Invasive alien species in Western Pomerania’s wetlands and protected areas

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This report can be downloaded as a pdf.

Colin Tate, RSPB 

Invasive alien species in Western Pomerania’s wetlands and protected areas

Threats, Perspectives and thoughts

10-17 July 2019

Erasmus +

Report author: Colin Tate, Administrator, RSPB Scotland

Table of Contents

Introduction 2

Agenda and description of areas 2

10 June 2019 – Namyślin 2

11 June 2019 – Ujście Warty National Park. 2

12 June 2019 – Ińsko Landscape Park, Bórbagno Miałka Reserve, and Szczeciński Landscape Park “Beech Forest” 3

13 June 2019 – Cedyński Landscape Park 6

14 June 2019 – Dąbskie Lake and Szczecin 6

15 June 2019 – Odra Delta Nature Park 7

16 June 2019 – Szczecin Lagoon 7

17 May 2019 – Woliński National Park 8

The importance of wetlands 8

Invasive alien species and the threat to biodiversity 9

What are invasive alien species? 9

Why invasive alien species are a problem 10

How Poland counteracts these threats 10

Collection and dissemination of data 10

The law and international obligations 11

Review of common invasive species in western Pomerania and control efforts 12

The American Mink (Mustela vison) 12

Control and monitoring efforts 13

Raccoon (Procyon lotor) 15

Control and monitoring efforts 16

Raccoon dog (Nyctereutes procyonoides) 16

Control and monitoring efforts 17

How does the problem of invasive species in Poland compare with that in Scotland? 17

Conclusion and learning points 18

Acknowledgements 19


In July 2019 staff from various natural heritage organisations in Scotland took part in a one-week NET training course in Poland. The course was funded by the Erasmus+ European Union programme and organised by ARCH. The host organisation was the European Union for Coastal Conservation (EUCC) Poland.

The aims of the NET programme are to improve management of our cultural and heritage assets and promote their benefits to a wider audience by training, inspiring and connecting Scottish professionals.

The NET programme encourages participants to share the learning from the visits as widely as possibly within and outside of their organisations. The organisations represented on this trip were:

RSPB Scotland

Scottish Natural Heritage

Loch Lomond and The Trossachs National Park

Participants on the course were asked to report on a subject and in a format most appropriate to the audience with which they wish to engage. My work at RSPB Scotland involves dealing with wildlife enquiries. I’ll be disseminating my take home messages from the trip to other staff and volunteers who answer wildlife enquiries within our organisation and, through them, to the general public.

Our visit to Poland looked at various nature conservation themes – wetland management, natural grazing methods, conservation, education and tourism in some of its protected areas. We also looked at a variety of threats to biodiversity such as climate change and the disappearance or fragmentation of habitats. This report focuses on one such threat – that of common invasive alien species. The report discusses the threat common invasive mammals pose and measures undertaken to control them. It also makes some comparisons with our experiences in Scotland. The report concludes with the main lessons learned in Poland while on the study tour.

Agenda and description of areas

Most of the sites visited were ‘protected areas’ of Poland, as defined by the Act on Protection of Nature 2004. Protected areas are places such as national parks, landscape parks, nature reserves, Natura 2000 designated areas and Ramsar sites.

10 June 2019 – Namyślin

Travelled to Namyślin (Boleszkowice Commune, West-Pomerania Region) for a three night stay in a local hotel.

11 June 2019 – Ujście Warty National Park.

Visited Ujście Warty – one of 23 national parks in Poland. Most national parks are divided into strictly and partially protected zones. Additionally, they are usually surrounded by a protective buffer zone called otulina.

Ujście Warty national park is also a ‘Ramsar site[1]’. This is a wetland of international importance under the Ramsar convention.

Ujście Warty national park is one of Poland’s precious ornithological areas. Consisting of marshes and pastures, it contains 280 bird species and is one of the most crucial bird breeding areas in the country.

Some of the species include: shelduck, gadwall, oystercatcher, black-necked grebe, graylag goose and white heron. Many of the species present are threatened by extinction: the aquatic warbler, corncrake, spotted crake, black tern and whiskered tern.

