The MEMO project gathers universities and research centres with the aim of gaining crossborder knowledge on the invasive marine species M. leidyi. This gelatinous zooplankton has been identified as a threat for the future of the 2 Seas coastal and marine areas. An increasing number of this specie could have important impacts on socio-economic activities in the area, such as fisheries, aquaculture or tourism. Thanks to an integrated crossborder approach, MEMO will contribute to a better understanding of the ecology of M. leidyi and of its possible impacts on marine ecosystems and economic activities.The final aim of the project is to share the results of this comprehensive study with a wide range of stakeholders including the general public, towards a shared integrated vision for the 2 Seas marine and coastal areas. By sharing knowledge and expertise, partners will demonstrate a proactive approach and give policy-makers the opportunity to anticipate ecological and economic problems related to this invasive specie, by means of scientifically underpinned mitigation measures. Expected Results: What are the key results of the project?Activity 1: data on predators and food sources for M.leidyi- 1 SOP and manual for the collection and preservation of gelatinous plankton, and a peer-reviewed paper- 1 SOP and manual for the identification (morphological and genetical) of M. leidyi, incl. a genetic tool to describe the distribution of this species- An integrated database comprising data on M. leidyi, other plankton and hydrological parameters- Distribution maps and a habitat model, to inform on the habitat preferences and potential distribution of M. leidyiActivity 2: ecological preferences of M. leidyi- Models and publications on reproduction of M. leidyi (fecundity, growth rate)- A published SOP for comb jelly maintenance and breeding- Models and publications on feeding rates (grazing impact, trophic competition, selectivity)- New insight in the trophic positioning of M. leidyi within the plankton food web- Publication of an integrated lndividual Based life cycle Model for M. leidyi in the 2 seas regionActivity 3: mathematical coupled with ecosystem models- Published integrated models for the spatial and temporal distribution and the potential expansion of M. leidyi- Thorough collaboration with different actors through the socio-economic questionnaire and meetings- Information produces on the potential impact of M. leidyi on industrial power plants, aquaculture and fisheries and tourism- Maps on vulnerable areas and delineation of areas where the impact of M. leidyi on marine resources is limited or can be reduced- Mitigation measures and cost calculations to counteract the possible threat of M. leidyi and other gelatinous plankton on different sectors in the 2 seas region- Communication website, workshops and newslettersAre all partners and territories benefitting from the results?The scientific community will directly benefit from MEMO, through sharing of skills, knowledge, human resources and laboratory devices.The SOPs for sampling and identifying M. leidyi will constitute uniform tools and help in developing and maintaining monitoring programmes.The governmental and maritime business actors will be able to use the results of this study in their daily practice, selecting which mitigation measures are best to prevent the risk of a potential invasion of M. leidyi.The final beneficiaries will be the wider public who benefit from MEMO. The project allows scientists, authorities and stakeholders to adapt the developed tools in support of clear communication with the public. An accurate definition of gelatinous zooplankton distribution, dispersal and development is crucial to areas where recreational activities are taking place. The socio-economic survey planned in the project will allow assessment of humans experience concerning the presence of comb jellies and (stinging) jellyfish in bathing or fishing waters. MEMO will help estimate potential risks on fisheries, industrial plants, tourism, marine protected areas, and the calculation of the prevention costs.What are the effects / outcomes for the territories involved?Distribution maps and a habitat model will be developed, that will inform different stakeholders on the habitat preferences and potential distribution of M. leidyi. In this way, the potential impact of M. leidyi on industrial power plants, aquaculture and fisheries and tourism will be studied. Maps of vulnerable areas (e.g. with high risk on eggs and larvae of fish and shellfish) will be made and areas where the impact of M. leidyi on marine resources is limited or can be reduced will be defined. Mitigation measures will be sought and cost calculations will be made to counteract the possible threat of M. leidyi and other gelatinous plankton on different sectors in the 2 seas area. Information on the conditions for the survival of M. leidyi enables an ecosystem-based management strategy for fisheries and the preservation of marine productivity and biodiversity.The different stakeholders will be able to use the results of this study in their daily practice, and the government can choose which mitigation measures are best implemented to prevent the risk of a potential invasion of M. leidyi. Each government can use the results of the case-study that is best suited for their country e.g. Gravelines powerstation in France.