Physical and biological dynamic coastal processes and their role in coastal recovery (BLUE-coast)

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The BLUE-coast consortium addresses NERC highlight topic B, Coastal morphology: coastal sediment budgets and their role in coastal recovery. This project will adopt a holistic and multidisciplinary approach, combining the expertise of biologists, coastal engineers, geologists, geomorphologists and oceanographers with complementary experimental (field and laboratory) and numerical skills, to understand what processes control the coastal system dynamics and answer the relevant scientific questions. BLUE-coast will explicitly address uncertainties in the prediction of medium-term (years) and long -term (decadal and longer) regional sediment budgets and better understand morphological change and how the coast recovers after sequences of events, such as storms by: (i) improving representation of both transportable and source material within the coastal zone within models; (ii) establishing how transportable material is mediated by the ecological system using exemplar habitats representative of the UK coastal zone; (iii) assessing sensitivities of this mixed-sediment physical and biological system to possible changes in external forcing, including the combined impact of multiple variables and sequences of events, with the goal of understanding the internal dynamics of the system (e.g. nonlinearities, critical thresholds, tipping points, precursors and antecedent conditions) in parallel with assessments of behavioural uncertainties, and (iv) reduce uncertainties in medium to long -term prediction of regional sediment budgets and morphological change.Project Overview: the scope of the Highlight Topic sets a requirement for quantitative knowledge on both physical and biological dynamic coastal processes in order to improve hydrodynamic model predictions of regional sediment budgets and morphological change. To deliver an integrated, holistic and cost effective response, our main activities will combine (i) a detailed study of representative shelf sea landscapes that spans the full variety of organism-sediment conditions typically observed in temperate coasts, with (ii) in situ validation studies of key processes, and (iii) manipulative laboratory and field experiments aimed at unambiguously identifying causal relationships and establishing generality, and (iv) integration of new understanding of controls and effects on coastal morphodynamics at regional scales and under environmental forcing. By undertaking a substantial element of in situ observation and process studies, we will directly quantify the effect of antecedent conditions on coastal erosion and recovery, the effect of biota on mediating sediment fluxes and pathways and the effect of event sequencing on coastal erosion and recovery, across a range of geographically significant sediment habitats. These data will act as calibration and validation datasets for existing and innovative numerical models that will be able to simulate the coastal morphological consequences of key biological and physical drivers, alone and in combination. We will gain mechanistic understanding and achieve generality by performing carefully controlled experiments, generating different flow regimes using flumes, tracking changes during natural events using state-of-the-art field measurement technology and, in the laboratory, using intact sediments and sediment communities exposed to anticipated future conditions (warming, ocean acidification, nutrient loading). As it is not feasible to quantify all the relevant morphodynamic processes at high spatial resolution across the entire UK coast, our approach is to address the principal objectives through 4 interdisciplinary workpackages that follow a logical progression of scientific themes.