PISCES: Patagonian Ice field Shrinkage impacts on Coastal and fjord EcosystemS

Ocean basins across a large proportion of the Earth's surface receive substantial freshwater and sediment input from glaciers and ice sheets. This freshwater input is increasing and will continue to do so as rising air and ocean temperatures enhance rates of ice melting and stimulate the collapse of floating glacier tongues. This is true of glaciers draining the Patagonian Ice Fields, the largest ice mass in the Southern hemisphere outside of Antarctica, almost all of which have thinned and retreated in recent decades. The physical impacts of Patagonian meltwater discharge on the oceans are becoming better studied, driven by a need to predict future sea level rise and future water supply for human settlements. However, the biological dimension of this freshwater export, is poorly understood. Large fjord systems act as receiving waters for glacial runoff and ice discharge in Patagonia, and together with marine waters, boast highly productive ecosystems and associated fisheries. The impact of glacial freshwater inputs to these ecosystems is likely to be important for several reasons. First, inputs of dilute glacial meltwater create a stable stratified water column for phytoplankton growth, but simultaneously may reduce nutrient supplies from vertical mixing. Second, glacial runoff and icebergs likely act as "fertilisers", being rich in highly bioavailable dissolved organic matter and other major nutrients, such as iron, phosphorus, nitrogen and silicon. Last, the high suspended particulate matter load of glacial runoff is likely to have a dual effect, adding further nutrients but creating light limiting conditions for plankton within inner fjord systems. These impacts on downstream ecosystems are likely to intensify as glacial freshwaer fluxes rise. Key unknowns at present are: 1) the magnitude, character and timing of glacial nutrient and sediment delivery to Patagonian fjord ecosystems; 2) how these inputs may alter in a warming world; and 3) the sensitivity of downstream ecosystem productivity and biodiversity to such inputs. PISCES will test the hypothesis that Patagonian Ice Field FW fluxes have a natural fertilisation impact upon downstream fjord and marine productivity, via a combination of field-based research and biogeochemical modelling. PISCES will generate the first ice-to-ocean dataset of riverine nutrient fluxes and biological response across a broad latitudinal transect in Patagonia. This will provide an important utility for policy makers managing freshwater supply, quality, marine ecosystems and fisheries in the region.

We anticipate that PISCES will make a major impact on the current state of science of ice-ocean biogeochemical and biological interaction. There are three main groups of beneficiaries and we will disseminate findings of the research project to these groups in the following ways

1) Scientific research communities: there will a clear interest in the outputs of this project across a wide range of scientific disciplines. The final project meeting to be held in Chile (Huinay) will be organized as a workshop on "Terrestrial nutrient cycling in the past/present and impacts on downstream ecosystems" and we will invite a range of key scientists in this field. After the second year of the project, we will host sessions on nutrient cycling and associated downstream impact in glaciated regions at large international conferences - e.g. AGU and Goldschmidt. This will provide an opportunity for members of the project to present project work to a large number of scientists, as well as inviting others to present/discuss their work. We also plan to set up exchange programmes between institutions. This will include exchange of undergraduate, masters and PhD students for short placements and summer fieldwork placements. In the long-term we will implement study abroad ties for undergraduate degree programmes. Similar schemes have already been successfully executed in Bristol with European, North American and antipodean institutions by Co-I Anesio.

2) Policy makers: there is currently a great scientific and societal need to predict how changes in glaciated regions will impact downstream hydrology and biology. The University of Bristol's Cabot Institute (http://www.bris.ac.uk/cabot/) was established to ensure societally relevant environmental research could be linked and embedded within the social sciences, with an aim of influencing stakeholders. All the Bristol members of this project are affiliated members of Cabot Institute. We will look to leverage use of the working links that the institute has in place with the Government Office for Science, the All Party Parliamentary Climate Change Group, the Environment Agency and the Met Office to ensure the policy implications of our work are well read. Additionally, members of this project are active contributors to the UK Polar Partnerships Committee (Tranter sits on the committee), APECS (Association of Polar Early Career Researchers, Hawkings) and the UK Polar Network (Hawkings), and SCAR (Scientific Committee on Antarctic Research; Wadham). These bodies also have connections to national and international policy makers.

3) General public: A key component of this project will be a branded website to advertise the project and communicate activates to stake holders. The website will be set up in Chile and will host information about PISCES, a live web blog, regular short video updates from the scientists, and links to partner institutions. The website will also host a "Portal to Patagonia", which will provide a media heavy background to this remote, diverse and unspoilt wilderness of outstanding natural beauty. It will be aimed at providing accessible information on the region for school children. We anticipate this will be a valuable teaching resource. A number of PISCES project members have experience with the production of short films for outreach purposes. We aim to make a short (5-10 minute) mini-documentary for 12-16 year olds with a preliminary title of "Understanding the secrets of Patagonia". We will also have regularly updated YouTube, Twitter and Facebook accounts working alongside the website.