18 September, 2024 by James Smith, Kelly Hogan
During Quaternary glaciations, ice sheets expanded from continental interiors across continental shelves and delivered large volumes of sediment, transported by meltwater, and icebergs to the marine environment. Glaciomarine sediments preserve…18 September, 2024 by Claire Allen, Dieter Tetzner
Here, we summarize the diatom research topics and applications that have the broadest relevance and importance for Antarctic studies. From the Southern Ocean we focus on biogeography, sea surface temperature…18 September, 2024 by Lloyd Peck, Nicholas Barrett
Climate change is causing increased coastal freshening in Antarctica, leading to reduced salinity. For Antarctica’s endemic echinoderms, adapted to the stable polar environment, the impact of rapid reductions in coastal…Read more on The impact of acute low salinity stress on Antarctic echinoderms
17 September, 2024 by Dani Jones, Paul Holland
The Amundsen Sea in West Antarctica features rapidly thinning ice shelves, large polynyas, and sizable spring phytoplankton blooms. Although considerable effort has gone into characterizing heat fluxes between the Amundsen…15 September, 2024 by Dani Jones
We construct an upper ocean (0-1000m) North Atlantic heat budget (26°-67°N) for the period 1950-2020 using multiple observational datasets and an eddy-permitting global ocean model. On multidecadal timescales ocean heat…Read more on Ocean heat convergence and North Atlantic multidecadal heat content variability
15 September, 2024 by Mervyn Freeman
Substorms are a rapid release of energy that is redistributed throughout the magnetosphere‐ionosphere system, resulting in many observable signals, such as enhancements in the aurora, energetic particle injections, and ground…Read more on On the Association of Substorm Identification Methods
14 September, 2024 by Bryony Freer, Oliver Marsh
Antarctica has an active subglacial hydrological system, with interconnected subglacial lakes fed by subglacial meltwater. Subglacial hydrology can influence basal sliding, inject freshwater into the sub-ice-shelf cavity, and impact sediment…13 September, 2024 by Yohei Takano
This study examines the linkages between the upper-ocean (0–200 m) oxygen (O2) content and stratification in the North Pacific Ocean using four Earth system models (ESMs), an ocean hindcast simulation, and…11 September, 2024 by Kate Hendry
Accelerated mass loss from the Greenland Ice Sheet leads to retreating glaciers and enhanced freshwater runoff to adjacent coastal regions, potentially providing additional essential nutrients, such as silicon, to downstream…11 September, 2024 by Peter Convey
Microalgae are gaining considerable attention in the field of cosmeceuticals due to their unique profile. In particular, the diverse range of valuable bioactive compounds isolated from microalgae are known to…11 September, 2024 by Michael Meredith
High-latitude pelagic marine ecosystems are vulnerable to climate change because of the intertwining of sea/continental ice dynamics, physics, biogeochemistry, and food-web structure. Data from the West Antarctic Peninsula allow us…Read more on Antarctic pelagic ecosystems on a warming planet
11 September, 2024 by Jakob Thyrring, Lloyd Peck
The availability of online biodiversity data has increased in recent decades, aiding our understanding of diversity patterns and species richness–environment relationships across temporal and spatial scales. However, even the most…10 September, 2024
The gut microbiota-immune-brain axis is a feedback network which influences diverse physiological processes and plays a pivotal role in overall health and wellbeing. Although research in humans and laboratory mice…9 September, 2024 by Richard Phillips
Estimates of movement costs are essential for understanding energetic and life-history trade-offs. Although overall dynamic body acceleration (ODBA) derived from accelerometer data is widely used as a proxy for energy…Read more on Dynamic soaring decouples dynamic body acceleration and energetics in albatrosses
7 September, 2024 by Sophie Fielding
Classification of zooplankton to species with broadband echosounder data could increase the taxonomic resolution of acoustic surveys and reduce the dependence on net and trawl samples for ‘ground truthing’. Supervised…5 September, 2024 by Andrew Clelland, Gareth Marshall
Boreal and Arctic regions have warmed up to four times quicker than the rest of the planet since the 1970s. As a result, boreal and tundra ecosystems are experiencing more…5 September, 2024 by Carl Robinson, Keith Nicholls, Tom Jordan
