The challenge: The study of life's adaptation to extreme environments challenges our fundamental understanding of biological systems from molecular to whole organism levels. Proteins are key building blocks for all life on Earth with functions that are uniquely dependent on their 3-D folded state. Whilst much is known about constraints on how proteins operate at high temperatures, little knowledge exists about how biology operates at all scales of life in sub-zero conditions where proteins are less stable and oxidative damage is high. Almost 90% of the habitable biosphere is permanently below 5°C (i.e. deep sea and polar regions). Hence, we do not understand how a large proportion of global biodiversity functions at such low temperatures: A critical knowledge gap given the current climate crisis and impeding large-scale loss of the planet's colder regions and their endemic biodiversity. Aims and interdisciplinarity: Cellular proteins are adapted to function in highly crowded solutions of macromolecules, which affect protein folding, diffusion, and interactions. Temperature plays a critical role in these processes. However, there are currently no tools available that image live cells at very low temperatures. We will use the most advanced methods to adapt current state-of-the-art microscopy, and for the first time, develop fully automated microscope technology optimised for the high-resolution optical imaging of live animal cells near 0°C. This will enable us to observe the behaviour of proteins in situ and gain a deeper understanding of the behaviour of proteins near 0°C within the complex environment of the living cell. The system will be used for studies of Antarctic fish cell cultures at 0°C, our cold-adapted model organism. In particular, we will study temperature effects and cell viscosity in the context of protein folding within the cell, using a fast-folding protein, Venus, introduced into the Antarctic fish cells at 0°C and use single molecule translation imaging, developed by us, to compare the time for protein folding with temperate systems. This highly interdisciplinary project is at the very intersection of biology, physics and chemistry and involves collaboration between world-leading researchers in cutting-edge microscopy, molecular cell biology, and polar marine biology.

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.

Mixing of the ocean around Antarctica is a key process that exerts influences over large scales and in multiple ways. By redistributing heat in the ocean, it exerts strong influences on the Antarctic Ice Sheet, with implications for sea level rise globally. Similarly, the redistribution of ocean heat affects the production of sea ice in winter and its melt in summer, with consequences for climate. Mixing also affects the distribution of nutrients in the ocean, with direct impacts on the marine ecosystem and biodiversity, and with impacts on fisheries. It was long thought that mixing of the seas close to Antarctica was predominantly caused by winds, tides, and the loss of heat from the ocean especially in winter. However, we recently discovered that when glaciers calve in Antarctica, they can trigger underwater tsunamis. These are large (multi-meter) waves that move rapidly away from the coastline, and when they break they cause sudden bursts of very intense mixing. Simple calculations indicated that the net impact of these underwater tsunamis could be as strong as winds, and much more important than tides, in driving mixing. It was also argued that they are likely to be relevant everywhere that glaciers calve into the sea, including Greenland and across the Arctic. As our ocean and atmosphere continue to heat up, it is very possible that glacier calving will become more frequent and intensify, increasing further the impact of underwater tsunamis on large-scale climate, the cryosphere, and ecosystems. This is an exciting new avenue of scientific investigation, and many key questions remain unanswered. We need to know how widespread and frequent the generation of underwater tsunamis is, how far they travel from the coastline before breaking, and how variable this is. We need to measure what impacts the extra mixing has on ocean temperature and nutrient concentrations, and to determine what this means for the cryosphere and ocean productivity. There is a pressing need to include the effects of underwater tsunamis in the computer models that are used for projecting future ocean climate and ecosystem conditions, and to determine the feedbacks between climate change and the generation of more underwater tsunamis. To answer these questions, our project will deploy innovative techniques for measuring the ocean and ice in close proximity to a calving glacier, including robotic underwater vehicles and remotely-piloted aircraft, and cutting-edge deep-learning techniques applied to satellite data. We will use advanced computer simulations to fully understand the causal mechanisms responsible for the creation and spread of the underwater tsunamis, and their impacts on ocean climate and marine productivity. We will make our developments in computer simulation available to the whole community of users, for widespread uptake and future use. This project will have significant benefits for academics seeking to predict the future of Antarctica and its impacts on the rest of the world, for Governments and intergovernmental agencies seeking to understand how best to respond to climate change, and for the curious general public wanting to learn more about the extremes of the planet and why they matter. The fieldwork will be especially photo- and video-genic, and will lead to outstanding outreach and impact opportunities, and we will work with media agencies seeking to tell compelling stories about the extremes of the Earth.

The ocean holds fifty times as much carbon as is in the atmosphere. Biological processes contribute to storing carbon in the ocean on climate-relevant timescales (hundreds to thousands of years). Marine phytoplankton (drifting microscopic plants) use sunlight and carbon dioxide in the upper ocean to form their bodies which are rich in carbon. When phytoplankton die they might clump together and sink into the ocean interior, or they could be eaten by zooplankton (tiny animals) which produce fecal pellets that can sink rapidly. Once this organic carbon is deeper in the water, bacteria might colonise the particles and break them down, or they could be broken apart by zooplankton feeding on them. These processes all act to reduce the amount of organic carbon reaching the deep ocean, however the deeper it goes the longer it will remain out of contact with the atmosphere. This "biological carbon pump" helps to regulate our climate, and without biology in the ocean it has been shown that atmospheric carbon dioxide levels could be nearly double what they are today. Earth system models have differing, but all fairly simple, representations of the biological carbon pump due to a lack of understanding of how the processes contributing to particle formation and respiration function. The suite of models that contribute to the Intergovernmental Panel on Climate Change reports do not agree on the magnitude or direction of change for ocean carbon storage under future climate scenarios. This means we have low confidence for our future projections of ocean carbon storage, which is further impeded by a growing discrepancy between models and observations. In this project we will examine how much carbon has been respired during the transit from the upper ocean, and in what ways. We will measure the important processes of particle fragmentation and aggregation, microbial respiration, and zooplankton vertical migration and respiration. We will do this using a process cruise and autonomous underwater vehicles. We seek to answer the question: How is organic matter transformed and respired by biotic interactions in the mesopelagic, how does that vary with depth, location and season, and what are the consequences for ocean carbon storage? The ultimate goal is to generate new detailed understanding of important processes that influence the rate and depth of interior respiration which we will scale up to provide the globally-resolved information needed to develop the next generation of biogeochemical models.

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.