responsible for tens of thousands of premature mortality annually in the
UK. Luckily for us, winds from the sea blow most of the local pollutants away and keep
Plymouth clean. Or does it? Here I present 2+ years of continuous trace gas (ozone
and sulphur dioxide) and aerosol observations in the marine atmosphere at the Penlee
Point Atmospheric Observatory near Cawsand, Cornwall. Ozone, one of the principal
air pollutants, is known to damage respiratory tissues and also plant cells. Exhausts
from ships in the English Channel contain sulphur dioxide and aerosols, which strongly
affect human health, precipitation, and climate. I examine changes in the atmospheric
sulphur dioxide levels since 2015 in response to an international regulation on ship
sulphur emission. I also estimate contributions to the aerosol abundance from ship
emissions and sea spray due to wave breaking. I conclude my talk by showing
preliminary lab experiments of ozone reacting with seawater, leading to a loss of
atmospheric ozone and outgassing of volatile organic compounds from the coastal
zones.