The Ringed Seal Archipelagos of Lake Saimaa

Description

The planned property includes parts of Lake Saimaa, located in south-eastern Finland, which is the largest lake in Finland (4 400 square km²) and among the four largest lakes in Europe. The national serial nomination would be based on Natura 2000 areas within the lake that are the most important breeding areas for the endemic Saimaa ringed seal (Phoca hispida saimensis), of which the endangered population does not exist anywhere else in the world other than Lake Saimaa. The lake´s open waters, sheltered bays, small rocky islets and boreal forested islands provide a varied living and breeding environment for several other fish, insect, bird and mammal species.

After the last glaciation in the area, the ice sheet melted, around 11 000 years ago. Lake Saimaa was shaped as a result of land uplift and was isolated over 9 500 years ago from the Baltic Sea. In the first stage, the Great Saimaa lake system connected eastern Finland’s lakes together before the separation resulting from the land uplift. Due to the land uplift and leaning after glaciation, the shape of the water basins has been changing and the direction of the runoff changed dramatically 6 000 years ago, which caused the water from Saimaa to run through the Vuoksi outlet to Lake Ladoga. The lake has been an important passageway and has had settlements in the area for thousands of years. The rock paintings in the area are around 5 000 years old.

Lake Saimaa represents the Finnish lake district area, and its catchment basin covers nearly all of eastern Finland. In its current form, the whole lake is 180 km in length and 140 km in width. This beautiful lake, with its 14 000 islands, has a fragmented, maze-like structure and an extraordinarily long shoreline of 14 850 km. Lake Saimaa is characterised by clean, oligotrophic freshwater and narrow straits between numerous islands varying together with large water bodies. In addition, the ridges formed by ice during the glaciation, bare craggy shorelines and some sandy beaches bring variation to the landscape. The landscape also varies within the four seasons in the north, and the whole lake is ice covered, normally from early-mid December to the end of April.

Justification of Outstanding Universal Value

Lake Saimaa is the only habitat of the endemic endangered Saimaa ringed seal. This landlocked subspecies was created through the geological processes (e.g. last ice age and land uplifting) in the past and is in the middle of its evolution process. This seal is an example of adaptation to a new kind of environment after being isolated in a freshwater lake. The landlocked Saimaa freshwater habitat has oligotrophic shallow waters and is a relatively cold environment as a change from the earlier wide marine habitats of ringed seals. As the isolated ringed seal has adapted to the Saimaa habitat, it has developed special and unique behaviour patterns differing from its relatives, such as solitariness and breeding totally in the subnivean lairs. In addition, the Saimaa ringed seal is the only seal living and breeding so close to human settlements. Lake Saimaa is the most representative site of a landlocked freshwater lake system habituated by seal subspecies, which its Outstanding Universal Value is based on. Lake Saimaa represents an outstanding freshwater ecosystem that includes many conservation areas in their natural state and provides living environments for several relict species.

The endemic Saimaa ringed seal is interesting also from scientific perspectives; the seal has high conservation value and tells a story of successful conservation history. The endangered Saimaa ringed seal population is currently at around 400 individuals. After the isolation to Lake Saimaa 8 000-9 000 years ago, the population went through a bottle neck that lasted hundreds of years. It has been suggested that the population was even up to 2 000-4 000 individuals around 5 000 years ago before a dramatic decline that lasted all the way to the 1980s, when the population was at its lowest, around 130-160 seals. A significant challenge for the conservation efforts is that the high trophic-level mammal species, like the Saimaa ringed seal, are slow to reproduce, especially when considering the separated subpopulations in Lake Saimaa that slows down the population growth. Furthermore, this ice- and snow-associated species faces challenges due to the climate change effects in its breeding habitat. Still, the conservation aims have been productive, and the population is currently growing. In addition, the strengthening population is currently returning to inhabit its old breeding areas where it had earlier disappeared from.

Criterion (ix): Lake Saimaa and its special ringed seal are an outstanding example of representing significant adaptation to the lake environment after the last ice age and isolation from the marine environment. The Saimaa ringed seal is an example of a significant ongoing biological process, the evolution and speciation in the freshwater ecosystem. It is an endemic subspecies on its way to becoming a species in a completely landlocked lake environment. The Saimaa ringed seal is a genetically, morphologically and ecologically distinct subspecies from close relatives the Baltic (Phoca hispida botnica) and Ladoga ringed seals (Phoca hispida ladogensis). Genetically, the Saimaa ringed seal population is more uniform and lower in genetic diversity when compared to the Baltic and Ladoga ringed seal populations, which are genetically more similar. There are differences in the morphological features in the skulls, teeth and in the colour of the pelage among the subspecies.

