The otter in Italy and the Alps
The otter was a fundamental part of the Alpine river ecosystems until a few decades ago. While it was once common throughout the Italy and Europe, over the last century there has been a generalized collapse of populations. The peak of the decline was in the 1970s. By the end of the 1980s only a small population in the south of Italy and small residual populations in the centre remained, which also became extinct in the following decade. In 1984-1985, in the national census based on the standard method promoted by the WWF carried out in those years showed that this mustelid was absent from all northern regions (Macdonald and Mason 1983b; Cassola 1986); on that occasion a single "spraint" (name for an otter excrement) was found in Friuli Venezia Giulia, probably belonging to erratic specimens from Slovenia (Lapini 1986).
The main causes were the destruction and pollution of their habitat and the active persecution of the species, both for its valuable fur and because it was considered a "harmful" species as a competitor for fish. There were specialized hunters called "lontrari."
From the survey conducted by Cagnolaro in 1976, we know that in the Maritime Alps, most otters were found in the province of Cuneo where, in the decade preceding the survey, 16 specimens were slaughtered out of a total of 22 in the region. In the watercourses around Cuneo, otters were reported in the Vermenagna, Gesso and tributaries, Stura di Demonte had a substantial population, the upper river Po, the Maira, Grana, Marmora and Varaita streams; they were also reported in some stretches of the Bòrmida, Tanaro and Stura plains and for the Casotto, Corsaglia and Ellero streams in the Monregalese area. This historical information shows that the Maritime Alps, and also the Ligurian Alps, were the last stronghold of the otter before its disappearance.
In 1971 the otter was removed from the list of "pests", but it was with the subsequent Law n. 157 of 1992 that it was fully protected and officially considered as a specially protected species.
Currently, at European level, the otter is on the IUCN's Red List in the Near Threatened category (Near Threatened, NT - IUCN 2007,) because, although it has suffered a drastic decline over the years, it is now recovering in most European countries. But at the Italian level it is included in the category under Endangered (EN) according to the precautionary principle, since the population is certainly below 1000 and its distribution is disconnected.
The fundamental conservation policies undertaken in recent decades throughout Europe have favoured the return of the species in many countries, leading to a reversal of the trend.
In Italy too, the otter seems to be recovering, but there is a contrasting dynamic here: on the one hand, some portions of the area in central Italy (e.g. Sangro) and southern Italy (e.g. Carapelle) are expanding (Reggiani et al. 2001c; Fusillo et al. 2004; Prigioni et al. 2005a, 2007; Reggiani and Loy 2006) and on the other hand, in the Alpine region, this phenomenon is much slower. Until not so long ago there were only sporadic observations in the Alps or, sadly, the retrieval of dead animals along the Italian-Slovenian border, probably involving erratic specimens that suggests these were otters attempting to expand into other countries bordering the Alps.
The Alps can be an extreme habitat for otters, especially the western part, with few mountain passes available for the otter to cross.
Recently, otters have been confirmed in northeastern Italy in the Isonzo River and there are good prospects for their expansion towards the Veneto region. In 2008 they appeared in Italian Danube waters - along the Drava and tributaries in South Tyrol - where a first viable population of Austrian origin was formed and is still present today.
The return of the species to the Friuli Venezia Giulia region was initially reported when an adult found its way into the cooling tanks of Acciaieria Weissenfels (Danube Basin, Fusine in Valromana, Tarvisio, Udine). Subsequent investigations and the discovery of dead animals showed that the species was widespread throughout the rivers in the area (about 60 km of watercourses, all in the Danube Basin). The source of the population is certainly Austrian-Carinthian.
As regards the north-western sector, there were no longer any noteworthy reports. In the case of otters found in Ticino Lombardo and Piemontese these were escapees from two farms in regional parks. These individuals came from an English farm where they had been crossed with the Asian subspecies Lutra lutra barang. In the 1990s any reintroduction projects with these specimens were banned by ISPRA and the IUCN-SSC Otter Specialist Group. To date, the status, presence and distribution of this species in the Alps is still unclear. The first step towards possible European strategies to promote the expansion and natural conservation of the species primarily through the protection of its habitat is to take stock of the distribution and conservation status of the otter in the Alpine region. In Italy, the otter population (Lutra lutra) remains one of the smallest and most isolated in Europe. For this reason, a National Action Plan for the conservation of the otter (PALCO - downloadable here) was published in 2011, which contains detailed information on the biology, threats and actions to save the last populations living in our rivers.