Never before in recorded human history have there been as many extreme climatic events as in the past decade, with anthropogenic climate change the major contributor to this trend. Droughts, floods, storms, and heatwaves are all linked through Earth's climate systems and can have significant ecological and socio-economic impacts on land and in the oceans. Despite growing appreciation of the importance of extreme climatic events in determining ecosystem structure the vast majority of knowledge stems from terrestrial research, even though marine ecosystems play a central role culturally, socially and economically in the lives of most people. Marine ecosystems provide a myriad of ecological goods and services, including nutrient cycling, food and other resources, biogenic coastal defence and climate regulation, all of which have substantial socioeconomic value. Coral reefs, seagrass meadows and kelp forests are particularly valuable in terms of capital generated from recreation, fishing activities, coastal defence and biodiversity, and contribute trillions of pounds to the global economy each year. In the UK alone, the estimated direct economic value of marine biodiversity exceeds £20 billion per year. In marine environmental research, much attention has been given to ocean acidification and, more recently, plastic pollution, yet there is a strong argument to suggest that extreme warming events (i.e. 'marine heatwaves' (MHWs)) pose an even greater risk to ecosystems. In the past decade alone, MHWs have devastated entire ecosystems and severely affected fisheries, aquaculture, food webs and carbon cycling. The frequency and duration of MHWs has increased significantly in recent decades and is predicted to increase throughout the 21st Century, as a consequence of anthropogenic climate change. Despite the unequivocal importance of MHWs in structuring ecosystems, our current understanding of their impacts remains poor. Knowledge of responses to MHWs stems from only a few events, such as the 1998 El Niño episode, the Mediterranean MHW of 2003 and the 2011 warming event off Western Australia. The 2011 MHW off Western Australia, for example, resulted in major shifts in benthic ecosystem structure in a tropical-temperate transition zone, by causing widespread mortality of cool-water habitat forming species. This project will address critical knowledge gaps in marine climate change ecology. It will synthesise existing information on ecological responses to MHWs and use a novel analytical approach to conduct a global-scale analysis of their impacts. The project will also carry out a range of experiments and surveys to examine how key organisms and processes are affected by MHWs with differing physical attributes. Finally, predictions of future patterns and impacts of MHWs will be made, based on physical and ecological modelling techniques. This project will significantly advance understanding of the impacts of extreme climatic events in the global ocean and will be of direct relevant to climate change mitigation and adaptation, as society must safeguard valuable coastal marine ecosystems against increased climatic stress in the coming decades. Aside from significant academic impact, the research project will have considerable wider societal impact. The findings will be translated and fed into policy at both the national (e.g. MCCIP, CEFAS) and international (e.g. IPCC, ICES) level. Research on commercially-important species and habitats will be directly relevant for the aquaculture and fishing industries. Work on climate change-carbon cycle feedbacks will be of strategic significance to those working on Blue Carbon and climate change mitigation (e.g. IUCN, Blue Carbon Initiative). Throughout the project the importance of coastal marine ecosystems and threats posed by climate change stressors will be communicated widely to academics, industry, policy-makers and the wider public through a variety of channels.

Abstracts are not currently available in GtR for all funded research. This is normally because the abstract was not required at the time of proposal submission, but may be because it included sensitive information such as personal details.