As a part of the project "Melting at Thwaites grounding zone and its control on sea level" (MELT), we developed a compact 750-MHz ice-penetrating radar for phase-sensitive measurements to infer…Read more on An UWB UHF Ice-Penetreating Radar for the Thwaites Melt Project
4 September, 2024 by Katrin Linse
Confined by the Mid-Atlantic Ridge and the European continental shelf, the deep-sea acorn barnacle Bathylasma hirsutum (Hoek, 1883) lives in the northeast Atlantic deep sea where it has been frequently…4 September, 2024 by Ashley Bennison
Density-dependent competition for food influences the foraging behaviour and demography of colonial animals, but how this influence varies across a species’ latitudinal range is poorly understood. Here we used satellite…3 September, 2024 by Ashley Bennison, Elaine Fitzcharles, Freya Blockley, Marcia Blyth, Rosamund Hall
Until recent events, the Antarctic was the only major geographical region in which high pathogenicity avian influenza virus (HPAIV) had never previously been detected. Here we report on the detection…3 September, 2024 by Huw Griffiths, Rowan Whittle
The benthic community around Antarctica is diverse and highly endemic. These cold-adapted species are under threat from local and global drivers, including warming, acidification and changes to the cryosphere. In…1 September, 2024 by Peter Convey
Marine birds and pinnipeds which come to land to breed, rest and moult are widely known to fertilize adjacent terrestrial ecosystems, with cascading effects on vegetation and other trophic levels.…Read more on The impact of marine vertebrates on polar terrestrial invertebrate communities
1 September, 2024 by Peter Convey
While long-range transport is believed to be the primary source of mercury (Hg) in Antarctica, it is known that seabirds transport organic matter, nutrients, and contaminants from the sea to…Read more on Ornithogenic mercury input to soils of Admiralty Bay, King George Island, Antarctica
1 September, 2024 by Andrew Clarke, Lloyd Peck, Melody Clark
The affect of temperature on tissue protein synthesis rates has been reported in temperate and tropical, but not Antarctic fishes. Previous studies have generally demonstrated low growth rates in Antarctic…1 September, 2024 by Xu Zhang
Terrestrial vegetation is a crucial component of the Earth system, and its changes not only represent one of the most distinct aspects of climate change but also exert significant feedback…Read more on Progress of vegetation modelling and future research prospects
1 September, 2024 by Steve Colwell
The Year of Polar Prediction in the Southern Hemisphere (YOPP-SH) held seven Targeted Observing Periods (TOPs) during the 2022 austral winter to enhance atmospheric predictability over the Southern Ocean and…1 September, 2024 by Andrew Kavanagh, Ingrid Cnossen
Increasing carbon dioxide concentrations in the mesosphere and lower thermosphere are increasing radiative cooling in the upper atmosphere, leading to thermospheric contraction and decreased neutral mass densities at fixed altitudes.…Read more on Future Climate Change in the Thermosphere Under Varying Solar Activity Conditions
30 August, 2024 by Yohei Takano
Since their advent over 2 decades ago, autonomous Argo floats have revolutionized the field of oceanography, and, more recently, the addition of biogeochemical and biological sensors to these floats has…28 August, 2024 by Andrew Kavanagh
Cold plasma of ionospheric origin has recently been found to be a much larger contributor to the magnetosphere of Earth than expected. Numerous competing mechanisms have been postulated to drive…Read more on Earth’s ambipolar electrostatic field and its role in ion escape to space
26 August, 2024 by Andrew Orr, Gareth Marshall, Nadine Johnston, Ryan Williams
While climate models broadly agree on the changes expected to occur over the Arctic with global warming on a pan-Arctic scale (i.e. polar amplification, sea ice loss, and increased precipitation),…26 August, 2024 by Peter Convey
The use of yeasts has been explored as an efficient alternative to fungicide application in the treatment and prevention of post-harvest fruit deterioration. Here, we evaluated the biocontrol abilities of…23 August, 2024 by Kate Hendry
The polar regions are experiencing the most rapid climate change observed on Earth. Marine ecosystems are already responding to – and amplifying – environmental change, with important implications for carbon…Read more on SiCLING Ny-Ålesund Fieldwork Report. 15th – 29th July 2024
22 August, 2024 by Neil Brough
