Seabed sediment represents a significant sink for carbon (C) and represents a major natural asset. Bottom-trawl fishing provides a quarter of global seafood but is also the most extensive anthropogenic physical disturbance to sediment C stocks with recent evidence suggesting that seabed disturbance could result in significant greenhouse gas release from the seabed and to the atmosphere. There are major uncertainties in our understanding of the effect of disturbance on seabed C stores and air/sea CO2 fluxes (in both magnitude and direction). Consequently, the impact of seabed disturbances on C are largely unquantified and currently unregulated. This project will determine how the disturbance associated with bottom trawling modifies C storage, cycling and air/sea CO2 fluxes. For the first time, the impact of trawling on sediment-water and air-sea CO2 exchange will be assessed holistically, providing essential guidance on seabed activity management policies that mitigate climate impacts and help achieve net-zero. The project will answer all four questions defined in the Highlight Topic call: How do fishing gear, trawling frequency and the sedimentary environment affect the potential for marine sediments to act as a net source of CO2? How does C resuspended due to trawling modulate seawater chemistry and what is the fate of the resuspended C? How do horizontal and vertical mixing, water column production and respiration affect the potential for trawl-driven biogeochemical change to result in impacts on air-sea exchanges? Will management interventions result in the reduction of C loss and CO2 emissions and recovery of seabed sediment C stocks? The project comprises of 4 integrated work packages (WPs) that directly address these 4 questions. WP1 will characterise sediment pore waters and quantify the stocks of POC and PIC in the sediment and will identify how trawl gears affect the fluxes of C under different environmental settings. WP2 will characterise changes in the water column and suspended C and sediment and establish its fate in the water column after trawl disturbance. WP3 will quantify the exchange of sub-surface trawl plumes with the surface mixed layer and resultant seawater CO2 and air/sea fluxes. WP1-3 will generate novel insights about the mechanisms through which disturbance affects C fluxes and transformations. A focussed campaign of ship-based experiments will be used to inform and improve model assessments. We selected four representative sites that allow understanding of processes in contrasting environmental settings. The 3 integrated WPs will inform and improve models, which will be used to upscale and extend the spatial and temporal assessment of trawling impacts. These spatial assessments will feed into WP4, which will evaluate and identify the most effective seabed C stock management measures in collaboration with stakeholders from policy, fishing industry, eNGOs and green finance. This research will link processes, impact and mitigation of CO2 emissions due to seabed disturbance. The outcomes of the research will inform environmental solutions by avoiding emissions from seabed sediments while maintaining food production, which sits at the centre of the NERC, UKRI, DEFRA and UK strategies for clean growth and achieving net-zero. This project will make a step change in our understanding of how trawling impacts C dynamics in shelf seas and will diminish the risk of under-valuing natural climate regulation by facilitating cost-benefit analysis and risk assessments.

Lake systems play a fundamental role in storing and providing freshwater and food, in supporting recreation and in protecting species diversity. However, the stability of these ecosystem services can be undermined by the increased demands society makes upon these systems and changes in atmospheric composition and lake water balance that arise through a societal-mediated changing climate. To safeguard against such loss of functioning there is in place legally-binding national and European directives that set stringent targets for water quality and biodiversity. Meeting these targets requires a detailed understanding of lake processes that in turn requires measurements at an appropriate temporal scale. Traditional monitoring, of at best weekly-fortnightly intervals, is sufficient to record seasonal change but cannot resolve the processes driving many aspects of lake function. To resolve these processes we need to 'hear every note in the full symphony of lake functioning', with such resolution only viable through semi-continuous measurement of parameters that are key reflectors of lake functioning. We are fortunate that deployed in eleven lakes across the UK, of different size, altitude, latitude and nutrient status, are basic systems automated to make such measurements, Automatic Water Quality Monitoring Stations (AWQMS). However at present, most buoys are restricted to a meteorological station and temperature measurements. A few have other probes to measure water quality, but these are subject to biofouling which could compromise the data. At present, the data are mainly downloaded by telemetry to the host-site via a range of procedures. Thus we are not utilising advances in data-logger-, computer- and sensor-technology to measure automatically at high frequency and 'hear the full symphony'. We propose to change this by installing stable, state-of-the-art sensor technology, with mechanical devices to minimise biofouling. Further, we will maximise the value of generating this high frequency data by linking together the lakes in a sensor network to deliver quality-controlled data onto the internet for analysis by project partners, the wider scientific