About
78
Publications
15,000
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
1,472
Citations
Introduction
Skills and Expertise
Publications
Publications (78)
Microplastic pollution in remote inland Antarctica is largely unknown. This study explored the plastic footprint of snow from remote Antarctic camps; Union Glacier, Schanz Glacier and the South Pole. Refined automated FTIR techniques enabled interrogation of <25 µm microplastics and fibres in Antarctic snow for the first time. Microplastics were pe...
The biological carbon pump is responsible for much of the decadal variability in the ocean carbon dioxide (CO2) sink, driving the transfer of carbon from the atmosphere to the deep ocean. A mechanistic understanding of the ecological drivers of particulate organic carbon (POC) flux is key both to the assessment of the magnitude of the ocean CO2 sin...
Estimated plastic debris floating at the ocean surface varies depending on modelling approaches, with some suggesting unaccounted sinks for marine plastic debris due to mismatches between plastic predicted to enter the ocean and that accounted for at the surface. A major knowledge gap relates to the vertical sinking of oceanic plastic. We used an a...
Planktonic Foraminifera are unique paleo-environmental indicators through their excellent fossil record in ocean sediments. Their distribution and diversity are affected by different environmental factors including anthropogenically forced ocean and climate change. Until now, historical changes in their distribution have not been fully assessed at...
Antarctic krill (Euphausia superba) plays a central role in the Antarctic marine food web and biogeochemical cycles and has been identified as a species that is potentially vulnerable to plastic pollution. While plastic pollution has been acknowledged as a potential threat to Southern Ocean marine ecosystems, the effect of nanoplastics (<1000 nm) i...
Pteropods are a key part of biogeochemical cycling and epipelagic food webs in the Southern Ocean. However, shelled pteropods are vulnerable to climate change, due to their aragonite shells being particularly sensitive to ocean acidification. Currently our understanding of pteropod responses to environmental change is hindered by uncertainties surr...
Microplastics (MP) have been reported in Southern Ocean (SO), where they are likely to encounter Antarctic zooplankton and enter pelagic food webs. Here we assess the presence of MP within Antarctic krill (Euphausia superba) and salps (Salpa thompsoni) and quantify their abundance and type by micro-Fourier transform infrared microscopy. MP were fou...
Planktonic calcifying organisms play a key role in regulating ocean carbonate chemistry and atmospheric CO2. Surprisingly, references to the absolute and relative contribution of these organisms to calcium carbonate production are lacking. Here we report quantification of pelagic calcium carbonate production in the North Pacific, providing new insi...
The biological carbon pump is responsible for much of the decadal variability in the ocean carbon dioxide (CO2) sink, driving the transfer of carbon from the atmosphere to the deep ocean. A mechanistic understanding of the ecological drivers of particulate organic carbon (POC) flux is key to both the assessment of the magnitude of the ocean CO2 sin...
The reproductive strategy of planktonic foraminifera, key pelagic calcifiers, has long remained elusive, hampering efforts to understand and model their population dynamics. This is particularly critical in polar oceans where their success relies on rapid population growth after the polar night. Here, we provide field and laboratory observations co...
Thecosome pteropods are a dominant group of calcifying pelagic molluscs and an important component of the food web. In this study, we characterise spring pteropod distribution throughout the Mediterranean Sea, an understudied region for this common group of marine calcifying organisms. This semi-enclosed sea is rapidly changing under climatic and a...
Estimating the amount of organic carbon leaving the upper water column and becoming sequestered in the deep ocean is a major challenge in our understanding the oceanic C cycle. This study investigate deep sediment trap material collected at a 5 day resolution over a 4 month period covering the bloom in the northern Scotia Sea. This region is charac...
Marine plastic pollution is a global and pervasive environmental issue. Knowledge on plastic degradation in natural settings is still very limited due to current technological limitations, hampering our understanding of plastic fate (including its breakdown into micro- and nanoplastics) and of its risk for marine ecosystems. Here we present the pro...
In the Southern Ocean, several zooplankton taxonomic groups, euphausiids, copepods, salps and pteropods, are notable because of their biomass and abundance and their roles in maintaining food webs and ecosystem structure and function, including the provision of globally important ecosystem services. These groups are consumers of microbes, primary a...