Water insoluble organic material extracted from atmospheric aerosol samples collected in urban (Royal Holloway, University of London, UK) and remote (Halley, Antarctica) locations were shown to form stable thin films…20 August, 2024 by Dieter Tetzner
The pattern of atmospheric and climate changes recorded by coastal Antarctic ice core sites, and the processes they illustrate, highlight the importance of multiproxy studies on ice cores drilled from…19 August, 2024 by Claus-Dieter Hillenbrand
Knowledge of the behaviour of marine-based ice sheets during times of climatic warming, such as the last deglaciation, provides important information to understand how ice sheets respond to external forcing.…19 August, 2024 by Chester Sands, Peter Convey
Accurate knowledge of geographic ranges of species is essential for effective conservation management. Species with large distributions and good connectivity are presumed to be resilient to adverse localised/regional conditions, whereas…19 August, 2024 by Andrew Wood, Richard Phillips, Victoria Warwick-Evans
The Antarctic seasonal sea-ice zone (SIZ) is one of the most extensive and dynamic habitats on Earth. In summer, increased insolation and ice melt cause primary production to peak, sustaining…15 August, 2024
The Southern Ocean is a unique and extreme environment that is changing fast due to climate change, with shifts recorded from the surface to deep-sea ecosystems. By evolving in such…15 August, 2024 by Ronan Agnew
Seismic observations of glacier beds are key to understanding processes of basal slip and incorporating these processes into ice sheet models, which in turn inform predictions of global sea level…15 August, 2024 by Philip Trathan
Biodiversity is critical for maintaining ecosystem function but is threatened by increasing anthropogenic pressures. In the Southern Ocean, a highly biologically productive region containing many endemic species, proactive management is…15 August, 2024 by Paul Holland
A crucial factor influencing the mass balance of the West Antarctic Ice Sheet is the Amundsen Sea Low (ASL), a climatological low-pressure region situated off the West Antarctic coast. However,…15 August, 2024 by Gareth Chisham
The aurora and associated high energy particles and currents pose a space weather hazard to communication networks and ground-based infrastructure. Forecasting the location of the auroral oval forms an integral…15 August, 2024 by Claus-Dieter Hillenbrand
With the onset of anthropogenic climate change, it is vital that we understand climate sensitivity and rates of change during periods of warming in the Earth's past to properly inform…14 August, 2024
Polar offshore environments are considered the last pristine soundscapes, but accelerating climate change and increasing human activity threaten their integrity. In order to assess the acoustic state of polar oceans,…7 August, 2024 by Clara Manno, Florence Atherden
Southern Ocean zooplankton provide globally significant ecosystem services through their role in carbon sequestration, nutrient cycling and food webs. However, the remote and extreme nature of the Southern Ocean creates…Read more on Sediment trap illustrates taxon-specific seasonal signals in Southern Ocean zooplankton
7 August, 2024 by Martin Rogers
Mapping sea ice in the Arctic is essential for maritime navigation, and growing vessel traffic highlights the necessity of the timeliness and accuracy of sea ice charts. In addition, with…6 August, 2024 by Christopher Auckland, Povl Abrahamsen, Michael Meredith
The Antarctic Bottom Water (AABW) exported from the Weddell Sea has experienced warming and contraction in the past 30 yrs. Superposed on this decadal trend is substantial annual and interannual…6 August, 2024 by Joanne Johnson, Peter Convey, Peter Fretwell
Terrestrial vegetation communities across Antarctica are characteristically sparse, presenting a challenge for mapping their occurrence using remote sensing at the continent scale. At present there is no continent-wide baseline record…Read more on A satellite-derived baseline of photosynthetic life across Antarctica
5 August, 2024
Inbreeding, the mating of individuals that are related through common ancestry, is of central importance in evolutionary and conservation biology due to its impacts on individual fitness and population dynamics.…5 August, 2024 by Diana Vladimirova, Dieter Tetzner, Ivo Strawson, Jack Humby, Liz Thomas, Thomas Bauska
Biomass burning plays an important role in climate-forcing and atmospheric chemistry. The drivers of fire activity over the past two centuries, however, are hotly debated and fueled by poor constraints…2 August, 2024 by Xu Zhang
