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Marine phytoplankton contribute about one half of global primary production and play a key role in global biogeochemical cycles. High cell densities in extensive phytoplankton blooms are expected to be modified by global changes in ocean circulation and stratification, acidification and carbonation, solar radiation, temperature, and eutrophication. Although photochemical gas production from chromophoric dissolved organic matter (CDOM) has been widely studied, ultraviolet (UV) effects on emissions from phytoplankton cells themselves have not been fully explored. We therefore investigated UV-driven emissions of carbon monoxide (CO), carbon dioxide (CO2), methane (CH4), ethene (C2H4), ethane (C2H6), and nitrous oxide (N2O) from cell suspensions of 16 phytoplankton species and their filtrates under controlled experimental conditions. These gases make direct or indirect contributions to radiative forcing of the atmosphere or contribute to atmospheric chemistry including stratospheric ozone (O3) depletion. We observed production of CH4, CO, CO2, C2H4, and N2O from cell suspensions and CO, CO2, and N2O after 0.45 μm-filtration to remove phytoplankton cells. CH4 production was only observed with cells present, whereas N2O was still produced after filtration. Production of CO from filtrates was 30%–90% of that from cell suspensions in all but two species with a CO2:CO mole ratio from filtrates always below one. Our results clearly demonstrate a need to quantify the production potentials of these climate-relevant gases in situ under natural sunlight using key phytoplankton species, especially those forming blooms which are predicted to change in prevalence and distribution with future global change scenarios.

Temperate shelf seas are productive areas with the potential to export high quantities of particulate organic carbon (POC), as sinking particles, to the sediments or off-shelf to the open ocean. The amount of carbon which can be exported depends partly on the amount of POC produced and on the remineralization processes occurring on the sinking material. Here, we assessed the relative seasonal importance of microbial respiration and bacterial production associated with suspended, slow- and fast-sinking particle fractions. The three fractions were collected in the Celtic Sea above and below the seasonal thermocline in November 2014, April and July 2015 using Marine Snow Catchers. The slow-sinking fraction had higher microbial respiration and bacterial production rates than the fast-sinking fractions, and these two fractions sustained rates of microbial respiration and bacterial production between 1 and 3 orders of magnitude lower than the suspended fraction. This low contribution of the slow- and fast-sinking fractions was consistent with their low contribution to the POC concentration at the two depths sampled. The POC-specific respiration rates associated with the slow- and fast-sinking fractions were low (median 0.17 and 0.08 d−1, respectively), indicating low-sinking particle degradation. Our results indicate that ∼5% of the POC in surface waters can be exported below the thermocline.

SUMMARY Growth of the marine eustigmatophyte Nannochloropsis oculata (Droop) Hibberd was Followed through two periods of batch growth from stationary phase until cessation of net C-fixation. Growth continued for two generations after exhaustion of the N-source (100μM NH4+), with an increase in the cell C/N mass ratio from 6 to 28. N-deprived cells had a larger mean volume (130%) than N-replete cells. Intracellular concentrations of carotenoids and Chla correlated with cell-N until exhaustion of the N-source, when Chla ml−1 of culture declined significantly. The contribution of intracellular amino-N to cell-N was less than 3% throughout exponential and stationary phases. The major intracellular amino acids were glutamate (Glu), glutamine (Gln) and alanine; concentrations of tyrosine (on a population basis) increased steadily during N-deprivation. The intracellular concentrations of other amino acids showed fluctuations corresponding with changes in growth rate (e.g. arginine) or cell-N (e.g. glycine). The intracellular ratio of Gln/Glu reached a peak of more than 26 within 3 h of inoculation of stationary phase cells into fresh medium, before falling to around 0.6 during exponential growth, and then remained below 0.1 after NH4− exhaustion. Of the extracellular amino acids, concentrations of alanine and serine remained relatively constant throughout, while those of glycine, glutamate and of total dissolved free amino acids increased during exponential and early post-exponential phases, before levelling off at 1.4μM amino-N. The behaviour of Nannochloropsis oculata is contrasted with the growth and physiology of Isochrysis galbana