In autumn there are flocks of 100,000 arctic geese (bean and white throated). During the winter season many migrating birds stop here en-route to their final destinations. Whooper swans, mute swans, white-tailed eagles, rough-legged buzzards all winter here.

12 June 2019 – Ińsko Landscape Park, Bórbagno Miałka Reserve, and Szczeciński Landscape Park “Beech Forest”

A landscape park is defined as “an area protected because of its natural, historical, cultural and scenic values, for the purpose of conserving and popularizing those values in conditions of balanced development.”

As at 9 May 2009 there were 122 designated Landscape Parks throughout Poland, covering a total area of approximately 26,100 square kilometers.

The Ińsko landscape park was established in 1981 and covers around 177 square kilometers. The aim of establishing this park was to preserve the intact form of post-glacial landscape along with the whole range of natural values of this area. There are many lakes within the park, the largest of which is Lake Ińsko. Water accounts for more than 8.5% of the total area of the park.

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Figure 1: View over Lake Ińsko

Ińsko is very diverse. There are many hills, valleys and forests. A large part of the park is wilderness.

There are around 142 bird species in the park and over 700 species of vascular plants – a third of all Polish species.

There are 5 nature reserves within the park – ‘Kamienna Buczyna’, Wyspa Sołtyski’, Głowacz’, Krzemieńskie Źródliska’, Bórbagno Miałka’. The Bórbagno Miałka Reserve falls within the limits of two areas of the Natura 2000 network. These sites are nature protection areas within the European Union.

Bórbagno Miałka is around 49 hectares. In 2017 it was classified as an example of peatland to preserve the ‘mosaic of peat bog habitats with the characteristic flora and fauna’.

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Figure 2: Peat bog at Bórbagno Miałka

Szczeciński Landscape Park was also established in 1981 and covers 91 square kilometers. Its full name refers to the dense forest known as Puszcza Bukowa (“beech forest”), which covers most of the area of the Park.

The area was once home to the brown bear, the lynx, the wildcat and European mink. Today beech martin and the edible dormouse can be found here along with many rare bird species.

13 June 2019 – Cedyński Landscape Park

Bird watching on the area created by Green Valley of Odra and Warta Rivers.

Cedyński Landscape Park

Cedyński landscape park is in the Lower Oder valley. It is a part of the Landscape Parks of the Lower Oder Valley and of the European Ecological Network Natura 2000 ‘Lower Oder’.

The Cedyński landscape park features a post-glacial landscape. There are numerous moraines, lakes, ponds, streams and gorges. There are many observation points to view the picturesque Oder valley and surrounding fields. The diverse landscape is a perfect habitat for many endangered species. 194 species of birds have been observed here and 39 species of mammals including the wolf, bat, beaver and otter.

14 June 2019 – Dąbskie Lake and Szczecin

Visit to office of West-Pomerania Landscape Park Management.

The study group then visited Dąbskie Lake and explored the area by boat. The Lake is a unique area of islands and water close to the city of Szczecin. It is known locally as ‘little Amazonia’ and is rich in bird life.

A body of water surrounded by trees

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Figure 3: Dąbskie Lake

Sightseeing in the city of Szczecin, capital of the West Pomerania Voivodeship. Szczecin is on the delta of the Odra River, and several of the Odra’s confluents flow through the city. It’s a major seaport and one of the largest cities in Poland. The German-Polish frontier is close to Szczecin, and Berlin is only 120 km away. Szczecin is mostly about water and lush verdure: rivers, lakes, woods and parks take up half of the city area – so it was particularly interesting for the study group to see the city and how nature flourishes in nearby Dąbskie Lake.

15 June 2019 – Odra Delta Nature Park

The Odra Delta Nature Park is a complex coastal ecosystem, consisting of coastal meadows, forests and wetlands on the eastern part of the Szczecin lagoon.

