| Summary: | Based on dietary data, this study aims, to perceive the influence of the top predators of marine megafauna on the trophic interactions between predator-prey and predator-predator among the ecosystems belonging to the oceanographical area of the Azores and the remaining marine areas of Europe. For this, it was necessary to categorize the species in different functional groups according to their specific taxonomy and to acquire knowledge about their diet and the relationships established with other levels of the food chain. Meta-analysis of stomach data converted into weight percent (%W) was the chosen mechanism to interpret and represent trophic interactions in a realistic way. In particular, the meta-analysis was applied to a database developed by the SUMMER (Sustainable management of mesopelagic resources) project, ongoing since 2019, which compiles samples from 145 different sources and stomach contents of 65 species and 10,719 individuals (13% of mesopelagic fish and 87% of predators). On the other hand, it was necessary to expand this collection of samples with bibliographic research to verify the compiled data and add new records related to the Azores archipelago and the rest of the Northeast Atlantic and the Mediterranean Sea. Estimates of the contribution of different prey to the diet of each species and/or groups of predators were made to allow comparing the diet composition of different consumers. The calculations were performed using a weighted average of the prey bulk data and based on the sampling areas of the respective studies. The results revealed a greater dietary similarity between teutophagous, tunas, dolphins and deep-sea sharks. Mesopelagic cephalopods predominated in the diet of half of the predators (in 17 of the 34 species analyzed) and had a greater contribution to the dissimilarities between the diets of different groups of predators (namely, between toothed whales teutophagous and tunas, corresponding to ± 24.4% and between whales teutophagous and deep-sea sharks, corresponding to ± ...
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