In 2017, the United Nations proclaimed a Decade of
Ocean Science for Sustainable Development (hereafter
referred to as the UN Ocean Decade) from 2021 until
2030 to support efforts to reverse the cycle of decline in
ocean health. To achieve this ambitious goal, this initiative
aims to gather ocean stakeholders worldwide behind a
common framework tha...
The polar plastics research community have recommended the spatial coverage of microplastic investigations in Antarctica and the Southern Ocean be increased. Presented here is a baseline estimate of microplastics in the nearshore waters of South Georgia, the first in situ study of the north-east coast of the island. Our results show that the microp...
In the Southern Ocean (SO), plastic debris has already been found in waters and sediments. Nanoplastics (<1 μm) are expected to be as pervasive as their larger counterparts, but more harmful to biological systems, being able to enter cells and provoke toxicity. In the SO, (nano)plastic pollution occurs concomitantly with other environmental threats...
In aquatic environments, plastic pollution occurs concomitantly with anthropogenic climate stressors such as ocean acidification. Within the Southern Ocean, Antarctic krill (Euphausia Superba) support many marine predators and play a key role in the biogeochemical cycle. Ocean acidification and plastic pollution have been acknowledged to hinder Ant...
As the remote Canadian Arctic Archipelago (CAA) becomes increasingly connected to the rest of the world, there is an impetus to monitor the possible impact of this connectivity. The potential for increases in localised sources of plastic pollution resulting from the increasing navigability of the remote north has yet to be explored. Here we investi...
A Correction to this paper has been published: https://doi.org/10.1038/s41467-021-22037-y
Antarctic krill play an important role in biogeochemical cycles and can potentially generate high-particulate organic carbon (POC) fluxes to the deep ocean. They also have an unusual trait of moulting continuously throughout their life-cycle. We determine the krill seasonal contribution to POC flux in terms of faecal pellets (FP), exuviae and carca...
Polar marine ecosystems may have higher sensitivity than other ecosystems to plastic pollution due to recurrent physical and biological features; presence of ice and high UV radiation, slow growth rates and weak genetic differentiation of resident biota, accumulation of persistent organic pollutants and heavy metals, and fast rates of warming and g...
Plastic debris has been identified as a potential threat to Antarctic marine ecosystems, however, the impact of nanoplastics (< 1 μm) is currently unexplored. Antarctic krill (Euphausia superba) is a keystone species of Southern Ocean pelagic ecosystems, which plays a central role in the Antarctic food webs and carbon (C) cycle. Krill has been show...
This study investigated the distribution of plastic debris from the Atlantic portion of the Sub-Antarctic to the Antarctic Peninsula. This region is home to some of the highest concentrations of zooplankton biomass but is also threatened by increasing shipping traffic from fishing and the growing tourism market. Samples were collected using a surfa...
Abstract. Shelled pteropods represent an excellent sentinel for indicating exposure to ocean acidification (OA). Here, for the first time, we characterise spring pteropod distribution throughout the Mediterranean Sea, a region that has been identified as a climate change hot-spot. The presence of a west–east natural biogeochemical gradient makes th...
Diel vertical migration is a widespread behaviour amongst zooplankton, yet its effect on the rate at which individuals respire remains poorly understood. To address this, we investigated the effect of short-term temperature change on the respiration rate of Euphausia triacantha , a common component of the Southern Ocean zooplankton and a prominent...
The potential for preservation of thecosome pteropods is thought to be largely governed by the chemical stability of their delicate aragonitic shells in seawater. However, sediment trap studies have found that significant carbonate dissolution can occur above the carbonate saturation horizon. Here we present the results from experiments conducted o...
Zooplankton fecal pellets (FPs) are important conduits of carbon from the surface to the deep ocean, as shown by their presence in deep-sea sediment traps. Zooplankton themselves are thought to play an important role in the breakdown and reworking of FPs as they sink, whilst processes such as diel vertical migration (DVM) may enhance the supply of...
The biological carbon pump drives a flux of particulate organic carbon (POC) through the ocean and affects atmospheric levels of carbon dioxide. Short term, episodic flux events are hard to capture with current observational techniques and may thus be underrepresented in POC flux estimates. We model the potential hidden flux of POC originating from...