community and the general public. Such infrastructure investment needs to reflect the need for high quality measurement from science-driven agendas. We will demonstrate such a network supports these agendas through the following projects: DST1: Real-time forecasting of lake behaviour: We will incorporate the real-time data available from the sensor network into a forecast system for lake phytoplankton behaviour and, in particular, to provide warning for the onset of phytoplankton blooms. DST2: The effect of meteorology on the fate of carbon within lakes: We will track pool and flux variability of dissolved carbon dioxide over daily to seasonal time scales. By relating these measurements to meteorological and within-lake physico-chemical measurements within and between sites we are better equipped to define critical controls on the lake carbon cycle. DST3: The level of regional coherence in sub-seasonal timescales: Lakes can show a regionally coherent response e.g. strong links exist between air and surface water temperature; large-scale weather patterns such as the position of north wall of the Gulf Stream have also been shown to influence directly the regional coherence of lakes. Use of high resolution data to examine coherence in lake temperatures has just begun but as yet no-one has investigated coherence of biological, chemical or wider physical variables on these short time-scales, an approach which is viable through this network. In summary, this sensor network of AWQMSs, offering detail of observation through high resolution data generation and the new instrumentation will demonstrate not only the value of observing the environment remotely and in detail, but the benefit from integration systems to offer real advances in environmental science.

Algae are present in nearly every body of water on the surface of the earth. These microscopic organisms produce roughly half of the oxygen on earth, and are vital to life on the planet. However, algae can also cause significant and expensive damage to their ecosystem, to human health, and to aquaculture stocks when the local environment changes and promotes the rapid growth of a large mass of algae, known as a bloom. Factors such as the concentration of nutrients, temperature, light conditions, and intentional or unintentional interventions by humans or other species all affect the dynamics of algae species and lead to the formation of harmful algal blooms (HABs). In the aquaculture context, HABs present a major health and economic hazard. Severe human health problems can arise from the consumption of shellfish which have been impacted by blooms of toxin-producing algae. These blooms also cause negative economic impacts on aquaculture through aquaculture stock mortality and through temporary site closures and bans on harvesting due to local algae prevalence. Large-scale mortalities of cultured fish due to algae blooms have been reported across the world and financial losses per large episode can range into the tens of millions of pounds. Monitoring of phytoplankton and of the toxins they produce has been undertaken in various forms in the UK for some decades but manual sampling and subsequent off-site analysis can be slow to identify areas with upcoming or rapidly-changing problems. Microscopy, the current standard for performing algae counts, requires trained personnel both in collection and particularly in analysis, and imposes a necessary delay as samples need to be preserved and transported to an analytical facility. The overall objective of this project is to develop new technology to decrease the economic losses and health risks caused by HABs by decreasing the costs of monitoring algae growth in real-time. This technology will complement and address shortcomings in existing monitoring techniques by providing low-cost, high resolution independent data. The PhytoMOPS technology is based on previous lab-based research demonstrating that algal cells could be sorted, counted, and classified using carefully-designed microfluidic channels combined with low-cost optical readouts. The sorting technique, known as "inertial microfluidics", relies on a carefully-designed channel geometry and flow rate to sort cells by shape and size. In this project, we will design a novel optical measurement section after the cell sorting region, in which the microalgal cells are counted and classfied according to their size, shape, and optical absorption properties. The technology will initially be built and evaluated in the lab where the results will be used to develop analytical methods for interpreting the data. In order to be able to make measurements directly in the water, we will adapt the National Oceanography Centre's (NOC's) water chemistry sensor platform which has already been used for long-term autonomous measurements in a wide range of harsh and inaccessible environments. We will combine the well-engineering NOC platform (including microfluidic chips, pumps, valves, and control/communication electronics) with the algae sorting technology to produce a deployable system capable of acting as a standalone, low-cost, low-power monitor of algal species dynamics for early warning of HABS formation. Lastly, this project involves initial field tests of the system. The deployments will be facilitated by two active HAB monitoring organisations who are also providing expert advice throughout the project: the Scottish Assocation for Marine Science and the Agri-Food Bioscience Institute (North Ireland). The system will will be compared directly against manual sampling and existing algal monitoring technology and will be be evaluated for its technical suitability, usability, and long-term potential.