SUMMARY The marine phytoflagellate Isochrysis galbana Parke was followed through two consecutive cycles of ammoniumlimited growth. There was a significant (48 h) lag in cell division following the resupply of ammonium but no discernible lag in biomass growth, which led to a transient increase in the mean biomass per cell. Cell carbon and Coulter volume were linearly correlated. Net chlorophyll synthesis was closely linked to the absorption of extracellular N, while carotenoid synthesis continued until C fixation ceased. Photosynthetic activity (C fixation per unit chlorophyll) varied significantly with the cellular N: C ratio. A rapid rise in the ratio of glutamine to glutamate (01-6) during the first 24 h after nitrogen supply indicated a temporary imbalance in the flux of C and N into biomass synthesis. Intracellular ammonium accounted for less than 4 % of total cell N, while free intracellular amino acids accounted for 3-5 %. Nevertheless, cell numbers were able to double after the medium became depleted of ammonium, presumably by recycling and redistributing high molecular weight intracellular N.

Harmful algal bloom events are increasing in a number of water bodies around the world with significant economic impacts on the aquaculture, fishing and tourism industries. As well as their potential impacts on human health, toxin exposure from harmful algal blooms (HABs) has resulted in widespread morbidity and mortality in marine life, including top marine predators. There is therefore a need for an improved understanding of the trophic transfer, and persistence of toxins in marine food webs. For the first time, the concentrations of two toxin groups of commercial and environmental importance, domoic acid (DA) and saxitoxin (including Paralytic Shellfish Toxin (PST) analogues), were measured in the viscera of 40 different fish species caught in Scotland between February and November, 2012 to 2019. Overall, fish had higher concentrations of DA compared to PSTs, with a peak in the summer / autumn months. Whole fish concentrations were highest in pelagic species including Atlantic mackerel and herring, key forage fish for marine predators including seals, cetaceans and seabirds. The highest DA concentrations were measured along the east coast of Scotland and in Orkney. PSTs showed highest concentrations in early summer, consistent with phytoplankton bloom timings. The detection of multiple toxins in such a range of demersal, pelagic and benthic fish prey species suggests that both the fish, and by extension, piscivorous marine predators, experience multiple routes of toxin exposure. Risk assessment models to understand the impacts of exposure to HAB toxins on marine predators therefore need to consider how chronic, low-dose exposure to multiple toxins, as well as acute exposure during a bloom, could lead to potential long-term health effects ultimately contributing to mortalities. The potential synergistic, neurotoxic and physiological effects of long-term exposure to multiple toxins require investigation in order to appropriately assess the risks of HAB toxins to fish as well as their predators.

The IOC-ICES-PICES Harmful Algal Event Database (HAEDAT) was used to describe the diversity and spatiotemporal distribution of harmful algal events along the Atlantic margin of Europe from 1987 - 2018. The majority of events recorded are caused by Diarrhetic Shellfish Toxins (DSTs). These events are recorded annually over a wide geographic area from southern Spain to northern Scotland and Iceland, and are responsible for annual closures of many shellfish harvesting areas. The dominant causative dinoflagellates, members of the morphospecies ‘Dinophysis acuminata complex’ and D. acuta, are common in the waters of the majority of countries affected. There are regional differences in the causative species associated with PST events; the coasts of Spain and Portugal with the dinoflagellates Alexandrium minutum and Gymnodinium catenatum, north west France/south west England/south Ireland with A. minutum, and Scotland/Faroe Islands/Iceland with A. catenella. This can influence the duration and spatial scale of PST events as well as the toxicity of shellfish. The diatom Pseudo-nitzschia australis is the most widespread Domoic Acid (DA) producer, with records coming from Spain, Portugal, France, Ireland and the UK. Amnesic Shellfish Toxins (ASTs) have caused prolonged closures for the scallop fishing industry due to the slow depuration rate of DA. Amendments to EU shellfish hygiene regulations introduced between 2002 and 2005 facilitated end-product testing and sale of adductor muscle. This reduced the impact of ASTs on the scallop fishing industry and thus the number of recorded HAEDAT events. Azaspiracids (AZAs) are the most recent toxin group responsible for events to be characterised in the ICES area. Events associated with AZAs have a discrete distribution with the majority recorded along the west coast of Ireland. Ciguatera Poisoning (CP) has been an emerging issue in the Canary Islands and Madeira since 2004. The majority of aquaculture and wild fish mortality events are associated with blooms of the dinoflagellate Karenia mikimotoi and raphidophyte Heterosigma akashiwo. Such fish killing events occur infrequently yet can cause significant mortalities. Interannual variability was observed in the annual number of HAEDAT areas with events associated with individual shellfish toxin groups. HABs represent a continued risk for the aquaculture industry along the Atlantic margin of Europe and along the Atlantic margin of Europe and should be accounted for when considering expansion of the industry or operational shifts to offshore areas.