The adaptation of the Saimaa ringed seal to the lake environment is also shown in the different behaviour, such as the solitariness of the individuals and adapting to different breeding and moulting habitats. In the current habitat, the ice-associated Saimaa ringed seals breed in subnivean lairs on shorelines of small islands and islets, since the pressure ridges the marine ringed seal tend to use do not exist in Lake Saimaa. The Saimaa ringed seal has also adapted to breeding in February during the coldest and most snowy time of the year in Lake Saimaa, earlier than the Arctic Ocean ringed seal (Pusa hispida hispida) population, of which the Baltic, Ladoga and Saimaa ringed seal have been separated in the beginning. The bare craggy shorelines offer good sites for snow to accumulate so that digging the subnivean lairs is possible. The Saimaa ringed seals’ moulting happens on haul-out rocks in the vicinity of island and islets in May-June, mainly solitarily; it also different than other ringed seals and earlier than the Arctic ringed seals.

Criterion (x): The Saimaa ringed seal, an endemic subspecies of the ringed seal, lives in freshwater, and its only habitat is the totally landlocked Lake Saimaa. The population of this mythical seal collapsed due to human-caused influences, and after extensive conservation efforts, the population is recovering. Being one of the most endangered seals in the world, this subspecies has a high nature conservation value on itself, but also tells a successful story of conservation and scientific work. The isolated habitat provides a great place for scientific studies, the well-monitored Saimaa ringed seal population works as an indicator species, and the conservation aims developed in Lake Saimaa could assist other vulnerable seals around the arctic as climate change proceeds. Only in-situ conservation is possible since efforts in ex-situ conservation on these seals have not been functional.

The Saimaa ringed seal has an important role in the ecosystem due to its high trophic level and works as an umbrella species in Lake Saimaa. The protection of the seal also helps other species living in the lake. The lake and its islands provide habitat for a large amount of species living in the water and forest ecosystems. There are also several relict species, such as two species of fish: endangered populations of freshwater salmon (Salmo salar m. sebago) and arctic char (Salvelinus alpinus). Other relict species living in Lake Saimaa are the fourhorn sculpin (Myoxocephalus quardicornis), crustacean (Mysis relicta), and amphipod species (Monoporeia affinis, Pallasea Quadrispinosa and Gammaraganhus lacustris).

Statements of authenticity and/or integrity

The planned natural heritage property includes most of the distribution area of the Saimaa ringed seal and is sufficient in size to maintain critical ecological processes and to protect key features of the nature heritage at this site. The area is coherent, well managed and monitored. The lake has a good overall condition and clean waters. The property has a formal protection status by a large Natura 2000 network in Lake Saimaa, also containing the Linnansaari and Kolovesi National Park areas and national Nature Conservation Areas, which together maintain the special and sustainable living environment for the Saimaa ringed seal. Protection includes the most important breeding areas and areas where the increasing seal population is slowly returning after the previous local extinctions. The Natura 2000 areas create a national serial site of natural heritage, since not all of the Natura 2000 areas are connected to one another. In the gap between the two main breeding areas, there is a plan for a National Urban Park (based on the Land Use and Building Act 132/1999) to increase protection in the area.

State-owned parts of the Natura 2000 areas, on which the planned property is based, are managed by Metsähallitus, Parks & Wildlife Finland. The Centres for Economic Development, Transport and the Environment (ELY Centres) have the responsibility of following the protection aims fulfilment of the whole Natura 2000 network. In Lake Saimaa, where the Saimaa ringed seal is the basis of protection of Natura areas, the protection is mostly implemented based on the Nature Conservation Act (1096/1996) and other legislation, such as the Land Use and Building Act (132/1999), Water Act (587/2011), Forest Act (1093/1996), Fishing Act (379/2015) and Water Traffic Act (782/2019), depending on the concerned area. Weakening of the living environment of species that are the basis of protection in the Natura areas (Natura Conservation Act, 64a §) is forbidden. Some of the Natura areas, like National Parks and other Nature Conservation Areas, have their own specific integrated management plans. Otherwise, all Natura areas have the conservation status assessment of the species and habitat types, and in this plan, the protection aims are targeted and the condition is monitored. The general management plan to connect all these site-specific management plans covering the whole planned natural heritage site will be created during the application process.

The conservation history of the Saimaa ringed seal began in the 1950s, when the seal was protected, and hunting was prohibited by a decree in 1955. The population had collapsed mainly due to bounty hunting, environment pollution, by-catch mortality and wintertime fluctuation in water levels because the rationing caused harm for the breeding. The Saimaa ringed seal was one of the first subspecies of seals to receive the IUCN Red List status in 1966. At the European Commission level, the Saimaa ringed seal is under protection of the Habitat Directive (Council Directive 92/42/EEC,) and is a priority species in Annexes II and IV. Annex II states that, for the protection of the species mentioned, the specific conservation areas must be addressed (Natura 2000 areas). Annex IV protects the breeding and resting sites of endangered species in the whole distribution area, not only in the conservation areas. Moreover, the EU Water Framework Directive (2000/60/EC) orders for the protection of clean waters, the cleaning of polluted water areas, and to maintain the overall good status of waters.

