Gill Malin

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Verified

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• BSc, PhD
• Emeritus Associate Professor at University of East Anglia

More than 20 years ago Maureen Keller and co-workers published a study that identified dinoflagellates as an important marine phytoplankton group with respect to the production of dimethylsulphoniopropionate (DMSP). Here, we present a synthesis and analysis of all the DMSP and DMSP lyase activity (DLA) measurements currently available for dinoflage...

Climate change and human activities are expected to have a major impact on the structure and functioning of marine ecosystems and the biogeochemical cycles they mediate in the coming years. Here we describe time series measurements of biogenic bromocarbons (CHBr3 and CH2Br2) collected in coastal waters of the western Antarctic Peninsula which is on...

The response to sulfate deficiency of plants and freshwater green algae has been extensively analysed by system biology approaches. By contrast, seawater sulfate concentration is high and very little is known about the sulfur metabolism of marine organisms. Here, we used a combination of metabolite analysis and transcriptomics to analyse the respon...

Current estimates of global halocarbon emissions highlight the tropical coastal environment as an important source of very short-lived (VSL) biogenic halocarbons to the troposphere and stratosphere. This is due to a combination of assumed high primary productivity in tropical coastal waters and the prevalence of deep convective transport potentiall...

The availability of nitrogen varies greatly in the ocean and limits primary productivity over large areas. Diatoms, a group of phytoplankton that are responsible for about 20% of global carbon fixation, respond rapidly to influxes of nitrate and are highly successful in upwelling regions. Although recent diatom genome projects have highlighted clue...

The emission rates of the atmospherically important halogenated trace gases CHBr3, CHBr2Cl and CHBrCl2 were measured from two commercially important tropical red seaweed species Gracilaria manilaensis Yamamoto and Trono, and Kappaphycus alvarezii (Doty) L.M.Liao in a range of environments to investigate the potential impact of seaweed aquaculture o...

Marine research surveys are an integral tool in understanding the marine environment. Recent technological advances have allowed the development of automated or semi-automated methods for the collection of marine data. These devices are often easily implemented on existing surveys and can collect data at finer spatiotemporal resolutions than tradit...

Highlights 1. This policy brief highlights key challenges that must be addressed for the long-term sustainability of the global seaweed industry, ensuring its role in providing nature-based solutions within the sustainable ocean economy agenda and in contributing to the UN Decade of Ocean Science for Sustainable Development (2021-2030). 2. Seaweed...

Cottier-Cook, E.J., Nagabhatla, N., Asri, A., Beveridge, M., Bianchi, P., Bolton, J., Bondad-Reantaso, M.G., Brodie, J., Buschmann, A., Cabarubias, J., Campbell, I., Chopin, T., Critchley, A., De Lombaerde, P., Doumeizel, V., Gachon, C.M.M., Hayashi, L., Hewitt, C.L., Huang, J., Hurtado, A.Q., Kambey, C., Kim, G.H., Le Masson, V., Lim, P.E., Liu, T...

Four tropical seaweeds, Gracilaria manilaensis Yamamoto & Trono, Ulva reticulata Forsskål, Kappaphycus alvarezii (Doty) L.M.Liao and Turbinaria conoides (J.Agardh) Kützing, collected from various habitats throughout Malaysia, were subjected to temperatures of 40, 35, 30, 25 and 20 °C in the laboratory. An exposure range of 21–38 °C is reported for...

The Plankton Imager (PI) is an underway semi-automated, high-speed imaging instrument, which takes images of all passing particles and classifies the mesozooplankton present. We used data (temperature, salinity and mesozooplankton abundance) collected in the Celtic Sea in spring and autumn from 2016 to 2019 to assess the ability of the PI to descri...

This article provides an overview of the approach taken by the Marine Knowledge Exchange Network (M-KEN) and an assessment of its activities in valorizing and generating impact from research. M-KEN was formed in 2014 in response to a call for projects to accelerate impact generated from environmental research in the United Kingdom (UK). M-KEN was u...

Surface ocean biogeochemistry and photochemistry regulate ocean-atmosphere fluxes of trace gases critical for Earth's atmospheric chemistry and climate. The oceanic processes governing these fluxes are often sensitive to the changes in ocean pH (or pCO2) accompanying ocean acidification (OA), with potential for future climate feedbacks. Here, we re...