Rapid warming has been observed across the Arctic region in recent decades, resulting in a significant reduction in sea ice extent and duration which is most pronounced in the marginal ice zone. These sea ice changes and the resultant changes in ocean mixing are affecting nutrient supply, uptake and cycling and are predicted to have large-scale consequences for the distribution and magnitude of primary production throughout the Arctic Ocean. The objective of this study is to quantify the uptake of inorganic and organic nitrogen in the Barents Sea marginal ice zone during winter, spring and summer 2018, in the context of the seasonal transition in sea ice coverage and upper ocean dynamics.We conducted three cruises in January, April and June 2018 along a 30 °E transect covering the full range of sea ice conditions and water masses observed in the Barents Sea. We measured the concentration of inorganic and organic nitrogen compounds throughout the water column and conducted nitrogen uptake experiments on water samples taken from the euphotic zone using 15N-labelled nitrate, ammonium, urea and amino acids.These uptake rates are used to calculate nitrate-based new production and regenerated production based on ammonium, urea and amino acids, and these calculations are used to estimate the f-ratio. Here we will present initial results on the supply of inorganic and organic nitrogen forms and their uptake rates by different phytoplankton communities at different times of year. These rates and the derived f-ratio provide a measure for productivity of the ecosystem over the winter to summer transition. We will discuss the effects of sea ice cover and water mass structure with respect to the polar front on new production and phytoplankton community composition, which play an important role in regulating the magnitude of primary production in the Barents Sea. These results will contribute to our understanding of how biological and biogeochemical processes in the Arctic may respond to ongoing changes in the physical environment as climate change proceeds.

Fjordic coastlines provide an ideal protected environment for both finfish and shellfish aquaculture operations. This study reports the results of a cruise to the Scottish Clyde Sea, and associated fjordic sea lochs, that coincided with blooms of the diarrhetic shellfish toxin producing dinoflagellate Dinophysis acuta and the diatom genus Chaetoceros, that can generate finfish mortalities. Unusually, D. acuta reached one order of magnitude higher cell abundance in the water column (2840 cells L−1) than the more common Dinophysis acuminata (200 cells L−1) and was linked with elevated shellfish toxicity (maximum 601 ± 237 μg OA eq/kg shellfish flesh) which caused shellfish harvesting closures in the region. Significant correlations between D. acuta abundance and that of Mesodinium rubrum were also observed across the cruise transect potentially supporting bloom formation of the mixotrophic D. acuta. Significant spatial variability in phytoplankton that was related to physical characteristics of the water column was observed, with a temperature-driven frontal region at the mouth of Loch Fyne being important in the development of the D. acuta, but not the Chaetoceros bloom. The front also provided important protection to the aquaculture located within the loch, with neither of the blooms encroaching within it. Analysis based on a particle-tracking model confirms the importance of the front to cell transport and shows significant inter-annual differences in advection within the region, that are important to the harmful algal bloom risk therein.

