The otter in Switzerland: Exterminated, returned and politically threatened

In 1888, the Confederation decided, through the Fisheries Act, to exterminate the otter. Hunting courses, bounties and state-funded trapping equipment followed. In 1952 the otter was placed under protection, but its population never recovered. In 1989 the last otter swam in Lake Neuchatel. In 1990 the Otter Group Switzerland, in a report to the then Federal Office for the Environment, Forests and Landscape (BUWAL), established the “end of the otter in Switzerland”. Then something happened that the authorities had thought impossible: in 2009 an otter was sighted near Reichenau in Grisons, having returned on its own paws. Since then it has been spreading slowly, along the Aare, Emme, Rhine, Ticino, Rhone and Inn. According to WWF, it has now been recorded in nine cantons, and in Grisons and St. Gallen it is raising young again. Yet the population is tiny: the FOEN Red List (2022) assumed barely more than ten individuals and classes the otter as “critically endangered” (CR). And while the return has barely begun, fishing associations and the recreational hunting lobby are already planning the next round of persecution.

Profile and biology

Characteristics and adaptation

The Eurasian otter (Lutra lutra) belongs to the mustelid family (Mustelidae) and the subfamily of otters (Lutrinae). It is 60 to 90 centimetres long, plus a tail of around 40 centimetres. Males weigh 7 to 12 kilograms. Its streamlined body, the webbed feet and the extremely dense fur (up to 70,000 hairs per square centimetre) make it a highly specialised aquatic hunter. Nose, ears and eyes sit at the same level, so that at the water's surface it can see, hear and smell at the same time. When diving, the ears and nose close hermetically, while the sensitive whiskers pick up the vibrations of fleeing fish.

Way of life and diet

The otter is mainly crepuscular and nocturnal and lives as a territorial solitary animal. A male claims a territory of around 10 to 15 kilometres of river, females somewhat less. It feeds mainly on fish, supplemented by crayfish, amphibians, mussels, birds and small mammals. Each day it needs around 15 to 20 per cent of its body weight in food, or roughly 1 to 2 kilograms. It spends three to five hours a day hunting. The otter cannot afford to overexploit its territory: it depends on healthy, reproducing fish populations. When otters are able to persist in the long term, a waterbody is doing well.

Red List status

In 1994, the otter was classified in Switzerland as 'extinct' (RE). Since its return, it was upgraded in 2022 to 'critically endangered' (CR). Globally, the IUCN classifies the species as 'near threatened' (NT). In the EU, the otter is strictly protected under the Habitats Directive (Annexes II and IV). The Bern Convention lists it in Appendix II (strictly protected animal species). The 2022 Red List justifies the classification by noting that the population comprises barely more than ten individuals and that the species reproduces only very rarely. In Switzerland, under Art. 7 of the Hunting Act (JSG) it is a protected species and is included on the FOEN's list of nationally priority species.

A history of extermination: a federal law as a death sentence

The Fisheries Act of 1888

Until the late 19th century, the otter was found along almost all waterways in Switzerland. The Federal Act on Fisheries of 1888 changed everything: Article 22 ordered that 'the extermination of otters and other animals particularly harmful to fisheries be encouraged as far as possible'. The cantons offered bounties: 30 francs for an otter's snout in the canton of Zug. State-run otter hunting courses were organised, and hunting dogs and leg-hold traps were funded. It was a bureaucratically planned, state-financed campaign of annihilation.

Protection came too late

As early as 1913, hunting bags fell to fewer than 10 animals per year. From 1917 onwards, the Swiss League for Nature Protection (today Pro Natura) campaigned for the protection of the otter. In 1952 the animal was finally placed under federal protection, but by then only around 150 otters were left in Switzerland. The population never recovered. The reasons were manifold: watercourses had become inhospitable through straightening, dams and the draining of wetlands. On top of this came chronic poisoning by PCBs (polychlorinated biphenyls), which, via the food chain, destroyed the breeding success of the females. In 1989 the last record of a wild otter in Switzerland was made at Lake Neuchatel.