Located within 2 Natura 2000 sites the park covers approximately 4000 hectares. The park has introduced natural grazing methods (Konic horses and Highland cows) to maintain biodiversity and is heavily involved in connecting local schoolchildren with nature and ‘soft’ tourism development.

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Figure 4: A herd of highland cows used for grazing

16 June 2019 – Szczecin Lagoon

Visited the Szczecin Lagoon – a complex of Natura 2000 sites and enjoyed cultural aspects of the region.

The Szczecin lagoon is in the Oder estuary and shared by Germany and Poland. The area falls within the network of Natura 2000 habitats. It is situated at the meeting point for fresh water and sea water habitats. The lagoon is home to a wide variety of birds including cranes, white-tailed eagles, kingfishers, black and red kites and herons.

Numerous mosses and rare vascular plants occur in the lagoon and the diverse coastal zone.

There are many architectural monuments, water sports centres, harbours, beaches and museums nearby. The lagoon can be admired from various lookout points.

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Figure 5: The Szczecin lagoon

17 May 2019 – Woliński National Park

Established in 1960, Woliński national park covers 109 square kilometers. The protected land features 4 post glacial lakes, a sandy strip of southern Baltic coast and the highest cliffs in Poland.

The park is an area of outstanding natural diversity and home to 13000 species of vegetation and around 230 species of birds as well as many mammals and insects, including Poland’s largest beetle.

The importance of wetlands

Poland is fortunate to have several important wetland areas and, as the agenda above demonstrates, the study visit was designed to look at some of the most important ones in Western Pomerania.

A wetland is defined as any land area that is saturated or flooded with water, either seasonally or permanently. They can be either inland such as lakes, aquifers and marshes or coastal, as mangroves, estuaries and coral reefs. Naturally functioning wetlands provide a range of benefits and services for people’s livelihoods and well-being, including food, fibre, flood protection, water purification and support for cultural values, as well as water supply.

Wetlands are extremely rich in biodiversity. Water birds use wetlands for most of their life. The most important wetlands for birds are lakes, rivers and streams, bogs, marshes and swamps and coastal lagoons. At least 12% of globally threatened birds depend on wetlands.

Wetlands are extremely vulnerable however. The use of water and over extraction from natural water systems has affected most of the wetlands on earth. Human impacts include:

Dams (which change the course and ecology of rivers)


Water extraction

Tourism and development

Climate change also has implications for many wetland areas. Warm winters and lack of snow cover during that time results in low water levels in rivers in the spring. The lack of seasonal floods, droughts and a constant lowering of the water level all accelerate the decrease in wetland habitat from the landscape.

Invasive alien species and the threat to biodiversity

Invasive alien species are also a major threat to biological diversity on a global scale, not just to wetlands. A recent UN report[2] identified invasive alien species as one of the top 5 threats to biodiversity worldwide and warned that 1 million species are at risk of extinction. Based on a review of about 15,000 scientific and government sources and compiled by 145 expert authors from 50 countries, the global report is the first comprehensive look in 15 years at the state of the planet’s biodiversity. The report authors ranked the major drivers of species decline as (1) changes in land and sea use; (2) direct exploitation of organisms; (3) climate change; (4) pollution and (5) invasive alien species.

“The evidence is crystal clear: Nature is in trouble. Therefore we are in trouble,” said Sandra Díaz, one of the co-chairs of the Global Assessment Report on Biodiversity and Ecosystem Services.

What are invasive alien species?

An alien species is a species introduced by human (deliberately or accidentally) beyond its natural geographical range. The term does not apply to species spontaneously spreading beyond their natural ranges. Alien species may lack natural predators in their new environment, allowing them to breed quickly and spread without limits to eventually take over a natural area.

An invasive species is a species to colonise in new areas and environments, having negative and sometimes catastrophic impact on eco systems. Not every alien species is an invasive one. In Europe there are over 12000 alien species, around 15% of which are invasive.

The European Union defines “invasive alien species” (IAS) as animals or plants that are introduced accidentally or deliberately into a natural environment where they are not normally found, with serious negative consequences for their new environment.

Why invasive alien species are a problem

In their new habitat, invasive alien species become predators, competitors, parasites, hybridizers and diseases of native plants and animals.