8 pages, 1 figures, 4 tables, supplementary material https://doi.org/10.1016/j.hal.2020.101901.-- This paper contributes to the implementation of the objectives of the IOC-SCOR GlobalHAB international programme (www.globalhab.info) concerning HABs and Human Health, Exposure to harmful algal blooms (HABs) can lead to well recognised acute patterns of illness in humans. The objective of this scoping review was to use an established methodology and the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) reporting framework to map the evidence for associations between marine HABs and observed both acute and chronic human health effects. A systematic and reproducible search of publications from 1985 until May 2019 was conducted using diverse electronic databases. Following de-duplication, 5,301 records were identified, of which 380 were included in the final qualitative synthesis. The majority of studies (220; 57.9%) related to Ciguatera Poisoning. Anecdotal and case reports made up the vast majority of study types (242; 63.7%), whereas there were fewer formal epidemiological studies (35; 9.2%). Only four studies related to chronic exposure to HABs. A low proportion of studies reported the use of human specimens for confirmation of the cause of illness (32; 8.4%). This study highlighted gaps in the evidence base including a lack of formal surveillance and epidemiological studies, limited use of toxin measurements in human samples, and a scarcity of studies of chronic exposure. Future research and policy should provide a baseline understanding of the burden of human disease to inform the evaluation of the current and future impacts of climate change and HABs on human health, The research was funded in part by the UK Natural Environment Research Council (NERC) Case PhD in Climate Change, Harmful Algal Blooms and Human Health; the UK National Institute for Health Research Health Protection Research Unit (NIHR HPRU) in Environmental Change and Health at the London School of Hygiene and Tropical Medicine in partnership with Public Health England (PHE), and in collaboration with the University of Exeter, University College London, and the Met Office; the UK Medical Research Council (MRC) and UK Natural Environment Research Council (NERC) for the MEDMI Project (https://www.data-mashup.org.uk); and the European Union's Horizon 2020, Grant/ Award Number: 774567 (SOPHIE Projecthttps://sophie2020.eu) and 666773 (BlueHealth Projecthttps://bluehealth2020.eu); UK Global Challenges Research Fund (GCRF) via the United Kingdom Research and Innovation (UKRI) under grant agreement reference NE/P021107/1 to the Blue Communities project; and the UKRI grants OFF-Aqua BB/S004246/, CAMPUS NE/R00675X/11 and the Atlantic Area Interreg project PRIMROSE, With the funding support of the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000928-S), of the Spanish Research Agency (AEI)

1 pages, 1 figure, 1 table, There is increasing concern that accelerating environmental change attributed to human-induced warming of the planet may substantially alter the patterns, distribution and intensity of Harmful Algal Blooms (HABs). Changes in temperature, ocean acidification, precipitation, nutrient stress or availability, and the physical structure of the water column all influence the productivity, composition, and global range of phytoplankton assemblages, but large uncertainty remains about how integration of these climate drivers might shape future HABs. Presented here are the collective deliberations from a symposium on HABs and climate change where the research challenges to understanding potential linkages between HABs and climate were considered, along with new research directions to better define these linkages. In addition to the likely effects of physical (temperature, salinity, stratification, light, changing storm intensity), chemical (nutrients, ocean acidification), and biological (grazer) drivers on microalgae (senso lato), symposium participants explored more broadly the subjects of cyanobacterial HABs, benthic HABs, HAB effects on fisheries, HAB modelling challenges, and the contributions that molecular approaches can bring to HAB studies. There was consensus that alongside traditional research, HAB scientists must set new courses of research and practices to deliver the conceptual and quantitative advances required to forecast future HAB trends. These different practices encompass laboratory and field studies, long-term observational programs, retrospectives, as well as the study of socioeconomic drivers and linkages with aquaculture and fisheries. In anticipation of growing HAB problems, research on potential mitigation strategies should be a priority. It is recommended that a substantial portion of HAB research among laboratories be directed collectively at a small sub-set of HAB species and questions in order to fast-track advances in our understanding. Climate-driven changes in coastal oceanographic and ecological systems are becoming substantial, in some cases exacerbated by localized human activities. That, combined with the slow pace of decreasing global carbon emissions, signals the urgency for HAB scientists to accelerate efforts across disciplines to provide society with the necessary insights regarding future HAB trends, KD was supported by the BBSRC/NERC sustainable aquaculture programme grant BB/M025934/1 and the NWE Europe Interreg project PRIMROSE). SS was supported by the Academy of Finland (grant 259357). EB’s attendance was funded by Spanish MINECO through the OstreoRisk (CTM2014-53818-R) project. VA’s attendance to the workshop was funded in the framework of M3-HABs project (ENPI CBC Mediterranean Sea Basin Programme, www.m3-habs.net). Funding was provided by the Commonwealth Scientific and Industrial Research Organisation of Australia to allow PT to attend, With the funding support of the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000928-S), of the Spanish Research Agency (AEI)