More on this: Dossier: Hunting and Biodiversity

The return: back on its own paws

2009 to the present

In 2009, an otter was recorded in Switzerland for the first time again, at the fish ladder of the Reichenau power station in the canton of Grisons. The return happened naturally: the animals migrated in from Austria via the Inn and from France via the Rhone. On the Aare, it is assumed that the population was founded by the descendants of otters that escaped in 2005 from the Dählhölzli animal park in Bern. Since then, otters have been confirmed on six Swiss watercourses: the Aare, Emme, Rhine, Ticino, Rhone and Inn. In 2024, an otter was sighted in the canton of Zurich. In the canton of St. Gallen, the first record since the species' extinction was made in 2021 in the Rhine Valley; camera-trap videos from Sevelen showed offspring for the first time in 2024, and in December 2025 the otter reached the Linth plain (canton of St. Gallen). In the Grisons, the wildlife wardens again recorded young animals in the Upper Engadine in August 2025, and in December 2025 for the first time in the Chur Rhine Valley, making it the eighth confirmed breeding in the canton (Office for Hunting and Fisheries of the Grisons). In January 2026, an otter appeared at Selzach for the first time since 1935 in the canton of Solothurn. According to the WWF (October 2026), the species is now present in nine cantons. There is no current official population estimate; the 2022 Red List assumed barely more than ten individuals.

What the return means

The return of the otter is a natural process, not a human achievement. The animals come back of their own accord when conditions allow: enough fish, reasonably connected waterways and no targeted persecution. The Swiss Ornithological Institute in Sempach confirms: «The settlement and spread of cormorants and rooks are the result of better international protection.» The same applies to the otter. Its comeback shows that species protection works when it is allowed to. Yet that is precisely what is being called into question politically.

Threats: old enemies, new dangers

Habitat loss

Swiss rivers and streams are still heavily engineered. Straightening, dams, a lack of riverbank vegetation and insufficient residual flow downstream of power plants make large stretches unsuitable for the otter. The otter needs clear, shallow, fish-rich waters with natural bankside vegetation and plenty of places to hide. Engineered waterways offer none of this.

Road traffic

In a tiny population, every loss is existential. In 2025, two otters were killed by traffic in the St. Gallen Rhine Valley, including a female in October who had already had young, on the A13 near Sennwald. Bridges without bank passages force the animals onto the road. The foundation Pro Lutra intends to check as many bridges in Switzerland as possible for their «otter-friendliness» over the coming years.

Environmental toxins

Although PCBs have been banned in Switzerland since 1986, legacy contamination remains in sediments and waterways. In 2016, during maintenance work on the Punt dal Gall dam, PCB-containing particles entered the Spöl in the Swiss National Park. Four years later, a dead eagle owl with extreme PCB contamination was found. Water quality remains a limiting factor for the otter's spread.

Political threat: JSG revision and calls for culling

The greatest danger to the otter comes not from nature but from politics. During the 2020 JSG revision, BirdLife Switzerland, the Fondation Franz Weber and ProTier explicitly warned that beavers, lynx, otters, grey herons and goosanders were at risk of being placed on the list of species declared 'regulable'. The Swiss electorate rejected the revision with 51.9 per cent. But the pressure remains. In Bavaria, the state government tried in 2023 to permit the killing of up to 32 otters by ordinance. The Administrative Court of Appeal in Munich declared the blanket permit unlawful, and in 2025 it also halted the kill order for Upper Franconia (Setback for otter hunting in Upper Franconia). In Austria, five federal states permit killing by ordinance: according to WWF, 565 otters have been killed with official authorisation since 2020, 258 of them in Carinthia, 125 in Upper Austria and 106 in Lower Austria. According to WWF, there is insufficient scientific evidence that otters endanger fish species in flowing waters. Switzerland stands at a crossroads: will the otter once again be declared a 'pest' before it has even had a chance to recover?

Ecological significance: indicator, regulator, ecosystem engineer

An indicator species for water quality

The otter is a reliable indicator of the quality of a body of water. Where otters can persist in the long term, the water is healthy: rich in fish, rich in structure, clean. Its return is not a problem but a sign that restoration measures are working. Its absence was, for decades, an alarm signal about the state of Swiss waters.