Volatile halocarbons can deplete the protective stratospheric ozone layer contributing to global climate change and may even affect local climate through aerosol production. These compounds are produced through anthropogenic and biogenic processes. Biogenic halocarbons may be produced as defence compounds, anti-oxidants or by-products of metabolic...

The marine iodine cycle has significant impacts on air quality and atmospheric chemistry. Specifically, the reaction of iodide with ozone in the top few micrometres of the surface ocean is an important sink for tropospheric ozone (a pollutant gas) and the dominant source of reactive iodine to the atmosphere. Sea surface iodide parameterisations are...

Marine algae have been reported as important sources of biogenic volatile halocarbons that are emitted into the atmosphere. These compounds are linked to destruction of the ozone layer, thus contributing to climate change. There may be mutual interactions between the halocarbon emission and the environment. In this study, the effect of irradiance o...

Prymnesium parvum is a toxin-producing microalga that causes harmful algal blooms globally, which often result in large-scale fish kills that have severe ecological and economic implications. Although many toxins have previously been isolated fromP. parvum, ambiguity still surrounds the responsible ichthyotoxins inP. parvumblooms and the biotic and...

Very short-lived halocarbons of marine biogenic origin play an important role in affecting tropospheric and stratospheric chemistry. In recent years, more attention has been paid to tropical regions where the influence of strong convective forces is responsible for rapid uplifting of the volatile organohalogens from the open surface waters into the...

Halocarbons - Biogenic source - Microalgae (Phytoplankton) - Tropical - Climate change

Halocabons - Biogenic source - Microalgae (Phytoplankton) - Tropical - Climate change

A novel marine Alteromonas gracilis siphovirus, phage PB15, was isolated from the surface water of the Yellow Sea in August 2015. It has a head diameter of 58 ± 5 nm head and a contractile tail approximately 105 ± 10 nm in length, and overall, the morphology suggests that PB15 belongs to the family Siphoviridae. PB15 phage is stable at over the tem...

Prymnesium parvum is a toxin-producing haptophyte that causes harmful algal blooms globally, leading to large-scale fish kills that have severe ecological and economic implications. For the model haptophyte, Emiliania huxleyi, it has been shown that large dsDNA viruses play an important role in regulating blooms and therefore biogeochemical cycling...

Five tropical seaweeds, Kappaphycus alvarezii (Doty) Doty ex P.C. Silva, Padina australis Hauck, Sargassum binderi Sonder ex J. Agardh (syn. S. aquifolium (Turner) C. Agardh), Sargassum siliquosum J. Agardh and Turbinaria conoides (J. Agardh) Kützing, were incubated in seawater of pH 8.0, 7.8 (ambient), 7.6, 7.4 and 7.2, to study the effects of cha...

Minimum and maximum changes in pH units (pH 7.2 and pH 8.0) taken at hourly intervals for the first 4 h in the 36 h HEPES buffer stability test ∗ Seaweed species used is S. siliquosum; three replicates used for each treatment method (n = 3).

Halocarbons with their ion fragments, corresponding detection limit and retention timings as detected by the GCMS and the linear regression for their respective calibration curves

Pearson Product-Moment Correlation Coefficient analysis between changes in seawater pH and percentage decrease in Fv∕Fm values of five tropical seaweeds p ≤ 0.01; n = 20; ∗∗ for T. conoides, n = 25; ∗ log values for CH3I emissions from P. australis were used prior to analysis; NS, non-significant; pH value is changed from 8.0, 7.8, 7.6, 7.4 to 7.2.

Percentage decrease (%) in Fv∕Fm ±S.D. for all seaweed species after 4 hour incubation in seawater of varying pH values. Statistical analysis was conducted using one-way ANOVA and Tukey post-hoc analysis Values before ±indicate percentage decrease in maximum quantum yield (Fv∕Fm) that are obtained by calculating the difference between Fv∕Fm values...