Funding: BBSRC/NERC (ref. BB/M026620/01). Isotope analysis was supported by NERC Life Science Mass Spectrometry Facility (CEH_L_098_11_2015). Fjords have been described as hotspots for carbon burial, potentially playing a key role within the carbon cycle as climate regulators over multiple timescales. Nevertheless, little is known about the long-term fate of the carbon that may become stored in fjordic sediments. One of the main reasons for this knowledge gap is that carbon arriving on the seafloor is prone to post-depositional degradation, posing a great challenge when trying to discriminate between an actual change in the carbon deposition rate and post-depositional carbon loss. In this study, we evaluate the use of modern benthic foraminifera as bio-indicators of organic carbon content in six voes (fjords) on the west coast of Shetland. Benthic foraminifera are known to be sensitive to changes in organic carbon content in the sediments, and changes in their assemblage composition therefore reflect synchronous variations in the quantity and quality of carbon reaching the seafloor. We identified four environments based on the relationship between benthic foraminiferal assemblages and organic carbon content in the sediments: (1) land-locked regions influenced by riverine and/or freshwater inputs of organic matter, namely the head of fjords with a restricted geomorphology; (2) stressed environments with a heavily stratified water column and sediments rich in organic matter of low nutritional value; (3) depositional environments with moderate organic content and mild or episodic current activity; and (4) marginal to coastal settings with low organic content, such as fjords with an unrestricted geomorphology. We conclude that foraminifera potentially provide a tool to disentangle primary organic carbon signals from post-depositional degradation and loss of organic carbon because of their environmental sensitivity and high preservation potential in the sedimentary record. Publisher PDF

Fjordic coastlines provide sheltered locations for finfish and shellfish aquaculture, and are often subject to harmful algal blooms (HABs) some of which develop offshore and are then advected to impact nearshore aquaculture. Numerical models are a potentially important tool for providing early warning of such HAB events. However, the complex topography of fjordic shelf regions is a significant challenge to modelling. This is frequently compounded by complex bathymetry and local weather patterns. Existing structured grid models do not provide the resolution needed to represent these coastlines in their wider shelf context. In a number of locations advectively transported blooms of the ichthyotoxic dinoflagellate Karenia mikimotoi are of particular concern for the finfish industry. Here were present a novel hydrodynamic model of the coastal waters to the west of Scotland that is based on unstructured finite volume methodology, providing a sufficiently high resolution hydrodynamical structure to realistically simulate the transport of particles (such as K. mikimotoi cells) within nearshore waters where aquaculture sites are sited. Model–observation comparisons reveal close correspondence of tidal elevations for major semidiurnal and diurnal tidal constituents. The thermohaline structure of the model and its current fields are also in good agreement with a number of existing observational datasets. Simulations of the transport of Lagrangian drifting buoys, along with the incorporation of an individual-based biological model, based on a bloom of K. mikimotoi, demonstrate that unstructured grid models have considerable potential for HAB prediction in Scotland and in complex topographical regions elsewhere.

The “Applied Simulations and Integrated Modelling for the Understanding of Harmful Algal Blooms” (Asimuth) project sought to develop a harmful algal bloom (HAB) alert system for Atlantic Europe. This was approached by combining, at a national or regional level, regulatory monitoring phytoplankton and biotoxin data with satellite remote sensing and other information on current marine conditions, coupled with regional scale models that included a representation of HAB transport. Synthesis of these products was achieved by expert interpretation within HAB risk alert bulletins that were prepared on a regular basis (typically weekly) for use by the aquaculture industry. In this preface to the Asimuth Special Issue we outline the main HAB species of concern in the region and the strengths and limitations of different methodologies to provide early warning of their blooms.