Pteropods have been a key focus of ocean acidification studies during the last decade due to their fragile aragonite shells and key role they play in polar ecosystems. Pteropods collected at sea are typically preserved before analysis at onshore laboratories. Despite the importance placed on pteropods as a sentinel for the impact of ocean acidifica...
In this study, carbonate system properties were measured in the western Ross Sea (Antarctica) over the 2005-2006 and 2011-2012 austral summers with the aim of analysing their sensitivity to physical and biogeochemical drivers. Daily Advanced Microwave Scanning Radiometer 2 (AMSR2) sea ice concentration maps, obtained prior to and during the samplin...
The efficiency of deep-ocean CO2 sequestration is regulated by the relative balance between inorganic and organic carbon export respectively acting through the biological carbon pump (BCP) and the carbonate counter pump (CCP). The composition and abundance of calcifying species in the prevailing oceanic plankton community plays a major role in driv...
Natural gradients of pH in the ocean are useful analogues for studying the projected impacts of Ocean Acidification (OA) on marine ecosystems. Here we document the in situ impact of submarine CO2 volcanic emissions (CO2 vents) on live shelled-pteropods (planktonic gastropods) species Creseis conica in the Gulf of Naples (Tyrrhenian Sea, Mediterrane...
Plastic in the Oceans: Challenges and Solutions; Cambridge, United Kingdom, 7 March 2018
The abundance and flux of acantharian cysts were recorded for a period of 12 months from December 2012 to 2013 in a sediment trap deployed at 1500 m in the north-eastern Scotia Sea, Southern Ocean. Acantharia (radiolarian protists) are found globally, have very dense celestite skeletons, and form cysts which can sink rapidly through the water colum...
Natural iron fertilization downstream of Southern Ocean island plateaus supports large phytoplankton blooms and promotes carbon export from the mixed layer. In addition to sequestering atmospheric CO2, the biological carbon pump also supplies organic matter (OM) to deep-ocean ecosystems. Although the total flux of OM arriving at the seafloor sets t...
The dissolution of the delicate shells of sea butterflies, or pteropods, has epitomised discussions regarding ecosystem vulnerability to ocean acidification over the last decade. However, a recent demonstration that the organic coating of the shell, the periostracum, is effective in inhibiting dissolution suggests that pteropod shells may not be as...
The dissolution of the delicate shells of sea butterflies, or pteropods, has epitomised discussions regarding ecosystem vulnerability to ocean acidification over the last decade. However, a recent demonstration that the organic coating of the shell, the periostracum, is effective in inhibiting dissolution suggests that pteropod shells may not be as...
Early life stages of marine calcifiers are particularly vulnerable to climate change. In the Southern Ocean aragonite undersaturation events and areas of rapid warming already occur and are predicted to increase in extent. Here, we present the first study to successfully hatch the polar pteropod Limacina helicina antarctica and observe the potentia...
Natural iron fertilization downstream of Southern Ocean island plateaus support large phytoplankton blooms and promote carbon export from the mixed layer. In addition to sequestering atmospheric CO2, the biological carbon pump also supplies organic matter (OM) to deep-ocean ecosystems. Although the total flux of OM arriving at the seafloor sets the...
Antarctic krill (Euphausia superba) play a central role in the food web of the Southern Ocean, forming a link between primary production and large predators. Krill produce large, faecal pellets (FP) which can form a large component of mesopelagic particulate organic carbon (POC) fluxes. However, the patchy distribution of krill swarms, highly varia...
The impact of anthropogenic ocean acidification (OA) on marine ecosystems is a vital concern facing marine scientists and managers of ocean resources. Euthecosomatous pteropods (holoplanktonic gastropods) represent an excellent sentinel for indicating exposure to anthropogenic OA because of the sensitivity of their aragonite shells to the OA condit...
The faecal pellets (FPs) of zooplankton can be important vehicles for the transfer of particulate organic carbon (POC) to the deep ocean, often making large contributions to carbon sequestration. However, the routes by which these FPs reach the deep ocean have yet to be fully resolved. We address this by comparing estimates of copepod FP production...