In the national legislation the winter lairs and haul-out sites of the Saimaa ringed seal are protected by the Nature Conservation Act (1096/1996). In addition, Lake Saimaa is also protected by national laws, such as the Nature Conservation Act (1096/1996), Environmental Protection Act (527/2014) and Environmental Impact Assessment (252/2017). In 2019, all the municipalities, regional councils and ELY-centres in the area have signed the agreement to keep Lake Saimaa clean and protect it. Lake Saimaa is included in the Vuoksi River area´s water management plan made by the local ELY Centre. In Finland, the land use planning and construction is restricted by the Act (132/1999) also to advance the protection of the biodiversity and other nature values. Moreover, the Finnish National Shoreline Conservation Programme helps to protect the habitats of the Saimaa ringed seals.

There is no other seal population living and breeding so close to humans than the Saimaa ringed seal. The area of Lake Saimaa contains many holiday cottages (~70 000) and has six middle-sized cities (< 20 000 inhabitants) on its coast. However, in addition to the conservation areas, human use and influence are regulated in the whole area. The dangerous fishing gear regulations apply year-round and most harmful fishing nets are prohibited (degree 259/2016) in the whole distribution area during springtime when seal pups are in the most vulnerable stage of their life. The water level fluctuation issue that caused the subnivean lairs to collapse has been reacted by regulation of the outflow from the lake (Act 1331/1991). Aiming for the conservation of the Saimaa ringed seal, all the stakeholders, such as national and regional authorities, municipalities, universities and non-governmental organisations have agreed on the conservation aims and areas of responsibility in the national Conservation Strategy and Action Plan of Saimaa ringed seal (2017). An updated plan will be made for the year 2022. The seal population is monitored annually by Metsähallitus, Parks & Wildlife Finland. All of these regulations and aims together contribute to the conservation of the property’s Outstanding Universal Values.

The main threats facing the Saimaa ringed seal are the fishing activities that cause the by-catch mortality for the seals, together with climate change, which affects negatively the breeding habitat and survival of the pups. Lake Saimaa has multiple water basins with long distances from each other leading to isolation of the subpopulations, increasing the threat for local stochastic extinction, which together with the low genetic diversity is alerting. In some areas, the destruction of suitable sites for breeding causes harm (one-third of the lake’s shorelines are already unsuitable for successful breeding) and human-caused disturbance must be acknowledged. The environmental toxins (e.g. mercury) might cause issues in the future since the flows to the lake might be changing due to climate change. In addition, the predation of seal pups might grow through lack of the protection of subnivean lairs. Other possible risks in Lake Saimaa are caused by possible mining industry and the possibility of an oil accident caused by water traffic.

These threats have been addressed in several manners. Due to the by-catch mortality, there are the fishing regulations. To minimise the causes of climate change, the decreased breeding success has been addressed by developing man-made snowdrifts and artificial lairs, along with all of the conservation actions to grow the population. The translocation of the seal was done earlier, and it is now planned to save the genetic diversity and to decrease the possible stochastic extinction of subpopulations. In addition, there are regulations close to the breeding sites, the conservation areas are valuable and the environmental toxins have been monitored. The Mining Act of Finland will be soon be updated, and the possibility of any oil accidents has been prepared for by emergency services and volunteers. The position of the deep channel in the central Saimaa ringed seal habitat has been changed to increase the shipping security. Moreover, the amount of seal tourism is growing, and adequate tourism management plans and certification of the guides will be an important tool in the future for the long-term conservation.

Comparison with other similar properties

This property is an extraordinary habitat of the landlocked Saimaa ringed seal population. It is the most endangered ringed seal and one of the most endangered seals in the world, together with the Ungava seal population (Phoca vitulina mellonae) and Mediterranean monk seal (Monachus monachus). As you see, freshwater seals like the Saimaa ringed seal are very rare. There are only four other seal subspecies or species living in a similar kind of freshwater habitat, all in the northern hemisphere: the Baikal seal (Pusa sibirica), Ladoga ringed seal, North Pacific Harbor Seal (Phoca vitulina ssp. richardii) and Ungava seal. However, how strictly the seals are landlocked in the freshwater ecosystems varies among these species.

Lake Saimaa varies as a habitat from the other seal lakes through its totally landlocked, fragmented landscape with a long coastal line, which together with the distances inside the lake create geographically subdivided subpopulations to different water basins within the lake. The Saimaa ringed seal differs especially in its behaviour, as it is a solitary species. The other seal species tend to haul-out and even breed in crowds. The solitariness of the Saimaa ringed seal most likely is an adaptation to the fragmented habitat and the low population number. The Saimaa ringed seals have a high site fidelity and it haul-out on rocks for moulting; it breeds and rests mostly alone during the winter in subnivean lairs. This behaviour is extraordinary when comparing to the other seal species mentioned.