The ‘English’ have an ambiguous relationship with the language of their nearest neighbour, France. There is a history, ‘1066 and all that’. Christmas Day 2016 saw the 950th anniversary of the crowning at Westminster Abbey of the French Duke William of Normandy as King of England (not, please note, of ‘Britain’); William having defeated King Harold – and so the very last ‘English’ monarch – at the battle of Hastings. (The other ‘nations’ of these European off-shore islands have different trajectories.) Sooner or later the English at least would have to come to terms with French.

Shellfish production is an important activity for the economy of many countries. As well as its direct value, it helps to stabilize communities in rural areas characterized by limited job opportunities. It is also important for consumers who recognize shellfish as a healthy product that gains its nutrition from natural plankton without the need for fertilizers, chemical treatments or other anthropogenic intervention typical of terrestrial agriculture or other marine aquaculture. Nevertheless, global shellfish fisheries are under threat from harmful algal blooms (HABs) and related biotoxins, whose production is potentially exacerbated by global changes. This research provides evidence of economic impacts on Scottish shellfish farms in the last 10 years caused by HABs and their associated biotoxins. In contrast to previous approaches that have focused on variation in production as a function of temporal trends and blooms events, we use a production function approach to show which input factors (labour, capital, climate variables, concentration of biotoxins) have an effect on production. Results show that diarrhoetic shellfish toxins produced by the genera Dinophysis are most significant. A 1% change in the production of these biotoxins reduces shellfish production by 0.66%, with an average yearly negative variation in production of 15% (1,080 ton) and an economic loss (turnover) of £ (GBP) 1.37 m per year (in 2015 currency) over a national annual industry turnover of ~ £ 12 m. The production function approach is coupled with a multivariate time series model (VAR) capturing the statistical relationship between algal concentration, information on climatic variables and biotoxins to forecast the damage to shellfish production from HABs. This provides producers and regulators with the economic information to plan temporal and spatial mitigating measures necessary to limit damages to production by comparing the costs of these measures with the costs of lost production.

Remote sensing of the marine coastal environment is useful for obtaining information about processes occurring within it. Monitoring has traditionally been carried out in situ, before investment increased in remote techniques such as manned planes and satellites. This paper proposes the use of remotely piloted aircraft systems (RPAS) as an alternative platform, with an aim of increasing the spectral, spatial and temporal resolution of data whilst reducing the associated costs and risks. A custom-built ‘spectro-copter’ system, comprising of an integrated dual field-of-view, miniaturised, hyper-spectral spectrometer aboard a purpose-built quadcopter is presented, developed at the Scottish Association for Marine Science (SAMS), Oban. This has been produced with a view to investigating reflectance from Scottish coastal waters, which can give inferences as to the concentrations of various constituents present [1], [2]. Initial test flights show the ‘spectro-copter’ system is capable of flights of $\sim 20$ minutes, sufficient for meaningful data collection, despite late adjustments incurring increased weight and an associated reduction in efficiency. Early results demonstrate that the setup is capable of discerning differences in $R$ at a high spectral resolution. Further work is ongoing in order to assess the capacity for establishing this equipment as a routine technique for the monitoring of coastal harmful algal blooms (HAB), which currently relies upon physical sampling in combination with satellites. HAB events are noted to be increasing in severity and frequency [3], [4], with knock-on health and economic impacts, particularly for the rising aquaculture industry in Scottish coastal waters [5]. Therefore advancement of an alternative, affordable technique would be extremely beneficial.