It takes the right conditions for an alien species to become established and grow. Most introduced species do not become permanently established in their new environment. They either find the wrong type of conditions for survival or they are unable to produce enough offspring to maintain a viable population. For those species that can reproduce and survive, most never cause significant problems. They survive, spread and reproduce but generally do not pose a threat to economy, environment or society.

Some introduced species are, however, able to flourish in their new location. They have the right biological properties that allow them to grow quickly in numbers. In addition, they are usually able to reproduce and spread quickly often out-competing native plant and animal species for food, space and water.

The impact of invasive alien species on native species, ecosystems and habitats is severe. They represent a major threat to native plants and animals in Europe, causing damage worth billions of Euros to the European economy every year. 

In Europe, there are over 12,000 alien species, 15% of which are invasive. According to a recent report[3], 354 threatened species (229 animals, 124 plants and 1 fungus) are specifically affected by IAS (which accounts for 19% of all threatened species in Europe).

How Poland counteracts these threats

In Poland the problem of invasive alien species is well recognised although it is only in recent decades that concerted efforts have been undertaken to deal with it.

Collection and dissemination of data

The collection and disseminating on invasive alien species are widely recognised as crucial components in solving the problems they pose.

In 1999 a database on species which have been introduced to Poland was developed at the Institute of Nature Conservation, Polish Academy of Sciences in Krakow for the Ministry of the Environment. In 2003, thanks to a grant from the US State Department, part of the data was translated and made accessible on the Internet. Currently there are 1782 alien species of plants, animals and fungi in the database.

The Polish database became a part of NOBANIS (European Network on Invasive Alien Species; which is an important gateway to data on invasive alien species in Northern and Central Europe. The database was also the main source of data from Poland provided for the DAISIE project (Delivering Alien Invasive Species Inventories for Europe;, whose aim was to develop a database of on all alien species in Europe. In 2009, the database structure was significantly changed, according to guidelines developed by GISIN (Global Invasive Species Information Network;

The level of detail in the species accounts ranges from name to detailed datasheets.

The law and international obligations

The protection of water birds and their habitats is a priority stated in several international obligations and conventions on nature protection such as the Ramsar Convention.

This means that specific actions must be taken to reduce the negative impact of environmental changes. Protection measures must be introduced that will stop the transformation of bird habitats and reduce the pressure of invasive predators. Active protection of bird nesting sites is recommended in key habitats, especially national parks.

In May 2004 Poland became a member of the European Union. This also brought with it obligations such as submitting proposals for Natura 2000 sites which met the same criteria as other EU member states.

There are two principal pieces of legislation concerning invasive species in Poland. At the national level the issue is regulated by Article 120 of the Nature Conservation Act which prohibits the relocation of the listed species and their introduction into the natural environment.

The annex to the regulation defines plants and animals that could pose a threat if released into the natural environment.

At the EU level, the relevant legal act in force is the Regulation (EU) 1143/2014 on the prevention and management of the introduction and spread of invasive alien species.

In 2016 the Commission Implementing Regulation (EU) 2016/1141 came into force, adopting a list of invasive alien species of Union concern pursuant to Regulation 1143/2014.

Review of common invasive species in western Pomerania and control efforts

The study group was presented with information on several common invasive species mammals and plants in the areas visited, some of which are discussed below.

The American Mink (Mustela vison)

The American mink is a species that has experienced unprecedented ecological success in the 20th century. This can be seen in the dynamic increase in its zoological range and in its effective adaptation to new areas.

The driving forces of this success are the rapid intensification and globalization of mink farming which is accompanied by the introduction and rapid spread of the species outside its natural range.

Today the American mink is the most commonly farmed fur animal in the world. An estimated 5.4 million mink skins were produced in Poland in 2012. As for today 340 of the biggest mink producers in Poland have joined the European Fur Breeders Association and over 15% of the total European mink production originated from this country[4].

Mink were first observed in Poland in the middle of the last century. Within the last 60 years it has colonised most of Poland.