Despite extensive investigation, the nature and causes of the Mid-Pleistocene Transition remain enigmatic. In this work, we assess its linkage to asynchronous development of bipolar ice sheets by synthesizing Pleistocene…Read more on Mid-Pleistocene climate transition triggered by Antarctic Ice Sheet growth
2 August, 2024 by Hugh Venables
Scarcity of iron and manganese limits the efficiency of the biological carbon pump over large areas of the Southern Ocean. The importance of hydrothermal vents as a source of these…Read more on Pathways and timescales of Southern Ocean hydrothermal iron and manganese transport
1 August, 2024 by Peter Fretwell
Predictions of the future emperor penguins population, linked to anthropogenic climate change, are stark. Current models suggest that if CO2 emissions continue to rise at present rates, almost all colonies…Read more on Four unreported emperor penguin colonies discovered by satellite
1 August, 2024 by Peter Convey
We studied the culturable fungal community recovered from deep marine sediments in the maritime Antarctic, and assessed their capabilities to produce exoenzymes, emulsifiers and metabolites with phytotoxic activity. Sixty-eight Ascomycota…1 August, 2024 by Amanda Burson, Cecilia Liszka, Clara Manno, Povl Abrahamsen, Geraint Tarling, Kate Hendry, Natasha Lucas, Sally Thorpe
Large icebergs (>20 km long) are responsible for most of the freshwater discharged into the Southern Ocean. We report on in situ and satellite observations made during the break-up phase around…1 August, 2024 by Markus Frey
Novel observations of aerosol and clouds by means of ground-based remote sensing have been performed in Antarctica over the Ekström ice shelf on the coast of Dronning Maud Land at…1 August, 2024 by Richard Phillips
Seabirds are amongst the most threatened taxa in the world, often due to incidental mortality (bycatch) in fisheries. Hundreds of thousands are thought to be killed worldwide in gillnets and…Read more on Incidental mortality of seabirds in trawl fisheries: A global review
31 July, 2024 by Hugo Rodrigues Guimaro
The participation of a diverse –in terms of geography, discipline and gender– group of Early Career Researchers (ECRs) in the peer review process can help alleviate the workload of senior…31 July, 2024 by Kelly Hogan, Peter Davis, Robert Larter
Knowledge gaps about how the ocean melts Antarctica’s ice shelves, borne from a lack of observations, lead to large uncertainties in sea level predictions. Using high-resolution maps of the underside…28 July, 2024 by Anna Jones, Evelyn Workman, Katrin Linse
Sea-air methane flux was measured directly by the eddy-covariance method across approximately 60,000 km of Arctic and Antarctic cruises during a number of summers. The Arctic Ocean (north of 60°N,…24 July, 2024 by Andrew Meijers, Jonathan Rosser
The Southern Ocean provides dominant contributions to global ocean heat and carbon uptake, which is widely interpreted as resulting from its unique upwelling and circulation. Here we show a large…Read more on Asymmetries in the Southern Ocean contribution to global heat and carbon uptake
22 July, 2024 by Andrew Kavanagh, Gareth Chisham, Mervyn Freeman
A significant increase in the number of anthropogenic objects in Earth orbit has necessitated the development of satellite conjunction assessment and collision avoidance capabilities for new spacecraft. Neutral mass density…Read more on Influences of Space Weather Forecasting Uncertainty on Satellite Conjunction Assessment
19 July, 2024 by Claus-Dieter Hillenbrand, James Smith, Robert Larter
One of Earth’s most fundamental climate shifts – the greenhouse-icehouse transition 34 Ma ago – initiated Antarctic ice-sheet build-up, influencing global climate until today. However, the extent of the ice…Read more on Ice sheet–free West Antarctica during peak early Oligocene glaciation
19 July, 2024 by Michael Meredith
Many glaciers on the Antarctic Peninsula have retreated and accelerated in recent decades. Here we show that there has been a widespread, quasi-synchronous, and sustained increase in grounding line discharge…Read more on Widespread increase in discharge from West Antarctic Peninsula glaciers since 2018
17 July, 2024 by Chester Sands, Peter Convey
The Southern Ocean benthos is remarkably rich and diverse, and managed under a complexity of treaties and conventions, further complicated by geopolitical boundaries. Traditionally, conservation management is largely informed by…17 July, 2024 by Richard Horne
