Ki uta ki tai: mātāpono me te pūtaiao, ngā korero whakamahuki ma te kaitiaki - From mountains to the sea: values and science for an informed kaitiaki / guardian

Ki uta ki tai is a te ao Māori concept that more holistically encompasses and appreciates the interconnectedness of all parts of the system. The concept includes, but is not limited to, the connectivity between land, freshwater, estuaries, oceans, and climate. Two of New Zealand's National Science Challenges (Sustainable Seas, Our Land & Water), in partnership with the Ministry for the Environment, embarked upon a combined programme of work known as the 'Ki uta ki tai' project. It aimed to achieve impact by bringing knowledge streams together through shared visions, values, and processes to inform catchment-based solutions that would ultimately improve the mauri of catchments and estuaries. The project sought to make progress towards integrated estuarine ecosystem management reflecting Ki uta ki tai concepts by: 1. elucidating pathways for meaningful and culturally appropriate partnerships with iwi, hapū, and whānau seeking to improve freshwater and estuarine management integration for better environmental and socio-cultural outcomes. 2. overcoming technical challenges on the integration of freshwater/catchment modelling with estuarine ecological health assessment. Working with mana whenua requires a willingness to engage in authentic relationships, open communication and face-to-face meetings to discuss the concerns, aspirations and priorities of localised species and spaces. Joint fieldwork and excursions to sites of interest were extremely informative and critical to the success of our project. Engaging at the local level was found to be the most appropriate and productive approach. We developed metrics of exposure of individual estuarine sites to freshwater contaminants by (i) using rating curves to generate time-series freshwater load data, and (ii) spatially distributing those loads to sites where we had estuarine health data. We then explored drivers of change in estuarine health metrics, including exposures to suspended sediments, total nitrogen, total phosphorus, and E. coli (from freshwater) along with oceanic and climate related drivers such as sea surface temperatures and El Niño strength.