As the official control laboratory for marine biotoxins within Great Britain, the Centre for Environment, Fisheries and Aquaculture Science, in conjunction with the Scottish Association for Marine Science, has amassed a decade’s worth of data regarding the prevalence of the toxins associated with Amnesic Shellfish Poisoning within British waters. This monitoring involves quantitative HPLC-UV analysis of shellfish domoic acid concentration, the causative toxin for Amnesic Shellfish Poisoning, and water monitoring for Pseudo-nitzschia spp., the phytoplankton genus that produces domoic acid. The data obtained since 2008 indicate that whilst the occurrence of domoic acid in shellfish was generally below the maximum permitted limit of 20 mg/kg, there were a number of toxic episodes that breached this limit. The data showed an increase in the frequency of both domoic acid occurrence and toxic events, although there was considerable annual variability in intensity and geographical location of toxic episodes. A particularly notable increase in domoic acid occurrence in England was observed during 2014. Comparison of Scottish toxin data and Pseudo-nitzschia cell densities during this ten-year period revealed a complex relationship between the two measurements. Whilst the majority of events were associated with blooms, absolute cell densities of Pseudo-nitzschia did not correlate with domoic acid concentrations in shellfish tissue. This is believed to be partly due to the presence of a number of different Pseudo-nitzschia species in the water that can exhibit variable toxin production. These data highlight the requirement for tissue monitoring as part of an effective monitoring programme to protect the consumer, as well as the benefit of more detailed taxonomic discrimination of the Pseudo-nitzschia genus to allow greater accuracy in the prediction of shellfish toxicity.

© 2019 The Authors., Circulating neutrophils are, by necessity, quiescent and relatively unresponsive to acute stimuli. In regions of inflammation, mediators can prime neutrophils to react to acute stimuli with stronger proinflammatory, pathogen‐killing responses. In neutrophils G protein‐coupled receptor (GPCR)‐driven proinflammatory responses, such as reactive oxygen species (ROS) formation and accumulation of the key intracellular messenger phosphatidylinositol (3,4,5)‐trisphosphate (PIP3), are highly dependent on PI3K‐γ, a Ras‐GTP, and Gβγ coincidence detector. In unprimed cells, the major GPCR‐triggered activator of Ras is the Ras guanine nucleotide exchange factor (GEF), Ras guanine nucleotide releasing protein 4 (RasGRP4). Although priming is known to increase GPCR–PIP3 signaling, the mechanisms underlying this augmentation remain unclear. We used genetically modified mice to address the role of the 2 RasGEFs, RasGRP4 and son of sevenless (SOS)1/2, in neutrophil priming. We found that following GM‐CSF/TNFα priming, RasGRP4 had only a minor role in the enhanced responses. In contrast, SOS1/2 acquired a substantial role in ROS formation, PIP3 accumulation, and ERK activation in primed cells. These results suggest that SOS1/2 signaling plays a key role in determining the responsiveness of neutrophils in regions of inflammation., This work was supported by grants from the Biotechnology and Biological Sciences Research Council (BB/J004456/1 and BB/P013384/1).

Our model framework provides an adaptable and robust methodology for investigating how environmental processes affect the dispersal of marine organisms. It also provides a rapid and cost-effective approach to answering many questions faced by ecologists and local industries alike, even in situations where ecological data are sparse or unavailable.

Cyclic imines (CIs) are a group of phytoplankton produced toxins related to shellfish food products, some of which are already present in UK and European waters. Their risk to shellfish consumers is poorly understood, as while no human intoxication has been definitively related to this group, their fast acting toxicity following intraperitoneal injection in mice has led to concern over their human health implications. A request was therefore made by UK food safety authorities to examine these toxins more closely to aid possible management strategies. Of the CI producers only the spirolide producer Alexandrium ostenfeldii is known to exist in UK waters at present but trends in climate change may lead to increased risk from other organisms/CI toxins currently present elsewhere in Europe and in similar environments worldwide. This paper reviews evidence concerning the prevalence of CIs and CI-producing phytoplankton, together with testing methodologies. Chemical, biological and biomolecular methods are reviewed, including recommendations for further work to enable effective testing. Although the focus here is on the UK, from a strategic standpoint many of the topics discussed will also be of interest in other parts of the world since new and emerging marine biotoxins are of global concern.