Updated summaries of the August 1972 and March 1989 space weather events have been constructed. The features of these two events are compared to the Carrington 1859 event and a…15 July, 2024 by James Smith
The Northeast Greenland Ice Stream (NEGIS) is the main artery for ice discharge from the northeast sector of the Greenland Ice Sheet (GrIS) to the North Atlantic. Understanding the past,…Read more on The deglacial history of 79N glacier and the Northeast Greenland Ice Stream
15 July, 2024 by Gareth Chisham, Mervyn Freeman
The ability to understand and model ionospheric plasma flow on all spatial scales has important implications for operational space weather models. This study exploits a recently developed method to statistically…14 July, 2024 by Dominic Hodgson
Here, we explore the profound impact of the Tasmanian Aboriginal (Palawa) people on Tasmanian landscapes by examining a 22,000-year record of landscape change from Lake Selina in western Tasmania, Australia.…Read more on Reconciling 22,000 years of landscape openness in a renowned wilderness
14 July, 2024 by Michael Meredith
The mixing of water in the ocean is a key influence on our climate and ecosystems, but its importance is often under-recognized. Mixing in the seas around Antarctica—a key process…12 July, 2024
Background - Assessing the historical dynamics of key food web components is crucial to understand how climate change impacts the structure of Arctic marine ecosystems. Most retrospective stable isotopic studies…Read more on Insights on long-term ecosystem changes from stable isotopes in historical squid beaks
11 July, 2024 by Chester Sands, Felipe Simoes, Peter Convey
The terrestrial fauna of Antarctica consists of a limited number of species, notably insects, small crustaceans and other micro-invertebrates. Over long periods of evolutionary isolation, these organisms have developed varying…9 July, 2024 by Aaron Hendry, Alexander Lozinski, Mark Clilverd
High energy resolution DEMETER satellite observations from the Instrument for the Detection of Particle (IDP) are analyzed during an electromagnetic ion cyclotron (EMIC)-induced electron precipitation event. Analysis of an Interval…5 July, 2024 by Claus-Dieter Hillenbrand
Detrital smectite is a ubiquitous clay mineral in marine sediments and has a variable total Fe, Al, and Mg composition depending on the source, i.e., bedrock or unconsolidated sedimentary strata,…4 July, 2024 by Kaitlin Naughten
The Amundsen Sea region in Antarctica is a critical area for understanding future sea level rise due to its rapidly changing ice dynamics and significant contributions to global ice mass…4 July, 2024 by Alison Cleary, Frances Perry, Geraint Tarling
Antarctic krill Euphausia superba are key components of Southern Ocean ecosystems and biogeochemical cycles, as well as the target of a growing commercial fishery. Understanding the drivers of variability in…3 July, 2024 by Gareth Chisham
The ground-based, high-frequency radars of the Super Dual Auroral Radar Network (SuperDARN) observe backscatter from ionospheric field-aligned plasma irregularities and features on the Earth's surface out to ranges of several…Read more on Multi‐Frequency SuperDARN Interferometer Calibration [Method]
2 July, 2024 by Peter Convey
We assessed soil fungal and fungal-like diversity using metabarcoding in ornithogenically influenced soils around nests of the bird species Phalacrocorax atriceps, Macronectes giganteus, Pygoscelis antarcticus, and Pygoscelis adelie on the…2 July, 2024 by Huw Griffiths, Rowan Whittle, Tasnuva Khan
Predator-prey interactions in marine ecosystems control population sizes, maintain species richness, and provide intermediate disturbance. Such ecosystem structuring interactions may be rare in Antarctic epibenthic communities, which are unique among…1 July, 2024 by Jasmine Lee
Conserving landscapes used by multiple stakeholder groups requires understanding of what each stakeholder values. Here we employed a semi-structured, participatory approach to identify features of value in the terrestrial Antarctic…Read more on Conservation features of the terrestrial Antarctic Peninsula
1 July, 2024 by Hua Lu, John King, Thomas Caton Harrison, Thomas Bracegirdle
Antarctic coastal surface winds affect ice-sheet stability, sea ice, and local ecosystems. The strongest coastal winds are especially important due to the nonlinear relationship between wind speed and wind stress.…1 July, 2024 by Alexander Brearley
Mixing in the upper ocean is important for biological production and the transfer of heat and carbon between the atmosphere and deep ocean, properties commonly targeted by observational campaigns using…Read more on Evaluating Existing Ocean Glider Sampling Strategies for Submesoscale Dynamics
