| Title | Non-native fish assemblages display potential competitive advantages in two protected small and shallow lakes of northern Italy |
| Abstract | The introduction and establishment of non-native fish species is a widespread phenomenon in freshwater ecosystems, including small and shallow lakes. However, these ecosystems are often not considered in conservation and ecological studies and a few information is available on their fish communities and the impacts of biological invasions. Here, standardized fish surveys (gillnetting and electrofishing) and stable isotopes analysis (SIA) of carbon and nitrogen (?13C and ?15N) were combined to assess fish community composition, trophic structure and trophic diversity, and to characterize the interspecific trophic interactions (as isotopic niches and their relative asymmetric overlap) of the native and non-native species (NS and NNS, respectively) found in two protected small and shallow lakes, San Michele and Campagna (northern Italy). In San Michele, 92% of the fish caught were NNS and both the individual and biomass per unit effort were dominated by NNS, particularly by the invasive Lepomis gibbosus L. and Ictalurus punctatus (Rafinesque, 1818). In Campagna, 5.6% of the fish in the total catches belonged to NNS and the numeric and biomass abundances of the assemblage were dominated by the NS Alburnus alborella (Bonaparte, 1841). SIA revealed that NNS had greater trophic structure and were exploiting a wider range of resources (as per Layman metrics) and had a higher asymmetric overlap than NS assemblages in both lakes. This was also evident when species-specific isotopic ecology was considered, underlining that, in both lakes, NNS (particularly the NNS Ameiurus melas (Rafinesque, 1820)) may have a competitive advantage over NS in case of limiting resources. The results thus pointed to a worrying conservation status of these lakes that may mirror the condition of other Italian shallow and small lakes highlighting the need to implement management actions to preserve these valuable ecosystems. |
| Source | Global Ecology and Conservation 35 (June) |
| Keywords | biological invasions; isotopic niches; stable isotopes; niche overlap; Ameiurus melasLepomis gibbosus |
| Journal | Global Ecology and Conservation |
| Editor | Elsevier, Amsterdam, Paesi Bassi |
| Year | 2022 |
| Type | Articolo in rivista |
| DOI | 10.1016/j.gecco.2022.e02082 |
| Authors | De Santis V.[1], Cicala D.[1], Baneschi I.[2], Boschi C.[2], Brignone S.[1], Iaia M.[1], Zaupa S.[1], Volta P.[1] |
| Text | 466299 2022 10.1016/j.gecco.2022.e02082 biological invasions; isotopic niches; stable isotopes; niche overlap; Ameiurus melas Lepomis gibbosus Non native fish assemblages display potential competitive advantages in two protected small and shallow lakes of northern Italy De Santis V. 1 , Cicala D. 1 , Baneschi I. 2 , Boschi C. 2 , Brignone S. 1 , Iaia M. 1 , Zaupa S. 1 , Volta P. 1 1 CNR IRSA, Largo Tonolli 50, VB, 28922 Verbania Pallanza, Italy; 2 CNR IGG, Via Moruzzi 1, 56124 Pisa, Italy The introduction and establishment of non native fish species is a widespread phenomenon in freshwater ecosystems, including small and shallow lakes. However, these ecosystems are often not considered in conservation and ecological studies and a few information is available on their fish communities and the impacts of biological invasions. Here, standardized fish surveys gillnetting and electrofishing and stable isotopes analysis SIA of carbon and nitrogen 13C and 15N were combined to assess fish community composition, trophic structure and trophic diversity, and to characterize the interspecific trophic interactions as isotopic niches and their relative asymmetric overlap of the native and non native species NS and NNS, respectively found in two protected small and shallow lakes, San Michele and Campagna northern Italy . In San Michele, 92% of the fish caught were NNS and both the individual and biomass per unit effort were dominated by NNS, particularly by the invasive Lepomis gibbosus L. and Ictalurus punctatus Rafinesque, 1818 . In Campagna, 5.6% of the fish in the total catches belonged to NNS and the numeric and biomass abundances of the assemblage were dominated by the NS Alburnus alborella Bonaparte, 1841 . SIA revealed that NNS had greater trophic structure and were exploiting a wider range of resources as per Layman metrics and had a higher asymmetric overlap than NS assemblages in both lakes. This was also evident when species specific isotopic ecology was considered, underlining that, in both lakes, NNS particularly the NNS Ameiurus melas Rafinesque, 1820 may have a competitive advantage over NS in case of limiting resources. The results thus pointed to a worrying conservation status of these lakes that may mirror the condition of other Italian shallow and small lakes highlighting the need to implement management actions to preserve these valuable ecosystems. 35 Published version https //www.journals.elsevier.com/global ecology and conservation Non native fish assemblages display potential competitive advantages in two protected small and shallow lakes of northern Italy DE_SANTIS_June_2022.pdf Articolo in rivista Elsevier 2351 9894 Global Ecology and Conservation Global Ecology and Conservation Global Ecology and Conservation GECCO ZAUPA SILVIA mattiaiaia IAIA MATTIA CICALA DAVIDE BRIGNONE STEFANO vanessadesantis DE SANTIS VANESSA pietro.volta VOLTA PIETRO chiara.boschi BOSCHI CHIARA ilaria.baneschi BANESCHI ILARIA |