Pearson Product-Moment Correlation Coefficient analysis between halocarbon emissions by five seaweed species and percentage decrease in Fv∕Fm values after 4 h incubation in different pH levels p ≤ 0.01 unless otherwise stated; # (p ≤ 0.04); n = 20; ** for T. conoides, n = 25; ∗ log values for CH3I emissions from P. australis were used prior to anal...

Selected halocarbon emission rates (pmol gFW−1 hr−1) ±SD under varying pH for the five seaweed species studied All studies were conducted under similar environmental conditions: (A) irradiance of 85 ±5 µmol photons m−2s−1 photons; (B) Temperature of 30 ±2 °C; (C) average salinity of 30 ±2 PSU; Values before ±indicate average emissions measured in u...

Percentage change (%) of halocarbon emissions by five seaweeds at pH levels relative to ambient pH 7.8 Values before ±indicate average emissions measured in units of percentage (%) in comparison to DW emission rates at ambient pH 7.8; negative values represent emissions that are lower than emissions obtained at ambient pH; Values after ‘±’ indicate...

Long-lived and short-lived halocarbons have long been known for their adverse effects on atmospheric chemistry, especially ozone depletion that may be directly or indirectly influenced by global climate change. Marine organisms including phytoplankton contribute shorter-lived halocarbon compounds to the atmosphere. Oceans cover more than 70% of the...

The Baltic Sea is a unique environment as the largest body of brackish water in the world. Acidification of the surface oceans due to absorption of anthropogenic CO2 emissions is an additional stressor facing the pelagic community of the already challenging Baltic Sea. To investigate its impact on trace gas biogeochemistry, a largescale mesocosm ex...

The Baltic Sea is a unique environment as the largest body of brackish water in the world. Acidification of the surface oceans due to absorption of anthropogenic CO2 emissions is an additional stressor facing the pelagic community of the already challenging Baltic Sea. To investigate its impact on trace gas biogeochemistry, a large-scale mesocosm e...

Picoeukaryotes (<2–3 μm) perform key roles for the functioning of marine ecosystems, but little is known regarding the composition and diversity of picoeukaryotes in aquaculture areas. In this study, the Illumina MiSeq platform was used for sequencing the V4 variable region within the 18S rDNA gene to analyse genetic diversity and relative abundanc...

Environmental context Approximately 25 % of CO2 released to the atmosphere by human activities has been absorbed by the oceans, resulting in ocean acidification. We investigate the acidification effects on marine phytoplankton and subsequent production of the trace gas dimethylsulfide, a major route for sulfur transfer from the oceans to the atmosp...

Exposure of intertidal macroalgae during low tide has been linked to the emission of a variety of atmospherically-important trace gases into the coastal atmosphere. In recent years, several studies have investigated the role of inorganic iodine and organoiodides as antioxidants and their emission during exposure to combat oxidative stress, yet the...

Exposure of intertidal macroalgae during low tide has been linked to the emission of a variety of atmospherically-important trace gases into the coastal atmosphere. In recent years, several studies have investigated the role of inorganic iodine and organoiodides as antioxidants and their emission during exposure to combat oxidative stress, yet the...

Recent years have witnessed significant worldwide growth in research into the production of algal biomass for fuel, food and food supplements, nutrient recovery from waste water and feedstocks for chemical and pharmaceutical industries. While there appear to be considerable future benefits, especially in terms of sustainable low carbon energy biofu...

Despite the importance of dimethylsulphoniopropionate (DMSP) in the global sulphur cycle and climate regulation, the biological pathways underpinning its synthesis in marine phytoplankton remain poorly understood. The intracellular concentration of DMSP increases with increased salinity, increased light intensity and nitrogen starvation in the diat...

Current estimates of global halocarbon emissions highlight the tropical coastal environment as an important source of very short-lived (VSL) biogenic halocarbons to the troposphere and stratosphere, due to a combination of assumed high primary productivity in tropical coastal waters and the prevalence of deep convective transport, potentially capab...

The metabolism of bromine in marine brown algae remains poorly understood. This contrasts with the recent finding that the accumulation of iodide in the brown alga Laminaria serves the provision of an inorganic antioxidant – the first case documented from a living system. The aim of this study was to use an interdisciplinary array of techniques to...