1 July, 2024 by Alastair Wilson, Claire Waluda, Kate Owen, Martin Collins, Meghan Goggins, Philip Hollyman, Philip Trathan
The sub-Antarctic island of South Georgia is surrounded by highly productive waters, supporting dense aggregations of Antarctic krill (Euphausia superba), a vital food source for globally important seabird and marine…1 July, 2024 by Richard Phillips
Procellariiform seabirds can accumulate high levels of plastic in their gastrointestinal tracts, which can cause physical damage and potentially provides a contamination route for trace elements. We examined plastic ingestion…1 July, 2024 by Huw Griffiths
No other group of animals typifies the uniqueness of Antarctic life more than Pycnogonida (sea spiders), with 20% of all known species found in the Southern Ocean, and 64% of…Read more on Antarctica is less isolated with increasing depth – evidence from pycnogonids
1 July, 2024 by Lloyd Peck
Climate change is known to affect the distribution and composition of species, but concomitant alterations to functionally important aspects of behaviour and species-environment relations are poorly constrained. Here, we examine…1 July, 2024 by Josephine Anselin, Paul Holland
Efforts to parameterize ice shelf basal melting within climate models are limited by an incomplete understanding of the influence of ice base slope on the turbulent ice shelf–ocean boundary current…Read more on Ice Base Slope Effects on the Turbulent Ice Shelf–Ocean Boundary Current
1 July, 2024 by Andrew Meijers
Workshop on Antarctic Ice Shelf Processes in Models and Earth Observation.29 June, 2024 by Irene Malmierca Vallet, John Slattery, Louise Sime
Greenland ice core records feature Dansgaard–Oeschger (D-O) events, which are abrupt warming episodes followed by gradual cooling during ice age climate. The three climate models used in this study (CCSM4,…29 June, 2024 by Cameron Fox-Clarke, Camille Toscani, Claire Stainfield, Jaume Forcada
Immune defenses are crucial for survival but costly to develop and maintain. Increased immune investment is therefore hypothesized to trade-off with other life-history traits. Here, we examined innate and adaptive…29 June, 2024 by Caroline Holmes, John Turner, Thomas Caton Harrison, Tony Phillips, Tylei Reeves-Francois
We investigate an unusual extensive ice-free feature (EIF) within the pack ice that developed in the central Weddell Sea in December 1980 on the edge of the multi-year sea ice…28 June, 2024 by Kate Hendry
In the Arctic and subarctic oceans, the relatively low supply of silicon (compared to other nutrients) can make it limiting for the growth of diatoms, a fundamental building block of…Read more on Detrital input sustains diatom production off a glaciated Arctic coast
28 June, 2024 by Nigel Meredith, Richard Horne, Sarah Glauert, Thomas Daggitt
The plasma density is one of the most fundamental quantities of any plasma yet measuring it in space is exceptionally difficult when the density is low. Measurements from particle detectors…28 June, 2024 by Alexander Whittle, Dominic Hodgson
Radiocarbon dating of basal peats has been a key factor in determining minimum ages for deglaciation on sub-Antarctic islands. On Marion Island, peat bogs dominate the landscape below 300 m a.s.l.,…25 June, 2024 by Alexander Bradley
Marine ice sheets are highly sensitive to submarine melting in their grounding zones, where they transition between grounded and floating ice. Recently published studies of the complex hydrography of grounding…Read more on Tipping point in ice-sheet grounding-zone melting due to ocean water intrusion
24 June, 2024 by Ben Robinson, David Seaton, Kevin Hughes, Simon Morley
Shallow water Antarctic marine macroepifaunal assemblages live in one of the most naturally disturbed marine environments due to the impact of icebergs scouring the seafloor. They are, however, amongst the…Read more on Measuring the impact of wharf construction on the Antarctic Benthos
24 June, 2024 by David Barnes
The seabed of the Antarctic continental shelf hosts most of Antarctica's known species, including taxa considered indicative of vulnerable marine ecosystems (VMEs). Nonetheless, the potential impact of climatic and environmental…Read more on Variability in Zoobenthic Blue Carbon storage across a Southern Polar Gradient
22 June, 2024 by Peter Convey
This study characterized cultivable fungi present in sediments obtained from Boeckella Lake, Hope Bay, in the north-east of the Antarctic Peninsula, and evaluated their production of enzymes and biosurfactants of…