The 2007 floods prompted the UK Government's "Pitt review", which came up with the idea that we need to start to deal with the causes of flooding upstream of the affected communities, rather than rely solely on the downstream engineering solutions. This stimulated a range of organisations to introduce "natural" features into the landscape that may have benefits in terms of reducing flooding (so called "Natural Flood Management, NFM"). Having introduced features these organisations, and local stakeholders working with them, are increasingly asking "Are these features working?" This has highlighted to funders, those implementing the features and scientists alike that there are gaps in the evidence of how individual features (e.g. a single farm pond or a small area of tree planting) work and what are potential downstream benefits for communities at risk of flooding. Stakeholders want both questions answered at the same time, making this one of the most important academic challenges for hydrological scientists in recent years. The only way to quantify the effects of many individual features at larger scales is to use computer models. To be credible, these models also need to produce believable results at individual feature scales. Meeting this challenge is the focus of this research project. Consequently, our primary objective is to quantify the likely effectiveness of these NFM features for mitigating flood risk at large catchment scales in the most credible way. In this context, credibility means being transparent and rigorous in the way that we deal with what we do know and what we don't know when addressing this problem using models. In doing this we need to address particular scientific challenges in the following ways: * We need to show that our models are capable of reproducing downstream floods while at the same time matching observed local hydrological phenomena, such as patterns of soil saturation. Integral to our methodology are observations of these local phenomena to further strengthen the credibility of the modelling. * We use the same models to predict NFM effects by changing key model components. These changes to the components are made in a rigorous way, initially based upon the current evidence. * As evidence of change is so critical, our project necessarily includes targeted experimental work to address some of the serious evidence gaps, to significantly improve the confidence in the model results. * This rigorous strategy provides us with a platform for quantifying the magnitude of benefit that can be offered by different spatial extents of NFM implementation across large areas. By addressing these scientific goals we believe that we can deliver a step change in the confidence of our quantification of the likely effectiveness of NFM measure for mitigating flood risk at large catchment scales.

Shallow seas, the Shelf Seas, surround almost all of the Earth's land masses. On average shelf seas are hundreds of meters deep, compared to the average depth of the ocean of nearly four kilometres. Shelf Seas may be as narrow as a few kilometres, or as wide as hundreds of kilometres and together they occupy only a tenth of the watery part of the world. Yet they exert an effect on humanity far out of proportion to their mere size. Shelf Seas around the UK and western Europe are particularly wide (10s to 100s km) and shallow (around 150m); they are beset by strong tides, westerly winds, and fed by the warm waters of the NE Atlantic. From the smallest plant life, phyto-plankton, to the fish, UK Shelf Seas are highly biologically productive: nine tenths of the world's commercial fish catches come from shelf seas. This high productivity is fuelled to the greatest extent by the movement of nutrient-rich ocean waters onto the Shelf Seas. However, the step seabed slope (the Shelf Edge), which marks a narrow zone separating ocean from shelf, acts to reduce the movement of water from ocean to shelf (and visa versa); major ocean currents do not like to cross a sloping seabed. This restriction to exchange, however, breaks down when oceanic flows feel the wind or the seabed, or vary more rapidly than daily or over distances shorter that a few tens of kilometres. The shelf edge is therefore seen as the controlling gateway to exchange between ocean and shelf, and the gatekeepers of that exchange are flows which change quickly, or lie at the very surface or at the very bottom of the sea. This makes the gatekeepers of exchange difficult to measure, and as a result we know very little about how the gatekeeper processes change from one season to another and from one year to another. FASTNEt will bring together the strongest possible UK team of Physical Oceanographers to tackle this challenge using state-of-the art observational technologies, and a range of predictive modelling approaches. Two research ship expeditions will study the details of the gatekeeper processes, aided by satellite tracked drifting buoy, fluorescent dyes, and unmanned mini-submarines. Instruments will be left in place over winter to record changes brought by winter storms, and a fleet of unmanned submarines will visit these instruments in conditions no ship could operate in, and is so doing fill a huge gap in our understanding. We will take the information gathered from the submarines, drifters, satellite pictures and ships and test our understanding of the gatekeeper processes, improve models designed to simulate these processes. We will then work with the National Centre for Ocean Forecasting to help improve our ability to provide forecasts of the conditions of the seas surrounding the United Kingdom.