The marine environment is known to be a source of CHBr3 and CH2Br2 and hence ozone-depleting inorganic bromine to the troposphere but, to date, the dominant processes controlling their concentrations in seawater remain poorly understood. Here results are reported from a series of laboratory experiments designed to investigate bromocarbon dynamics i...

Dinoflagellates are recognised as one of the major phytoplankton groups that produce dimethylsulphoniopropionate (DMSP), the precursor of the marine trace gas dimethylsulphide (DMS) which has climate-cooling potential. To improve the prospects for including dinoflagellates in global climate models that include DMSP-related processes, we increased t...

Dinoflagellates are recognised as one of the major phytoplankton groups that produce dimethylsulphoniopropionate (DMSP), the precursor of the marine trace gas dimethylsulphide (DMS) which has climate-cooling potential. To improve the prospects for including dinoflagellates in global climate models that include DMSP-related processes, we increased t...

We measured membrane permeability, hydrolytic enzyme, and caspase-like activities using fluorescent cell stains to document changes caused by nutrient exhaustion in the coccolithophore Emiliania huxleyi and the diatom Thalassiosira pseudonana, during batch-culture nutrient limitation. We related these changes to cell death, pigment alteration, and...

The global surface seawater dimethylsulphide (DMS) database (http://saga.pmel.noaa.gov/dms/) contains >50,000 data points and is the second largest trace gas database after carbon dioxide. However, there has been relatively little quality control on the data that have been collated to date. Furthermore, the recent development of technologies capabl...

Iodomethane (CH3I) production by Prochlorococcus marinus (CCMP 2389) and Synechococcus sp. (CCMP 2370) was investigated using laboratory cultures. In contrast to Synechococcus, where no trace gas production was observed, P. marinus cells produced CH3I. The rate of CH3I production by P. marinus was found to vary depending on the physiological state...

Microzooplankton are ecologically important grazers of phytoplankton and bacteria in aquatic systems. Inhabiting a three-dimensional realm, the ability of a microzooplankter to detect and respond to infochemical cues from its prey will confer a strong selective advantage. The heterotrophic dinoflagellate Oxyrrhis marina has been repeatedly used to...

Ocean dimethylsulfide (DMS) produced by marine biota is the largest natural source of atmospheric sulfur, playing a major role in the formation and evolution of aerosols, and consequently affecting climate. Several dynamic process-based DMS models have been developed over the last decade, and work is progressing integrating them into climate models...

We present an extensive data set of dimethylsulphide (DMS, n = 651) and dimethylsulphoniopropionate (DMSP, n = 590) from the Atlantic Meridional Transect program. These data are used to derive representative depth profiles that illustrate observed natural variations and can be used for DMS and DMSP model‐validation in oligotrophic waters. To furthe...

We investigated dimethylsulphoniopropionate (DMSP) quota (pg DMSP cell(-1)), intracellular DMSP concentration (mM), in vitro and in vivo DMSP-lyase activity (DLA) and dimethylsulphide (DMS) concentration in batch cultures of 10 species of coccolithophore. Species were chosen to span the phylogenetic and size range that exists within the coccolithop...

Dissolved iodine speciation in surface seawater at a coastal Antarctic site has been studied over a period spanning three austral summers. The sampling site is biologically productive, with a summertime algal bloom accompanying strong seasonal variations in physical and chemical parameters. The results suggest a seasonal cycle in which iodide conce...

Using a steady-state diffusion model, we calculated the concentration of the ecologically relevant algal metabolite dimethylsulphoniopropionate (DMSP) in the phycosphere. Incorporating diffusive losses, the concentration was predicted to be 10(6)-fold lower than previously suggested.

The oceans play a key role in climate regulation especially in part buffering (neutralising) the effects of increasing levels of greenhouse gases in the atmosphere and rising global temperatures. This chapter examines how the regulatory processes performed by the oceans alter as a response to climate change and assesses the extent to which positive...

We investigated the relationship between microplankton composition and dimethylsulphide (DMS) concentration in the Mauritanian upwelling in July/August 2006. As well as DMS and DMSP-lyase activity (DLA), we made some accompanying measurements of the precursor of DMS, DMSP (dimethylsulphoniopropionate) in the particulate and dissolved fraction, and...