Modern factory mink farms are located mainly in the Western and North-Western part of the country. The West Pomeranian voivodeship comes with the second largest number of farms (after Greater Poland voivodeship) with 71 fur farms of which 57 are mink farms[5].

The mink is an expansive predator which can walk many kilometers to find suitable hunting grounds. The females live on an area of 8-20 hectares. The territory of the male is much larger and can range up to 800 hectares. They live in solitude or with their offspring in tree hollows or burrows they have dug themselves. These can be up to three meters deep.

The American mink preys on birds, their eggs and nestlings and has few natural enemies.

The effects of mink expansion are evident. In the Ujście Warty National Park the losses in protected bird species due to mink predation range up to 40-70% of every brood[6]. Park workers blame the nearby mink farms. Proximity of mink farms relates closely to the size of wild mink populations and threatens bird biodiversity in the national parks. Genetic variability of American mink in the national parks has been established and the impact of escaped mink measured. This shows a constant influx of escapees to wild populations.

Control and monitoring efforts

Since 2009 it has been legal to hunt American mink all year round in Poland using guns and live traps.

Between 2011 to 2014 and EU LIFE project for the protection of water birds in five Polish national parks included the removal of mink from protected important bird areas.

The key areas and seasons for most effective protection where identified. Personnel were trained so these actions could be continued when the project was finished. The most basic method for the reduction of predators such as the American mink was to capture them alive using traps. Floating rafts are used to identify mink tracks. Once the presence of mink is confirmed in an area, traps are set on the rafts.

To increase the effectiveness of removing mink (and raccoon), the number and trap placement as well as timespan were adjusted to match the density of the populations and home range sizes of the animals in different parks. Over 300 traps were used in the project and as a result 829 American mink and 171 common raccoons were removed.

Additional protection such as electric fences were also given to colonies of ground breeding birds. Access to tree mounted nesting boxes by predators was also hindered through the installation of special devices in the form of spiky rings and metal collars on tree trunks.

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Figure 6: Example of nest protection at Ujście Warty National Park

During the EU LIFE project a public awareness campaign took place which created a positive public attitude to the problem of invasive species. Educational materials were also widely distributed.

Mink remain a persistent problem however. In the absence of practical possibilities of its permanent eradication from Poland, local eradication programs on vulnerable areas (eg, waterfowl breeding sites), as well as large−scale population size control, promotion of natural enemies and competitors, and improvement of living conditions of its prey are most recommended. The most important in monitoring and control programs of alien populations is limitation of farm−animals escapes and recognition of methods for their unambiguous identification. Indisputable determination of the free−ranging animals’ origin would allow for taking the appropriate actions against owners of the unsafe farms. At the same time, implementation of a holistic and systemic approach to solve the problem of the presence of American mink in the natural environment would help to fulfil Polish obligations resulting from ratified international conventions and EU law.

Raccoon (Procyon lotor)

The raccoon is one of the most recently recorded alien species in Poland. Originally it is native to North America. In 1934 two pairs of raccoons were introduced into central Germany and some animals were also imported to Belarus which borders Poland. Individuals migrated from both directions and colonised areas of Poland. Raccoons were also bred for in many regions of Europe including Poland. Raccoons are also kept as pets.

The raccoon is a medium-sized carnivore originating from North America with a distinctive black eye mask and a ring and bushy tail.

The first record of raccoons in Poland dates to 1970. Since then there have been abundant sightings. However, the process of dispersion of the raccoons within the country has not been documented.

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Figure 7: Raccoon (Procyon lotor)

Between 1982 and 2009 questionnaires were sent to forestry workers in western and central Poland and to try to gauge the extent of the invasion and expansion of raccoons in Poland[7]. Separate questionnaires were prepared for national park workers.

Raccoons were recorded 312 times during the years under the questionnaire study. Raccoons were most often seen in western and Northwestern parts of Poland. Forest habitat and regions rich in water were most often reported as sites of raccoon sightings. Raccoons were relatively rare in urban environments. The fewest records were reported from regions in the east of the country.