Natural regulation of fish populations

As a solitary, territorial animal, the otter differs fundamentally from the cormorant: it cannot overexploit its fish stocks because it is tied to its territory. Its choice of prey regulates sick, slow and surplus fish. In near-natural waters with sufficient structure, no measurable negative effect on fish populations is to be expected.

Connecting waterways

The otter needs connected waterways. Its habitat requirements compel policymakers to advance river restoration, bank renaturation and the removal of barriers to migration. Anyone who protects the otter automatically protects hundreds of other aquatic species as well.

The 'pest' narrative: the return of an old lie

'The otter eats the waters empty'

The fish ecologist Clemens Ratschan, who has been studying the situation in Austria for years, knows of not a single case in which a flowing watercourse was left devoid of fish by the otter. The otter can reduce the fish stock in its territory, but it cannot wipe it out, because it depends on healthy stocks itself. In near-natural, structurally rich waters with enough shelter for fish, no measurable negative effect is to be expected. Where fish stocks are under pressure, the causes are almost always man-made: canalisation, dams, pesticides, climate warming, overfishing.

“The otter endangers fish farming”

In Switzerland, fish pond farms are far less common than in Austria or Bavaria, where the conflicts are greatest. To an otter, open fish ponds are like a henhouse with an open door to a fox. There, technical protective measures are needed: otter-proof fences, decoy ponds, night nets. Culling has demonstrably proved ineffective, as the example of Upper Austria shows. The solution lies in protecting the facilities, not in persecuting the species.

“The otter threatens the grayling”

In the Linth region, one of the last grayling spawning areas in Switzerland, the otter was detected in 2025. Concern for the endangered grayling is justified, but the otter is not the cause of its plight. The grayling suffers from habitat loss, climate warming, overfishing and pressure from cormorants. The negative effects of natural predators can be reduced if watercourses are near-natural and structurally rich and offer fish sufficient shelter. Using the otter as a scapegoat for man-made problems is the same strategy that led to its extermination in 1888.

What needs to change

Absolute protection of the otter in Switzerland: With a tiny population and a Red List status of CR (“critically endangered”), any discussion of “regulation” is absurd. The otter must under no circumstances be placed on the list of regulable species, whether through a revision of the JSG or through a Federal Council ordinance.
Comprehensive watercourse restoration: The otter's future depends on the quality of our waters. The Waters Protection Act obliges the cantons to carry out restoration. This duty must be implemented consistently, with otter-friendly banks, near-natural structures and continuous migration corridors.
Otter-friendly bridges and underpasses: Road deaths are a threat to the survival of a very small population. All bridges over waters inhabited or potentially inhabited by otters must be fitted with dry bank passages. The Pro Lutra foundation's bridge assessment project is the right approach.
Prevention instead of killing in conflicts with fish farms: Where otters visit fish farms, otter-proof fences, diversion ponds and technical protection devices must be funded. Killing is no solution: in Austria, hundreds of otters have been killed since 2020, with no scientific basis for its effectiveness. In Bavaria, the Munich Higher Administrative Court declared blanket killing unlawful.
Expand national otter monitoring: The Pro Lutra foundation and WWF carry out voluntary mapping through the 'Otterspotter' programme. However, systematic, nationally coordinated monitoring is indispensable in order to track population development and to base political decisions on data rather than lobby interests.
Clean up legacy PCB contamination: The remaining PCB sources in Swiss waters must be identified and cleaned up. The Spöl incident of 2016 shows that the contamination is still a real problem.

Talking points

“The otter eats the waters empty and must be regulated.” The otter is a territorial animal that cannot overexploit its own fish stock, because it depends on that stock's reproduction. Not a single documented case exists in which an otter has made a flowing water fish-free. The real causes of declining fish populations are river engineering, pesticides, global warming and overfishing.