Measurements of the efficiency of photosystem (PS) II have become widespread in bio- logical oceanography, and various forms are used to assess the ‘health’ of marine phytoplankton and to help estimate primary productivity. Absolute values of PS II efficiency depend to some extent on the measuring system, but changes in PS II efficiency are most co...

A number of field and laboratory studies on the impact of marine macroalgae on dissolved inorganic iodine speciation are presented. Within tidally isolated rock pools, the brown macroalga Fucus serratus was found to both release stored iodide and to facilitate the reduction of iodate to iodide. In contrast, no discernible changes in iodine speciati...

The oceans play a key role in climate regulation especially in part buffering (neutralising) the effects of increasing levels of greenhouse gases in the atmosphere and rising global temperatures. This chapter examines how the regulatory processes performed by the oceans alter as a response to climate change and assesses the extent to which positive...

Symploca PCC 8002 Kützing is a filamentous cyanobacterium that lacks the specialized cells, known as heterocysts, that protect nitrogenase from O2 in most aerobic N2-fixing cyanobacteria. Nevertheless, Symploca is able to carry out N2 fixation in the light under aerobic conditions. When cultures were grown under light/dark cycles, nitrogenase activ...

We present the first reported measurements of volatile iodocarbon production by biogenic marine aggregates. Iodomethane (CH₃I), iodoethane (C₂H₅I), 2- iodopropane (CH₃CHICH₃), and 1-iodopropane (CH₃CH₂CH₂I) concentrations were determined in incubations of aggregates formed by concentrating the >53 µm fraction of the plankton during a field campaign...

We present the first reported measurements of volatile iodocarbon production by biogenic marine aggregates. Iodomethane (CH3I), iodoethane (C2H5I), 2- iodopropane (CH3CHICH3), and 1-iodopropane (CH3CH2CH2I) concentrations were determined in incubations of aggregates formed by concentrating the .53 mm fraction of the plankton during a field campaign...

The contemporary atmosphere was created as a result of biological activity some two billion years ago. To this day, its natural composition is supported and modified, mostly through biological processes of trace gas production and destruction, while also involving physical and chemical degradation processes. The biosphere has a major influence on p...

We determined growth rates of six coccolithophorid strains (five species) as a function of temperature. We grew four strains (three species: Emiliania huxleyi, Gephyrocapsa oceanica, and two strains of Calcidiscus leptoporus) at six temperatures between 6°C and 25°C, Coccolithus braarudii at four temperatures, and Syracosphaera pulchra at two tempe...

Most oceanic dimethyl sulphide (DMS) is produced through the enzymatic cleavage of dimethylsulphoniopropionate (DMSP), a process governed by the activity of DMSP-lyases in algae and bacteria. Laboratory and field experiments with the DMS-producing coccolithophorid Emiliania huxleyi have advanced our understanding of algal DMSP lyases. However, desp...

In vitro DMSP-lyase activity (DLA) measurements were made during an Atlantic Meridional Transect (AMT) cruise in May 2004, which travelled through the southern and northern oligotrophic gyres. Along the transect, twice-daily measurements were taken from the surface (0.5 ? 8.0 m) and the chlorophyll maximum (chl max; 47 ? 150 m). Surface samples sho...

In vitro DMSP-lyase activity (DLA) me-asurements were made during an Atlantic Meridional Transect (AMT) cruise in May 2004, which travelled through the southern and northern oligotrophic gyres. Along the transect, twice-daily measurements were taken from the surface (0.5 – 8.0 m) and the chloro-phyll maximum (chl max; 47 – 150 m). Surface sam-ples...

Seawater concentrations of the climate-cooling, volatile sulphur compound dimethylsulphide (DMS) are the result of numerous production and consumption processes within the marine ecosystem. Due to this complex nature, it is difficult to predict temporal and geographical distribution patterns of DMS concentrations and the inclusion of DMS into globa...

Dimethylsulfoniopropionate (DMSP) cleavage was investigated during culture studies of grazing by the microzooplankter Oxyrrhis marina and viral lysis by Emiliania huxleyi virus 86 (EhV-86) on two axenic strains of E. huxleyi. The cleavage products of DMSP, dimethyl sulfide (DMS) and acrylic acid (AA), accumulated during viral infection of both stra...