Raccoons were common and protected areas. The most frequent sightings occurred in the Ujście Warty National Park (at least 24 records between 1995-2009).

Raccoons are versatile carnivores, hunting in a wide range of habitats. They can climb and swim. They are omnivorous and opportunistic, eating eggs, chicks and adult birds especially waterfowl. Their impact on biodiversity can be severe, especially Natura 2000 wetlands. They are known to damage fruit trees, vineyards and chicken farms and they can carry important diseases and parasites such as rabies round ones and toxoplasmosis.

Control and monitoring efforts

In Poland it has been legal to hunt raccoons all year round since 2009. Unfortunately, this seems to have had little effect on slowing down population expansion. Trapping is also used as a control measure. Despite local successes, total eradication of the species seems impossible and further colonisation of formally raccoon free areas is to be expected. The best management plans appear to consist of monitoring, control, research and communication.

Raccoon dog (Nyctereutes procyonoides)

The raccoon dog is named for its superficial resemblance to the raccoon. It is unrelated to raccoons and is a close relative of true foxes rather than the domestic dog. The raccoon dog has a long torso and short legs. Its head resembles that of South American foxes (particularly crab eating foxes) but they are not closely related.

The raccoon dog is a great tree climber. They are omnivores that feed on insects, rodents, and amphibians, birds, fish, reptiles, molluscs, carrion, and insectivores, as well as fruits, nuts, and berries. The also prey on waterfowl, passerines, and migrating birds.

Originally from eastern Asia, in the 1920s the raccoon dog was brought to various European countries which were part of the former Soviet Union. It was first recorded in Poland in 1955. By 1960 raccoon dogs were found mostly in north eastern Poland but also in areas located close to the western border. Since 2011 the species has been recorded in nearly all regions of Poland. However, little is known about it density, colonisation, ecological parameters of population and possible interactions between them and other predators in Western Poland.

Research in Poland suggests the raccoon dog prefers forests and may forage in fields.

The raccoon dog is one of the most successful alien carnivores in Europe thanks to its high reproductive capacity, flexible feeding habits and adaptive behavior. It is also a very important vector of rabies, parasitic worms, tix, sarcoptic mange and other parasites and diseases dangerous for wildlife as well as for humans.

Control and monitoring efforts

Action includes a ban on keeping on selling the species, a rapid eradication obligation of newly emerging populations and the management of established populations to prevent the species from becoming a wider problem and to keep them out of protected areas.

A small brown animal

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Figure 8: Raccoon dog (Nyctereutes Procyonoides)

How does the problem of invasive species in Poland compare with that in Scotland?

Scotland is fortunate in that neither raccoons nor raccoon dogs pose a problem. There are occasional sightings, but these are mainly escapees from zoos or private collections.

The American mink however is present throughout the UK, not just Scotland. As in Poland, it was introduced to establish fur farms. The first Scottish fur farm appeared in 1938 and since then there have been numerous escapes and deliberate releases.

The first reports of mink breeding in the wild were reported in 1962 in Aberdeenshire. Mink spread rapidly between 1962 and 1974 mainly dispersing from fur farms in the Firth of Forth and Grampian areas. By 1980s mink were reported in the Great Glen.

Mink are now widespread throughout Scotland except for the far north and some of the Scottish Islands.

The fur farming industry was banned in Scotland in 2000 unlike in Poland where fur farms are still very active.

Despite this mink continue to cause many problems in Scotland. They were thought to be responsible for the disappearance of the moorhen from Harris and Lewis. They are also credited with the collapse in water vole populations.

The Hebridean Mink Project began in 2001. Its main aim was the total eradication of the American mink from the Western Isles, thus preventing further losses to internationally important populations of ground nesting birds.

A concentrated trapping effort began on South Harris. Work began by targeting mink in the Uists and Benbecula. Following initial success, it expanded to South Harris. A concentrated trapping effort was established and the work carried out in a directed and methodical manner. It moved from South Harris, north and west through the Lewis peatlands finishing at the north western tip of the Hebrides, the Butt of Lewis.