The faecal pellets (FP) of zooplankton can be important vehicles for the transfer of particulate organic carbon (POC) to the deep ocean, often making large contributions to carbon sequestration. However, the routes by which these FP reach the deep ocean have yet to be fully resolved. We address this by comparing estimates of FP production to measur...
The effects of ocean acidification (OA) on the early recruitment of pteropods in the Scotia Sea, was investigated considering the process of spawning, quality of the spawned eggs and their capacity to develop. Maternal OA stress was induced on female pteropods (Limacina helicina antarctica) through exposure to present day pCO2 conditions and two po...
Fecal pellets (FP) are a key component of the biological carbon pump, as they can, under some circumstances, efficiently transfer carbon to depth. Like other forms of particulate organic carbon (POC), they can be remineralized in the ocean interior (particularly in the upper 200 m), or alternatively they can be preserved in the sediments. The contr...
Shelled pteropods are a group of nektonic molluscs that live in the upper ocean. They form their shells from aragonite, the more soluble form of calcium carbonate, and are abundant in polar waters where carbon dioxide is most soluble. When carbon dioxide dissolves in the ocean, it reacts with water, decreasing the concentration of carbonate ions, e...
The effects of ocean acidification (OA) on the early recruitment of pteropods in the Scotia Sea, was investigated considering the process of spawning, quality of the spawned eggs and their capacity to develop. Maternal OA stress was induced on female pteropods (Limacina helicina antarctica) through exposure to present day pCO2 conditions and two po...
Scarred shells of polar pteropod Limacina helicina collected from the Greenland Sea in June 2012 reveal a history of damage, most likely failed predation, in earlier life stages. Evidence of shell fracture and subsequent re-growth is commonly observed in specimens recovered from the sub-Arctic and further afield. However, at one site within sea-ice...
The northern Scotia Sea contains the largest seasonal uptake of atmospheric
carbon dioxide yet measured in the Southern Ocean. This study examines one
of the main routes by which this carbon fluxes to the deep ocean: through
the production of faecal pellets (FPs) by the zooplankton community. Deep
sediment traps were deployed at two sites with cont...
The northern Scotia Sea contains the largest seasonal uptake of
atmospheric carbon dioxide yet measured in the Southern Ocean. This
study examines one of the main routes by which this carbon fluxes to
the deep ocean, through the production of faecal pellets (FPs) by
the zooplankton community. Deep sediment traps were deployed in two
sites with cont...
The timing of vertical migration in planktonic foraminifera (ex. ontogenetic, diel) is still an open debate. This work aims to investigate the diel vertical migration (DVM) of Neogloboquadrina pachyderma (N. pachyderma) and Turborotalita
quinqueloba (T. quinqueloba) in the Arctic during the midnight sun. N. pachyderma and T. quinqueloba dominate th...
Anthropogenic carbon dioxide emissions induce ocean acidification, thereby reducing carbonate ion concentration, which may affect the ability of calcifying organisms to build shells. Pteropods, the main planktonic producers of aragonite in the worlds' oceans, may be particularly vulnerable to changes in sea water chemistry. The negative effects are...
The present study investigated the effects of ocean acidification and temperature increase on Neogloboquadrina pachyderma (sinistral), the dominant planktonic foraminifer in the Arctic Ocean. Due to the naturally low concentration of CO3 2- in the Arctic, this foraminifer could be particularly sensitive to the forecast changes in seawater carbonate...
The present study investigated the effects of ocean acidification and temperature increase on Neogloboquadrina pachyderma (sinistral), the dominant planktonic foraminifer in the Arctic Ocean. Due to the naturally low concentration of [CO3] 2- in the Arctic, this foraminifer could be particularly sensitive to the forecast changes in seawater carbona...
Anthropogenic carbon dioxide emissions induce ocean acidification, thereby reducing carbonate ion concentration, which may affect the ability of calcifying organisms to build shells. Pteropods, the main planktonic producers of aragonite in the worlds' oceans, may be particularly vulnerable to changes in sea water chemistry. The negative effects are...
The understanding of the role of the pteropods Limacina helicina in the ecosystem has become of greater interest as the debate on ocean acidification and its consequences for calcifying organisms has increased. Four incubation experiments were carried out in January and February 2006 in Terra Nova Bay Polynya (Ross Sea) to identify the faecal pelle...