Seawater concentrations of the climate-cooling, volatile sulphur compound dimethylsulphide (DMS) are the result of numerous production and consumption processes within the marine ecosystem. Due to this complex nature, it is difficult to predict temporal and geographical distribution patterns of DMS concentrations and the inclusion of DMS into globa...

The presence of a surface iodide maximum in seawater is commonly attributed to biological activity, however laboratory studies on the influence of phytoplankton on inorganic iodine speciation have yielded somewhat contradictory results. Here, we report changes in the speciation of inorganic dissolved iodine in nutrient-enriched seawater during the...

Dimethyl sulfide (DMS) is a key compound in global sulfur and carbon cycles. DMS oxidation products cause cloud nucleation and may affect weather and climate. DMS is generated largely by bacterial catabolism of dimethylsulfoniopropionate (DMSP), a secondary metabolite made by marine algae. We demonstrate that the bacterial gene dddD is required for...

The aims of the Atlantic Meridional Transect (AMT) programme [www.amt-uk.org] are to quantify the nature and causes of ecological and biogeochemical variability in the planktonic ecosystems of the Atlantic Ocean, and to assess the effects of this variability on biological carbon cycling and air–sea exchange of radiatively active gases and aerosols....

We investigated the influence of high light stress on iodocarbon release by three species of marine phytoplankton from different algal classes: the prymnesiophyte Emiliania huxleyi, the prasinophyte Tetraselmis sp., and the diatom Thalassiosira pseudonana. Despite a pronounced decrease in the fluorescence-based maximum quantum yield for photosystem...

The effect of viral infection of Emiliania huxleyi (Lohman) Hay and Mohler on the concentration of intracellular reactive oxygen species (ROS), hydrogen peroxide (H2O2) excretion and cell photosynthetic capacity (CPC) was examined. During the crash of an E. huxleyi culture induced by viruses intracellular ROS concentrations were generally elevated...

We examined the ability of dimethylsulfoniopropionate (DMSP), its cleavage products dimethyl sulfide (DMS) and acrylic acid (AA), and the oxidized form of DMS dimethylsulfoxide (DMSO), to inhibit infection of Emiliania huxleyi virus 86 (EhV-86). Infectivity was assessed by plaque assay of viral stock that had been exposed to these compounds. The in...

Measurements of the climate-cooling trace gas dimethylsulphide (DMS) and other ancillary data, including pigments, nutrient concentrations and the depth of the mixed layer, were made over a wide latitude range during the UK Atlantic Meridional Transect (AMT) programme. The data were used to test algorithms from the recent literature for their effec...

Ethene (ethylene; H2C = CH2) is one of a range of non-methane hydrocarbons (NMHC) that affect atmospheric chemistry and global climate. Ethene acts as a hormone in higher plants and its role in plant biochemistry, physiology and ecology has been the subject of extensive research. Ethene is also found in seawater, but despite evidence that marine mi...

Emiliania huxleyi (Lohm.) Hay and Mohler is a ubiquitous unicellular marine alga surrounded by an elaborate covering of calcite platelets called coccoliths. It is an important primary producer involved in oceanic biogeochemistry and climate regulation. Currently, E. huxleyi is separated into five morphotypes based on morphometric, physiological, bi...

Dimethylsulphoxide ((CH3)2SO; DMSO) occurs naturally in marine and freshwater environments, rainwater, and the atmosphere. It is thought to be an environmentally significant compound due to the potential role it plays in the biogeochemical cycle of the climatically active trace gas, dimethylsulphide (DMS). Generally it has been assumed mat the phot...

It is hard to find a research paper or book on coccolithophores that does not include a few sentences on the role of this fascinating and enigmatic marine phyto- plankton group in the production of dimethyl sulfide ((CH3)2S; DMS). Our aim here is to provide some general background information on DMS for non- specialists, but also to highlight curre...

Non-methane hydrocarbons (NMHCs) are produced naturally in the ocean and by terrestrial vegetation. Owing to its high reactivity and flux, isoprene (2-methyl-1,3-butadiene) is important in controlling the balance of atmospheric oxidants, and altering air quality on both local and global scales. Here we show, for the first time, that macroalgae (sea...