The "smell of the seaside" is actually caused by a gaseous compound called dimethyl sulfide (DMS) that is produced by microbes. This gas is important because it is a very abundant organic sulfur compound which is released to the air from the marine environment. Globally, approximately 300 million tons of DMS per annum is produced, mainly by bacteria. Also, chemical products arising from DMS oxidation help form clouds over the oceans, to an extent that affects the sunlight reaching the Earth's surface, with effects on climate. In turn, these products are delivered back to Earth as rain, representing a key component of the global sulfur cycle. Interestingly, DMS is a potent chemo-attractant for many organisms including seabirds, crustaceans and marine mammals that all move towards DMS because they associate DMS with food. Currently it is widely accepted that DMS is mainly produced as a result of microbes degrading the osmolyte dimethylsulfoniopropionate (DMSP), which is produced by phytoplankton in the oceans, by seaweeds and by a few salt-tolerant plants. Our preliminary work and that of Ron Kiene, has prompted us to question whether it is solely these processes that produce DMS. In our preliminary data we have: 1. Found a microbial pathway, the methanethiol-dependent DMS production (Mdd) pathway, that produces DMS but which does not involve DMSP. 2. Shown how the bacterium "Pseudomonas deceptionensis" makes DMS via a gene called mddA. 3. Shown that this gene is found in a wide range of bacteria such as Bradyrhizobium japonicum, a nitrogen-fixing symbiont of soybeans, Mycobacterium tuberculosis, the causative agent of tuberculosis and some cyanobacteria. 4. Shown that the Mdd pathway is active in both salty and freshwater sediments and that the mddA gene is abundant in bacteria living in marine sediments. 5. Shown that other bacteria have other undiscovered ways of making DMS from methanethiol. We wish to investigate how important this novel DMS production pathway is for the global production of this climate changing gas. To answer this question, we will sample various marine and freshwater environments and investigate how active the Mdd pathway is in these environments and how this novel pathway for the production of DMS is regulated. We already know that this Mdd pathway is probably active in most of our sample sites, which include mud from a saltmarsh, a freshwater lake, a peat bog and seawater. It is equally important to know which microbes are responsible for the process (mediated by Mdd) and why they produce DMS. We will use a powerful suite of microbial ecology techniques, combined with genetic tools to identify the microbes and the key genes involved in producing DMS via this new Mdd pathway. We will identify: a) the microbes living in both the oxic and anoxic mud samples and in seawater; b) how these microbial communities change when we enrich for increased DMS production via the Mdd pathway and c) which forms of the mddA gene (and the enzyme encoded by this gene) are responsible for high DMS production in these varied environments. To understand how and why bacteria in the environment are Mdd active, we will study in detail a few model bacteria, some of which have been isolated from our sample sites. This will involve identifying and mutating the genes encoding the Mdd pathway to ascertain why they use it. This will be done with bacteria that have a specific gene "mddA", but, also on those that do not, which will allow us to identify new mdd genes. Given the environmental consequences of the climate-active gas DMS, it is important to know which types of microbes affect its production and which of the various potential pathways are involved. This will help us in the future to model how changes in the environment impact on the balance of these climate processes.

Abstracts are not currently available in GtR for all funded research. This is normally because the abstract was not required at the time of proposal submission, but may be because it included sensitive information such as personal details.

The Leeds Condensed Matter Physics Group have been regular users of synchrotron radiation at the NSLS now for over six years, where the unique element-specific sensitivity to magnetism of polarized soft x-rays has made great contributions to our research in studying disorder, anisotropy and hysteresis in a variety of nanomagnetic systems. Here we request travel funding to allow us to pursue here two main avenues of research in our new two year user programme at that facility. The first is soft x-ray magnetic scattering from arrays of nanomagnets, fabricated at the Brookhaven Center for Functional Nanomaterials, which exhibit frustrated geometries: whilst the underlying physical structure is periodic, the magnetic structure will display only short range order due to the frustration. Off-specular magnetic scattering will allow us to characterize this disorder as a function of sample array geometry, magnetic field, and temperature, yielding complementary information to real space imaging techniques. The second area is in the study of magnetic nanoclusters, formed by gas-phase aggregation and deposited as part of a magnetic multilayer stack such as a tunnel junction. We have the capability to produce very narrow and well-controlled size distributions, so size dependences. Here we will study spin-orbit moment ratios and chemical composition, such as oxidation from surrounding tunnel barrier material, using XMCD spectroscopy. Unlike similar european facilities, synchrotron beamtime at the NSLS does not come with money to support travel to the facility. The experiments form part of our ongoing and highly successful joint programme on magnetic scattering between Leeds and ISIS. The grant request is for travel and subsistence funds only to allow a team of three people to travel to Brookhaven for five weeklong periods in order to operate the experiment 24 hours a day, as well as carry out sample fabrication at the CFN and present our results at conferences.