Chronobiology of changing Arctic Sea Ecosystems (CHASE)

Rational: The CHASE programme will address the core objective of the NERC Changing Arctic Ocean Program by seeking to understand and predict how ecologically important species will respond to climate change. As the Arctic Ocean is warming, zooplankton such as copepods and krill are undergoing habitat range extensions polewards. This will result in exposure to new and more extreme day-length (photoperiodic) climates of the higher latitudes - known in many terrestrial species to have negative consequences on fitness. We will therefore aim to investigate the behaviour, physiology and genetic responses of copepods and krill to their natural and new photoperiodic environments. We will focus on the circadian biological clock, central in day-length measurement and in orchestrating key seasonal life-cycle events.

Approach: To understand large scale ecosystem responses to climate change we need to mechanistically understand small scale individual responses of key organisms driving marine ecosystems and their functional biodiversity. High variability between individuals is an indicator for high adaptive capacity of the population to changing conditions. Due to the ecological relevance of key species their individual variability can give an indication of future ecosystem shifts. Our approach focuses on the two Arctic key zooplankton groups Calanus finmarchicus / Calanus glacialis (calanoid copepod) and Thysanoessa inermis (krill). We will: 1) characterize the Arctic light climate (spectrum, irradiance) with latitude and season; 2) determine individual copepod and krill behavioural phenotypes with latitude and season; 3) investigate photoperiod as a diapause trigger in copepods; 4) determine the metabolic status of behavioural phenotypes (identified above); 5) provide seasonal characterization of gene expression with a focus on clock mechanisms and the influence of light and; 6) provide indicator genes characteristic for specific life-cycle events, metabolic processes and environmental conditions as well as genetic timekeeping; 7) investigate the effects of light and genetic clock mechanisms on seasonal timing and how the factors may synergistically interact with other environmental and physiological factors and; 8) incorporate these data into life-cycle models to provide a wider, predictive framework for this work.

We will combine a novel, but tested, approach to large scale behavioural screening of activity in copepods and krill with classical physiological investigations on fitness. Activity screening methodology adopted from Drosophila clock research will reveal diel behavioural cycles and rhythms as well as the change of these cycles/rhythms with different photoperiods. We will also use state-of-the-art genetic analyses to characterise the genetic traits of seasonal physiological changes and how light modulates circadian clock and clock related genes. Finally we will incorporate the behaviour, environment and physiological state into existing well-tested individual-based models and dynamic optimisation models to determine the predicted fitness costs of future Arctic climate change scenarios.

Application and benefits: The balanced functioning of the Arctic ecosystem is reliant on the success of key zooplankton primary consumers which influence all higher trophic levels, from fish to whales. CHASE aims to understand how such key organisms function in this extreme environment and will develop the predictive tools necessary to assess how climate change will impact their populations in the future. This will be achieved through a combined sampling/experimental/modelling programe, thereby informing future scientific directions, critical in helping manage areas which are rapidly becoming more accessible to increasing resource exploitation. The project is embedded within international Arctic science networks based in the UK, Norway and Germany and will have a legacy of cooperation beyond the lifetime of the funding.

Scientific community - CHASE aims to provide the scientific community with a new perspective of zooplankton population ecology which is of particular value to the Polar ecosystem modelling community already embedded in the NERCs changing Arctic Ocean programme. Our findings will be disseminated via high impact publications and presentations at major international meetings, principally Arctic Frontiers and Arctic Change Conferences. In addition there is increasing interest in clocks in non-model systems, particularly those under environmental extremes, to improve our understanding of the evolution of the circadian clock. We will therefore focus CHASE dissemination at various chronobiological meetings such as the UK Clock Club, Society of Biological Rhythms and the Chronobiology Gordon Research Conference.

Policy community - CHASE addresses many international Arctic research priorities as outlined in the EU PolarNEt and the 2015 ICARP III reports. These call for better understanding of Arctic ecosystems and specifically their responses and resilience to anthropogenic impacts whilst encouraging cross-cutting science and international collaboration. Our focal species are of high ecological importance to the North Atlantic and Arctic ecosystems and therefore of broad interest to Arctic fisheries biologists specifically our Nordic partners such as the Norwegian Institute of Marine Research. Further, the German Ministry of Education and Research for marine and Polar research MARE:N has identified "variability, acclimation and adaptability of key organisms to environmental change" as a target research area which should be supported by robust predictive models. Closer to home we will make available our findings to the UK Arctic Office thereby informing UK Arctic science towards future policy development, important at this time with the rapid expansion of Arctic open water for increased commercial exploitation. CHASE partners will be presenting our science during the Arctic Frontiers Tromso meetings which includes focused sessions addressing the opportunities and challenges to achieve viable economic growth with societal and environmental sustainability in the Arctic. We are also conscientious of our duty to IPCC on relevant issues.

General public - People are naturally fascinated by Polar Regions and it is therefore relatively easy to engage the public in Arctic science, particularly with images of polar bears. The challenge is to entertain and educate about more enigmatic subject matters such as zooplankton. However, our groups have been extremely successful in promoting our science, reaching a very wide audience via effective communications teams and understanding the needs of the media. A recent video abstract and press release centered on zooplankton behaviour dubbed "Arctic Werewolves" (for more information just google it) resulted in the top 1% of publicly cited papers for the high impact journal Current Biology. The increasing use of institutional websites linked to social media, especially twitter, has expanded our scientific 'reach', demonstrated by the 6.5K and 22K followers of the SAMS and BAS twitter feeds respectively. We will display our science in the SAMS Ocean Explorer Centre and provide educational material to local schools and nurseries in Argyll. We will also provide outreach material for the Glasgow Science Centre under the 'EnviroScience' theme to illustrate the effects of Arctic warming on ecosystems and link to a website at the University of Delaware focusing on using zooplankton for inquiry-based teaching and learning of biological concepts.

Finally CHASE is committed to training future Arctic scientists and our PDRAs will be encouraged to become part of the Association of Polar Early Career Scientists (APECS) to facilitate appropriate career development and networking and will be encouraged to take part in any SAMS/UHI transferrable skill development and science communication training programme.