Like most events this year, the final SponGES meeting took place virtually, on November 10-12 2020. The first day opened with a touching opening tribute to our coordinator Hans Tore Rapp, who sadly passed away early in March and is deeply missed by everyone. The meeting then unfolded through five plenary sessions covering the work done in the areas of habitat mapping, biodiversity, biogeographic patterns and connectivity, modelling and predicting changes, and ecosystem functions.
Furu Mienis from NIOZ gave an introduction about SponGES work in high-resolution mapping and in the characterisation of habitats in deep-sea sponge grounds ecosystems. She highlighted that such data are essential to understand how oceanographic and geological settings shape sponge grounds and the availability and distribution of linked ecosystem services. SponGES has also mapped the past distribution of deep-sea sponges, which is useful to understand how present-day sponge grounds may respond to putative drivers of change. Javier Cristobo from IEO and Ute Hentschel from Geomar covered the work on biodiversity, for both deep-sea sponges and their associated microbial communities, which has led to the description of many new species. This work has also clarified biogeographic trends and how deep-sea sponge grounds create habitat for other macrofauna. Thanks to samples from 20 research cruises across the Atlantic Ocean, the project has unveiled a previously unknown sponge-associated microbial diversity, and has shed light on the factors that influence such associations and their diversity. Ana Riesgo from NHM summarised the work done to describe patterns of evolution, distribution and connectivity of deep-sea sponges, which has led to the largest sponge genomic dataset produced to date. This is helping understand the origin of Demosponges, as well as their evolution and biology. Particle-tracking models, paired with studies on the reproduction, connectivity and genetic structure of deep-sea sponges are improving our understanding of how deep-sea sponge grounds are maintained. Mapping, biodiversity and connectivity are linked together by the integrative work summarised by Andrew Davies from URI, based on enhanced and/or re-developed modelling tools (some of which have been applied to sponge communities for the first time). Modelling has enabled the first quantitative understanding of sponges’ holobiont metabolism, and the identification of indicators to inform management. Finally, Manuel Maldonado from CSIC covered ecosystem functions, services and goods of deep-sea sponge grounds, focusing on their role in biogeochemical cycling, food webs and the metabolism of deep-sea ecosystems. This includes an in-depth understanding of deep-sea silicon, nitrogen and carbon cycling (with implications for benthic-pelagic coupling and global biogeochemical cycles) that also links back to the role of microbes in the biology and ecology of deep-sea sponges. In practice, this means being able to demonstrate what happens if deep-sea sponge grounds are degraded, with impacts on the provision of ecosystem services and ultimately on society (eg for the economies that rely on an healthy ocean). Everything is connected!
Day 2 started with Ana Colaço from IMAR and Ronald Osinga from WUR covering threats and impacts that may affect deep-sea sponge grounds, from individuals to ecosystem levels. Fishing may have long-lasting effects, but research shows that measures to protect both the economy and the habitats are possible. And what about other stressors? Here the picture gets more complicated. Climate change and sediment smothering may affect deep-sea sponges but these may also cope, to some extent and depending on co-occurring conditions. Trajectories of response and individual variability do not always allow for modelling and for accurate predictions. Shirley Pomponi from FAU, Paco Cardenas from UU, and Tiago Silva from UMINHO presented exciting results in the field of blue biotechnology, ranging from potential paths and applications of deep-sea sponge-derived bioactive compounds, to advancements in sponge cell lines and in the development of innovative biomaterials inspired by deep-sea sponges. Details on specific research lines of SponGES were also presented throughout the afternoon, mostly by the PhD students that will soon defend their theses. Empowering a new generation of deep-sea spongers is one of the most important legacies of the project. The new knowledge generated by the different project components (integrating field, lab and desktop research) was key to inform resource management and conservation analyses, presented by Merete Tandstad from FAO. The economic valuation of deep-sea sponge grounds proved challenging but focusing on Ecosystem Services helped overcome the issue. Capacity-building and policy round tables and workshops, together with the release of practical documents like factsheets and policy briefs (integrated in FAO’s portals, e.g. for Vulnerable Marine Ecosystems), have been instrumental in translating SponGES research into action. Martina Milanese from GAIA closed the day summarising our outreach in quantitative terms: more than 90 peer-reviewed publications (so far ) and over 20 technical documents, involvement in ca. 200 events (scientific, industry-focused, for the public and schools), in the news 100+ times, and more than 2M people reached in 4 years (without considering websites and social media).
Finally, Day 3 was dedicated to wrapping up and defining the way forward. The long yet engaging afternoon of today was dedicated to discussions on data integration and management, exploitation of the many results, and SponGES in the future. The meeting ended with another tribute to Hans Tore, celebrating together the achievements of a project he was so deeply devoted to.