“The return of the otter threatens fishing.” The managing director of the Swiss Fishing Association has himself described the return as a positive sign of water quality. Conflicts with fish farming can be resolved: diversion ponds, otter-proof fences and technical protection measures work, as experience from Germany and Austria shows. In Austria, killing has demonstrably not contributed to resolving conflicts.

“The otter must be included in the hunting act so that it can be regulated if necessary.” BirdLife Switzerland and the Fondation Franz Weber have been warning for years: anyone who puts the otter on the list of regulable species is repeating the mistake of 1888. The 2020 revision of the Hunting Act (JSG) was rejected by the people, among other reasons because it threatened to undermine the protection of otter, beaver and lynx. The 2022 Red List assumed barely more than ten animals in Switzerland. With a population this small, any discussion about “regulation” is not only pointless but dangerous.

“In Austria and Bavaria, the otter has caused massive damage. The same will happen in Switzerland.” Switzerland is not Austria: fish farming ponds are far less common here. The conflicts in Austria mainly concern open fish ponds, which offer easy prey. In flowing waters with intact habitat, the otter's impact on fish stocks is small or not measurable. Prevention is more effective and cheaper than persecution.

“The extermination of the otter was a mistake, but today's waters are no better.” The fact that the otter is returning on its own refutes this claim. Water quality has improved, even if it is not yet optimal. The return of the otter is an argument for more restoration, not for renewed persecution.

Quick links

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Related dossiers:

sources

Stiftung Pro Lutra: History and situation of the otter in Switzerland (prolutra.ch)
info fauna / CSCF: Swiss otter specialist unit (infofauna.ch)
WWF Bern and Solothurn: Otter spotter monitoring 2017–2024 (wwf-be.ch)
Canton of St. Gallen, Office for Nature, Hunting and Fisheries (2026): The otter has reached the Linth plain. Press release
Swiss National Museum / Aufdermauer, C. (2025): The last otter. Blog on Swiss history
Fondation Franz Weber (2020): Revision of the JSG. Otter fact sheet
BirdLife Switzerland: Revision of the Hunting and Protection Act, what is it about?
ProTier: Revision of the Hunting Act, a threat to the otter and other protected species
BUND Naturschutz Bayern / DUH (2024): Otter killing in Bavaria remains prohibited. Administrative Court ruling
Bern Convention: Appendix II (strictly protected animal species)
EU Habitats Directive: Annexes II and IV
Otter Group Switzerland (1990): Report to the BUWAL on the end of the otter in Switzerland
Federal Act on Fisheries (1888/1889), Art. 22
Federal Act on Hunting and the Protection of Wild Mammals and Birds (JSG, SR 922.0)
Ratschan, C. (2024): Otters and fisheries in Austria. In: Petri-Heil
Capt, S. (2022): Rote Liste der Säugetiere (ohne Fledermäuse) [Red List of Mammals, excluding bats]. FOEN / info fauna, Umwelt-Vollzug 2202
Office for Hunting and Fishing of the Canton of Grisons (2025, 2026): Press releases on otter reproduction in the Upper Engadine and in the Chur Rhine Valley
Canton of Solothurn (2026): Selzach: The otter is back in the canton for the first time since 1935. Press release of 16 January 2026
WWF Austria (2026): Report on the persecution of protected species

Our Standard

The history of the otter in Switzerland is a history of state-organised extermination. In 1888, the federal government decided to wipe it out. By 1989, the goal had been achieved. Then, after 20 years of absence, it came back of its own accord. Not because humans had planned it, but because nature is more resilient than politics. Today the otter lives in Switzerland only in a small, scattered population. It is listed on the Red List as 'critically endangered'. It is strictly protected under the Bern Convention and the Swiss hunting act. And yet its 'regulation' is already being discussed before it has even recovered. The fishing associations and the recreational hunting lobby are serving up exactly the same narratives as in 1888: 'harmful to fisheries', 'competitor', 'pest'. The conclusion is clear: the otter must remain absolutely protected in Switzerland. Its return is an opportunity, not a problem. This dossier is updated continuously whenever new figures, studies or political developments make it necessary.

More on the topic of recreational hunting: in our hunting dossier we bring together fact checks, analyses and background reports.