Marine Alien Species at Pserimos Island (Greece): census with the help of citizen scientists

Abstract

Observations of citizen scientists have become an indispensable source in the collection of biodiversity data worldwide. In Greece, the findings of these citizen scientists, in collaboration with the Hellenic Network on Aquatic Invasive Species (ELNAIS), have resulted in compiling diverse information on marine alien species. Since 2004, the Liamis Dive Centre has recorded visual data on 12 marine alien species around Pserimos Island (Dodekanisa, Greece), thus enabling us to sequence their progression and displacement amongst other vital information. The real number of biological invasions is likely to be higher than reported here because citizen scientists do not have the scientific skills required for species identification and also due to financial constraints. Nevertheless, the high number of observers to a certain extent compensates the lack of taxonomic expertise.

The Indo-Pacific brachyuran Charybdis (Gonioinfradens) paucidentatus(A. Milne-Edwards, 1861) (Brachyura, Portunidae) in the Cyclades, Aegean Sea

“…The expansion of the C. (G.) paucidentatus population has already been documented since 2013 north to Rhodes, on the small island of Pserimos, near Kalymnos Island (southeastern Aegean Sea), where it is considered established (Zenetos et al, 2017). This alien species is herein reported for the first time from Santorini Island, southcentral Aegean Sea, where it appears to be established.…”

An assessment of regulation, education practices and socio-economic perceptions of non-native aquatic species in the Balkans

“…Based on the results of this survey, countries with a coastline seem more focused on marine than freshwater environments. Citizen science initiatives on NNS are well developed in marine ecosystems in Greece (Perdikaris et al 2017, Zenetos 2017, Giovos et al 2019 and have begun in Albania (Tanduo et al 2020) and Turkey (Huseyinoglu et al 2021 The definition of NNS of Montenegro is regulated by policy acts and corresponds to the NNS definition stipulated in the policy acts of Croatia. However, in other Balkan countries, as in the EU Member States, there is no consistent definition of NNS (Boon et al 2020).…”

Abundance and population characteristics of the invasive sea urchin Diadema setosum (Leske, 1778) in the south Aegean Sea (eastern Mediterranean)

“…The few existing data from temperate populations are limited to the reproductive biology of the species [8][9][10][11], their grazing [12] and the bioerosive pressure they inflict in rocky biogenic habitats [13], and to the cytotoxicity of its bioactive compounds [14]. Focusing on the Mediterranean population, existing data refer exclusively to its occurrence [2,[15][16][17][18][19][20][21][22][23][24][25][26], whereas only a single study examined the genetic profile of the species and suggests further spread of D. setosum in the near future through larval transport [5].…”