The trapping cycle took around 7 months to complete then began again. The project team began with a network of around 7500 traps which were permanently sited. These were augmented, where necessary, with mobile traps. Individual trappers (of which there were 12) walked an allocated route of between 12-20 km per day, servicing up to 30 traps.

Phase II saw a reduction in the number of staff and the trapping effort reduced. Planned monitoring of the remaining mink population increased, however.

In 2018 the Hebrides were declared ‘mink free’ after the 17-year project. Terns, waders and sea birds were reported to be flocking back to the area and the project was hailed a success.

Large scale mink control began on the Scottish mainland in 2006[8]. The Scottish Mink Initiative began in 2011 demonstrating the mink control could be coordinated on a very large scale using a project-based approach.

A review in 2015 looked back at the previous 10 years of mink control. The review noted that mink abundance could be halved following four years of control and reduced to <10% by year ten.

Conclusion and learning points

From a personal point of view, I have returned to Scotland with an insight into how Poland manages its important protected areas, wetlands and coasts to preserve its biodiversity and natural assets.

For me the main learning themes were:

Poland’s recognition of the importance of its natural and cultural assets. We investigated and explored some of network of protected areas in Western Pomerania as defined by the Act on Protection of Nature.

The importance of wetlands for biodiversity. We saw at first hand the rich wildlife that can thrive in protected areas when it is well managed.

Threats to the wetlands from climate change. Disappearance of wetlands is an outcome of climate change. Large scale weather fluctuations such as heavy rains and floods, for example, can pose a threat to breeding birds. Factors like this contribute to shrinkage of suitable breeding areas for water birds.

Many breeding habitats have been degraded because of human activity over the years. Drainage in some areas has resulted in hydrological changes which in turn provided conditions for unnatural growth of reeds where sedges and mosses used to thrive.

Lack of mowing/cattle grazing has caused formation of trees and bushes. Consequently, open spaces have sometimes become inaccessible to breeding birds.

The introduction of invasive alien species has resulted in the decrease in numbers of native species. The main reasons are increased predation following the new predator’s arrival and the inability of native species to adapt quickly enough to avoid these new predators.

The most common species of invasive alien mammals – the American mink, the raccoon and the raccoon dog have had a profound impact on local populations of water birds.

Poland and Scotland have both been affected by the American mink and have sought to tackle the problem in similar ways with varying degrees of success. Scotland does not have a large-scale problem with either the raccoon or the raccoon dog.

The American mink seems unlikely to disappear entirely from the landscape of either country any time soon. In Poland local eradication in vulnerable areas has been the most successful control method. It has also been important to discover the origin of captured specimens so that action can be taken against any irresponsible fur farmers.


Many thanks to Erasmus+, the funding agency, and to Arch, the project promotors. A special thank you to our host Dr Kazimierz Rabski of the Society for the Coast and all the guides who gave us such a wonderful insight into this awe-inspiring landscape.

  1. In the 1960s countries and non-governmental organisations concerned about the increasing loss of degradation of wetlands for migratory water birds negotiated a treaty. It was adopted in 1971 in the Iranian city of Ramsar and came into force in 1975. It became known as the ‘Ramsar Convention’.

    The Convention’s mission is “the conservation and wise use of all wetlands through local and national actions and international cooperation, as a contribution towards achieving sustainable development throughout the world”. The convention became effective in Poland on 22 March 1978. Poland has 19 Ramsar sites.

  2. A 40 page ‘summary for policy makers’ of the full report was released on 6 May 19 in Paris, prior to publication of the full report


  4. “Poland has joined EFBA”,

  5. Data taken from the Veterinary Office registers in September 2013. See

  6. M Bartoszewicz, A Zalewski, American Mink, Mustela vison diet and predation on waterfowl in the Slońsk Reserve, western Poland 2003

  7. Expansion of the raccoon Procyon lotor in Poland

  8. Two large scale projects in NE Scotland and in the Cairngorms National Park (2006-2009), then another pilot, the North West Highlands Mink Control Project (2009-2011).

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