Online tool to integrate evidence-based knowledge into cumulative effects assessments: Linking human pressures to multiple nature assets

Abstract Intensification and diversification of human-induced pressures in marine ecosystems have raised concerns over several sustainability-diminishing consequences, such as hypoxia and overexploitation of resources. We present the PlanWise4Blue tool (PW4B), which assesses the cumulative effects of multiple pressures on nature assets. In order to express the sensitivity of different nature assets to a plethora of pressure combinations, a meta-analysis based on published literature and available datasets was performed to calculate a set of standardized effect sizes. These calculations relied mostly on experimental or observational evidence; expert knowledge was used to estimate the impact coefficients only in the absence of impact data. Spatial modelling techniques (machine learning) were used to model the probability of occurrence and abundances of different nature assets in lattice grids with a cell size of 1 km2. Users can use the portal to estimate impacted areas and changes to natural assets caused by any combination of anthropogenic pressure. The PW4B tool can be used to predict individual and synergistic effects — both current and future — of a wide range of human activities and can be used regardless of scientific background. The tool was tested in the Baltic Sea region in coordination with the process of the Estonian Maritime Spatial Planning. This test evaluated the combined effects of human activity such as fisheries, aquaculture, wind energy, mining and maritime transport sectors on nature assets such as selected seaweed, invertebrate, fish habitats as well as bird and mammal species. The analyses showed that current Estonian maritime spatial planning will result in a moderate loss of some nature assets and a significant gain of benthic suspension feeders, although predicted losses in wind park areas can be mitigated if novel aquaculture activities such as mussel or macroalgal farming are established This test demonstrates how the PW4B tool can be used by planners to minimize adverse environmental effects, to suggest effective mitigation strategy, and to attain sustainable planning solutions.