Investigating the genetic structure of trout from the Garden of Ninfa (central Italy): Suggestions for conservation and management

Abstract

Mediterranean populations of brown trout (Salmo trutta L. complex) have lost a large part of their genetic distinctiveness, mostly due to massive restocking, and the waters of the Gardens of Ninfa (province of Latina, central Italy, Site of Community Importance since 2013) are regarded as one of a few potential reservoirs of autochthonous trout lineages in the Tyrrhenian drainage of the Italian peninsula. In this study, nuclear and mitochondrial markers were used on brown trout samples from Ninfa to estimate non-Mediterranean influence in the population gene pool, potential changes of genetic structure over time and genetic relationships with other sites known (or suspected) to host native trout gene pools. Striking changes in both microsatellite and mtDNA allele frequencies over a 9-year time span were found and provided evidence of unrecorded stocking from the nearby Lake Fibreno. Results are analysed in the light of potential ecological consequences of such events on a longer time scale and provide a scientific background for fisheries management and conservation programmes in the area

The name of the trout: considerations on the taxonomic status of the Salmo trutta L., 1758 complex (Osteichthyes: Salmonidae) in Italy

“…In populations from Corsica, Sardinia and Latium, formerly attributed to Salmo macrostigma (Figure 1(c)), aDNA revealed the presence of AD and ME lineages, also observed in other museum specimens from Tyrrhenian Apennine side, and currently classified as Salmo cettii (see above). Similar findings were recently obtained by Fabiani et al (2017) for the "macrostigma" Latium population, harbouring indeed AD and ME haplotypes. As for S. carpio, a single specimen belonged to AD lineage, thus confirming that this lacustrine trout does not represent a peculiar evolutionary line, but probably no more than an ecotype of the lake Garda (Splendiani et al 2017).…”

Genotyping of Two Mediterranean Trout Populations in Central-Southern Italy for Conservation Purposes Using a Rainbow-Trout-Derived SNP Array

“…More recently, microsatellite markers have been extensively used, revolutionizing the study of population structure for fishery conservation genetics and management purposes [ 29 ]. In light of this, it is not surprising that several research studies for the genetic characterization of Italian Mediterranean trout populations have also taken advantage from this approach with interesting results [ 30 , 31 , 32 , 33 , 34 ].…”

Genetic changes caused by restocking and hydroelectric dams in demographically bottlenecked brown trout in a transnational subarctic riverine system

“…Measures against the negative consequences of anthropogenic barriers in riverine systems include construction of fish passes (Gouskov et al, 2016;Kraabøl et al, 2009;Rolls et al, 2014), introduction of non-native species (Caudron, Champigneulle, Vigier, Hamelet, & Guyomard, 2012; Fernández-Cebrián, Araguas, Sanz, & Garcia-Marin, 2014), release of hatchery-reared individuals (Fabiani et al, 2018;Hansen, Fraser, Meier, & Mensberg, 2009;Petereit et al, 2018;Quiñones et al, 2014;Thaulow, Borgstrom, & Heun, 2013;Vøllestad & Hesthagen, 2001), and supplementary stocking with local specimens. However, fish passes have generally been found to be insufficient to prevent population subdivision even in strongly migratory species like salmonids (Noonan, Grant, & Jackson, 2012).…”