Berdalet, Elisa ... et al.-- 23 pages, 3 figures, The idea for establishment of the GlobalHAB Programme arose at the final Synthesis Open Science Meeting (OSM) of the Global Ecology and Oceanography of Harmful Algal Blooms (GEOHAB) Programme in Paris, in April 2013 (GEOHAB 2014). Participants at the meeting evaluated and synthesized the outcomes of GEOHAB and agreed that international coordination of HAB science was still needed to increase understanding of these events and how to mitigate their impacts on humans and aquatic ecosystems. In 2015, the GlobalHAB Programme was formally adopted by the two cosponsors, the Intergovernmental Oceanographic Commission (IOC) of UNESCO [through the Intergovernmental Panel on Harmful Algal Blooms (IPHAB)] and the Scientific Committee on Oceanic Research (SCOR), and was also endorsed by the International Atomic Energy Agency (IAEA). IOC and SCOR appointed a Scientific Steering Committee (SSC) for the new GlobalHAB Programme in 2015, which met for the first time in March 2016 to initiate the development of the GlobalHAB Science and Implementation Plan that is summarized in this chapter. [...]

Water quality in Tolo Harbour and Channel (Tolo) has been improved since 1998 after the diversion of sewage effluent. However, it remains poorly understood how nutrient loading reduction has impacted the phytoplankton community. To evaluate this, we applied a Phytoplankton Community Index PI(mp) to the 23-year data (1991-2013) at inner (TM4) and outer (TM8) sites in Tolo, with the former being more eutrophic than the latter. The results show that 1) the phytoplankton community changed with time after sewage diversion; 2) "diatoms and dinoflagellates" were better indicators of nutrient impact than "autotrophic/mixotrophic and heterotrophic dinoflagellates"; 3) the rate of recovery differed between the two stations, but both reached a similar state at a similar time; 4) seasonality of the phytoplankton community showed greater disturbance in spring than in other seasons. Our findings indicate that the nutrient reduction in the Tolo resulted in a positive change in the phytoplankton community.

Berdalet, Elisa ... et al.-- Special issue on International Cooperation in Harmful Algal Bloom Science.-- 12 pages, 6 figures, From 1998 to 2013, the international community of scientists researching harmful algal blooms (HABs) in marine systems worked through the Intergovernmental Oceanographic Commission (IOC) of UNESCO and the Scientific Committee on Oceanic Research (SCOR) to better understand the ecological and oceanographic controls on these natural events that cause harm to humans and ecosystems. During this period, IOC and SCOR cosponsored the Global Ecology and Oceanography of Harmful Algal Blooms (GEOHAB) program to facilitate progress in HAB research, observations, and modeling. In 2016, building on the foundation provided by GEOHAB, IOC and SCOR launched a new HAB project design to extend research into freshwater systems and address several topics related to the effects of HABs on human society now and in a rapidly changing world, The GlobalHAB Scientific Steering Committee acknowledges the financial support provided by IOC and by SCOR through Grant OCE-1546580 from the US National Science Foundation, and from ICES, IPHAB, ISSHA, PICES, and the Scottish Association of Marine Science

Harmful algal blooms (HABs) are thought to be increasing in coastal waters worldwide. Anthropogenic nutrient enrichment has been proposed as a principal causative factor of this increase through elevated inorganic and/or organic nutrient concentrations and modified nutrient ratios. We assess: 1) the level of understanding of the link between the amount, form and ratio of anthropogenic nutrients and HABs; 2) the evidence for a link between anthropogenically generated HABs and negative impacts on human health; and 3) the economic implications of anthropogenic nutrient/HAB interactions. We demonstrate that an anthropogenic nutrient-HAB link is far from universal, and where it has been demonstrated, it is most frequently associated with high biomass rather than low biomass (biotoxin producing) HABs. While organic nutrients have been shown to support the growth of a range of HAB species, insufficient evidence exists to clearly establish if these nutrients specifically promote the growth of harmful species in preference to benign ones, or if/how they influence toxicity of harmful species. We conclude that the role of anthropogenic nutrients in promoting HABs is site-specific, with hydrodynamic processes often determining whether blooms occur. We also find a lack of evidence of widespread significant adverse health impacts from anthropogenic nutrient-generated HABs, although this may be partly due to a lack of human/animal health and HAB monitoring. Detailed economic evaluation and cost/benefit analysis of the impact of anthropogenically generated HABs, or nutrient reduction schemes to alleviate them, is also frequently lacking.