The freshwater Fish Invasiveness Screening Kit (FISK) has been applied in 35 risk assessment areas in 45 countries across the six inhabited continents (11 applications using FISK v1; 25 using FISK v2). The present study aimed: to assess the breadth of FISK applications and the confidence (certainty) levels associated with the decision-support tool’s 49 questions and its ability to distinguish between taxa of low-to-medium and high risk of becoming invasive, and thus provide climate-specific, generalised, calibrated thresholds for risk level categorisation; and to identify the most potentially invasive freshwater fish species on a global level. The 1973 risk assessments were carried out by 70 + experts on 372 taxa (47 of the 51 species listed as invasive in the Global Invasive Species Database www.iucngisd.org/gisd/ ), which in decreasing order of importance belonged to the taxonomic Orders Cypriniformes, Perciformes, Siluriformes, Characiformes, Salmoniformes, Cyprinodontiformes, with the remaining ≈ 8% of taxa distributed across an additional 13 orders. The most widely-screened species (in decreasing importance) were: grass carp Ctenopharyngodon idella, common carp Cyprinus carpio, rainbow trout Oncorhynchus mykiss, silver carp Hypophthalmichthys molitrix and topmouth gudgeon Pseudorasbora parva. Nine ‘globally’ high risk species were identified: common carp, black bullhead Ameiurus melas, round goby Neogobius melanostomus, Chinese (Amur) sleeper Perccottus glenii, brown bullhead Ameiurus nebulosus, eastern mosquitofish Gambusia holbrooki, largemouth (black) bass Micropterus salmoides, pumpkinseed Lepomis gibbosus and pikeperch Sander lucioperca. The relevance of this global review to policy, legislation, and risk assessment and management procedures is discussed.

Invasive alien species (IAS) are a significant and growing problem worldwide. In Europe, some aspects of IAS have been\ud addressed through existing legal instruments, but these are far from sufficient to tackle the problem comprehensively. The\ud FINS II Conference considered the relevance of Top 20 IAS issues (Top 10 threats and opportunities) for Europe determined\ud at the 1st Freshwater Invasiveness – Networking for Strategy (FINS I) conference held in Ireland in 2013. Using a similar\ud format of sequential group voting, threats from FINS I (lack of funding, of awareness and education; poor communication)\ud and several new threats (lack of lead agencies, of standardized management and of common approach; insufficient monitoring\ud and management on private property) were identified by 80 academics, applied scientists, policy makers and stakeholders\ud from 14 EU and three non-EU countries (including 10 invited speakers) during four workshop break-out sessions (legislation\ud remit in both EU/non-EU countries; best management and biosecurity practice for control; data management and early warning;\ud pathways of introductions and citizen science). Identified opportunities include improved cooperation and communication,\ud education and leadership to enhance public awareness and stakeholder participation, systems establishment for early detection,\ud rapid response, monitoring and management of IAS using standardised methods of data collection, storage and usage. The\ud sets of threats and opportunities identified underline the importance of international cooperation on IAS issues in\ud communication, education and funding as priorities, as well as in standardization of legislation, control methods and best\ud practise of research

In this paper we supplement Greece’s recent annotated inventory of freshwater fishes per hydrographic basin with recent distributional data and taxa alteration information, based on field sampling and a literature review up to September 2011. We report on newly documented distributional records of 31 fish species plus one unidentified taxon, within 35 hydrographic river basin units in Greece. These new records include 14 native fish species, seven alien and 12 translocated. Translocated taxa are distinguished from aliens, in order to report species non-indigenous to a basin but native within the same ecoregion. Twelve hydrographic basin units are newly added to the roster of ichthyologically explored river basins following a previous basin-scale inventory method (the total is now 117). This review increases the number of Greece’s freshwater fish taxa to 167, since four new species are added to the list (Carassius langsdorfii, Neogobius fluviatilis, Telestes alfiensis, Millerigobius macrocephalus) and two are deleted (Salmo dentex, Barbus rebeli) due to taxonomic changes. Taxonomic changes will probably continue to alter the national list since phylogenetic research is ongoing on several taxa in many parts of the country