Risk screening of non‐native freshwater fishes in Croatia and Slovenia using the Fish Invasiveness Screening Kit

Abstract

The Fish Invasiveness Screening Kit (FISK) version 2 was used to assess the invasiveness potential of 40 introduced and translocated freshwater fish species to Croatia and Slovenia. Based on a priori classification of invasiveness, receiver operating characteristic analysis of FISK scores from two independent assessors resulted in a statistically significant calibration threshold of 11.75. This indicated that FISK was able to discriminate reliably between non‐native species likely to pose a high risk of being invasive and those likely to pose a medium or low risk of invasiveness. Seven species were categorised as ‘medium risk’ and the other 33 as ‘high risk’, whereas no species was categorised as ‘low risk’. The two highest scoring species were European catfish Silurus glanis and North African catfish Clarias gariepinus. Mean scores for all species classified a priori as invasive were ranked as ‘high risk’ sensu lato and fell into the ‘moderately high risk’ subcategory. FISK proved to be a valid tool for assessing the risks posed by non‐native fishes in Croatia and Slovenia. For this reason, it can be adopted as a reliable tool for the prevention of new translocations or introductions of potentially invasive species in the risk assessment area, as well as to assist in decisions regarding future management (i.e. monitoring, control and eradication) and conservation strategies.

Comparison of Taxon‐Specific and Taxon‐Generic Risk Screening Tools to Identify Potentially Invasive Non‐native Fishes in the River Neretva Catchment (Bosnia and Herzegovina and Croatia)

“…Overall, FISK and AS‐ISK provided virtually identical threshold values to distinguish species likely to pose a high risk of being invasive from those likely to be of low‐to‐medium risk in the River Neretva catchment. The mean calibrated FISK threshold score for the Neretva of 10.25 is close to that of 9.5 for the southern Balkan countries of Serbia, Montenegro, FYROM and Bulgaria (Simonović et al , ) and of that of 11.75 for the northern Balkan countries of Croatia and Slovenia (Piria et al , ). The similarity in these threshold scores suggests that a relatively low threshold between low‐to‐medium and high‐risk species is characteristic for the Balkans Peninsula, which has been subjected to an elevated number of translocations.…”

“…Other species of ‘high risk’ in the present study, namely, A. melas , A. nebulosus , Cy. carpio and Pseudorasbora parva (Temminck and Schlegel, 1846), have been widely introduced worldwide and ranked as ‘very‐high risk’ for other parts of the Mediterranean Region (Almeida et al , ; Simonović et al , ; Tarkan et al , ; Piria et al , ). Of the 12–15 species ranked as being of ‘high risk’ in the present study, 11 (73%) have established viable populations in the Neretva catchment, whereas some of the ‘medium‐risk’ species [i.e.…”

Global patterns and clines in the growth of common carp Cyprinus carpio

“…Although in some of its non‐native areas of distribution, such as North America and Australasia, C . carpio is highly invasive (McCrimmon, ; Moyle, ; Koehn, ; Bajer et al ., ), it is also regarded as a (potential) threat in several other regions of Africa, Asia, South America and Europe (Fernández et al ., ; Britton et al ., ; Clavero & Villero, ; Macklin et al ., ; Maiztegui et al ., ; Piria et al ., ).…”

Alien freshwater fish species in the Balkans—Vectors and pathways of introduction

“…This study focuses on the alien fish species of the Balkan Peninsula, one of the world's biodiversity hot spots (Mittermeier, Turner, Larsen, Brooks, & Gascon, ) that possess the highest proportion of range restricted endemic fish species in Europe (Bănărescu, ; Barbieri et al., ; Kottelat & Freyhof, ; Simonović et al., ). Recent surveys from several Balkan countries, however, have revealed that 15%–23% of their fish fauna is alien (Barbieri et al., ; Piria, Tomljanović et al., ; Piria, Povž et al., ; Simonović et al., ), with certain catchments, such as the Danube River and Pamvotis Lake (Greece), having an ichthyofauna comprised of more than 50% and 80% of alien fishes, respectively (Leonardos, Kagalou, Tsoumani, & Economidis, ; Simonović et al., ). Furthermore, owing to the high level of endemism and the great conservational value of the Balkan freshwater fish species, introductions can have severe negative and irreversible impacts on the ichthyodiversity of the Peninsula (Barbieri et al., ; Ćaleta et al., ; Karapetkova & Zhivkov, ; Mrdak, Nikolić, Tošić, & Simonović, ; Povž, Gregori, & Gregori, ; Snoj, Razpet, Tomljanović, Treer, & Sušnik, ; Sušnik et al., ).…”

“…In the current study, 33.17% of all introduced fishes were found to be widespread. The most widespread species are gibel carp, pumpkinseed, brown bullhead ( Ameiurus nebulosus , Ictaluridae), Eastern mosquitofish and topmouth gudgeon, due to their high invasive potential (Perdikaris et al., ; Piria et al., b; Simonović et al., ). Species with a moderate distribution (15.38%) include the monkey goby ( Neogobius fluviatilis , Gobiidae) and bighead goby ( Ponticola kessleri , Gobiidae) in Croatia, the goldfish in Albania and Greece and the silver and bighead carp in most countries.…”