Copepods dominate marine zooplankton in abundance and play key roles in pelagic food webs. These small crustaceans show high taxonomic and functional diversity. Although there has been considerable research on their taxonomy, only a few studies have focused on their functional traits. In this study, we analyzed the functional traits of 95 copepod species, considering their body size, trophic regime, feeding behavior, and spawning strategy. Based on samples collected during two surveys (autumn 2020 and summer 2021) located in the coastal waters of three gulfs (Gaeta, Naples, and Salerno) in the highly populated Campania region (the central Tyrrhenian Sea, NW Mediterranean), we identified nine functional groups of copepods with different characteristics. The group that comprised herbivorous copepods with feeding currents and a broadcast strategy was the most abundant in both seasons and all gulfs. This group was dominated by Acartia clausi, Centropages typicus, Temora stylifera, and the Paracalanus parvus complex. The other functional groups showed differences in their temporal and spatial distribution. Our study reports the functional diversity of copepods along the Campania coast, thus contributing to advancing our knowledge of the planktonic trophic structure in a region of considerable importance due to its marine resources and services.

Among non-native copepods, the calanoid Pseudodiaptomus marinus Sato, 1913 is the species probably spreading at the fastest pace in European and neighbouring waters since its first record in the Adriatic Sea in 2007. In this contribution, we provide an update on the distribution of P. marinus in the Mediterranean and Black Seas, along the Atlantic coasts of Europe, in the English Channel and in the southern North Sea. Starting from a previous distribution overview, we include here original and recently (2019–2023) published data to show the novel introduction of this species in different geographical areas, and its secondary spreading in already colonised regions. The picture drawn in this work confirms the strong ability of P. marinus to settle in environments characterised by extremely diverse abiotic conditions, and to take advantage of different vectors of introduction. The data presented allow speculations on realistic future introductions of P. marinus and on the potential extension of its distribution range.

The global biodiversity crisis brings significant environmental and social impacts, necessitating innovative approaches to achieve the Sustainable Development Goals. This is particularly relevant for coastal peripheries that are rich in both natural and cultural capital. The Reknotting Marine Biodiversity project adopted a trans-disciplinary approach to integrate participatory science and education, involving local communities and researchers in biodiversity monitoring using environmental DNA metabarcoding along the coast of Marina di Camerota, Southern Italy. This approach compared Posidonia oceanica habitats with areas subject to anthropogenic pressures. Results show a greater diversity of pelagic fish and benthic organisms in the presence of P. oceanica, nine species that can potentially cause Harmful Algal Blooms (HABs), and eight species responsible for non-toxic algal blooms in less pristine areas. This study highlights the value of coastal habitats and the strategic value of citizen science in raising ecological awareness, proposing a replicable model for local marine observatories jointly managed by scientists and citizens.