Lake Baikal, which is a UNESCO Natural Heritage Site nomination in Russia, is based on natural criteria (vii, viii, ix, x). Even though it is a lake system like Lake Saimaa, and habituated by a seal species, the landscape, living environment and evolution of species are totally different. Lake Baikal is the deepest and one of the oldest lakes, about 25-30 million years old. The Baikal seal status is Least Concern and its population of around 80 000-100 000 individuals is close to the carrying capacity of Lake Baikal. These seals are sometimes met in the Angara river, but connection to the ocean is far, so the Baikal seal is also considered an endemic landlocked species. The Baikal seal belongs to a different taxonomical group than ringed seals, more closely related to harbour seal and grey seal. The behaviour of Baikal seals differs from Saimaa ringed seals, and being more social animals, during the open water season, they might gather even 1 000 seals groups for moulting.

The Ladoga ringed seal in Russia has evolved partly in a similar fashion to the Saimaa ringed seal. Both subspecies became isolated from the marine Arctic and Baltic ringed seal populations after the last ice age, almost simultaneously over 9 000 years ago, and developed into their own subspecies during the last thousands of years. Lake Ladoga could be in the future transnational serial nomination, together with Lake Saimaa, to form a freshwater seal lakes heritage site. However, there are many differences between the Saimaa and Ladoga ringed seals. The Ladoga ringed seal growing population is estimated to be around 6 000-9 000 seals, and the population status is Vulnerable. The environment and the seals’ behaviour in Lake Ladoga is similar to their relatives living in oceans. Lake Ladoga has only 500 islands and is more uniform, larger and on average deeper, so it is a very different habitat from Lake Saimaa. The Ladoga ringed seal also has morphological differences and especially in their behaviour when comparing these two ringed seal subspecies. The colours of the pelage in adults and pups and skull and teeth morphology vary. The Ladoga ringed seal is the smallest among the subspecies. It is more social, uses actively varied kind vocalisation, forms larger herds during the open water season and shares the subnivean lairs, unlike their relatives in Lake Saimaa. Only part of the Ladoga ringed seal population breeds in subnivean lairs in the vicinity of islands and islets; they also use pack ice areas in the southern part of Lake Ladoga where it does exist. The seals’ movement from Lake Ladoga to the Baltic Sea through the river has been observed, but transition is minor.

There are two harbour seal populations that are both located in remote lake systems, which have not been widely studied. The harbour seal is a widespread species and high in number globally. Harbour seals are more gregarious and not a snow- and ice-associated species like the ringed seal is; they need open water in their living environment also in the winter since they cannot maintain breeding holes. The The North Pacific Harbour Seal inhabits the remote Lake Iliamna in Alaska, and it has been suggested that the population is the distinct population of the Pacific harbour seal. The population in the uniform lake is estimated to be around 400 individuals (no assessment of the conservation status). The evaluation is that if the seal is a distinct population of marine relatives it would have been founded only 200-5 000 years ago. There is a lack of information on these seals’ year-round behaviour. There is some suggestion that the seals move in and out of the lake through the river and that there might be seasonal movement. In that case, this seal is not landlocked, but does also inhabit a freshwater environment.

The other harbour seal, the Ungava seal, is the endangered subspecies living in the remote lake Lacs des Loups Marins in Canada. The subspecies has been studied little, and a very small population is suggested to be only around 100 individuals, but estimates vary between 50 to 600. This seal also lives in the fragmented freshwater lake system and is endemic. It has been estimated to be isolated around 3 000-8 000 years ago and has been announced to be their own subspecies. There have been some suggestions earlier that these seals move between the ocean and lakes, but the latest results support the theory of being the distinct subspecies. The harbour seals’ future in both lakes is hampered by mining exploration and development, occasional hunting and results of climate change. The habitat of the Ungava seal is also in danger by power plant plans in the seals’ potential distribution area that could change the water flows, ice situations and therefore also the amount of open water in the lakes. Most of the habitat in Seal Lakes was recently covered by the Tursujuq National Park, which increases the protection.

As shown, the Saimaa ringed seal as an endangered species has been widely studied, working as an example of a climate-change-affected mammal species in a cold environment and of successful protection and conservation efforts. The closed and well-monitored Lake Saimaa provides interesting insights to changes in the population, trends and adaption responses to climate change. Climate change causes changes in all freshwater seal species’ habitats and in all arctic seals. The Saimaa ringed seal is a good indicator species as it is the longest-monitored pinniped since the 1980´s with very precise details (e.g. number of pups born and breeding sites annually, mortality and causes of deaths and also skull- and tissue bank for over 40 years and newer sampling through genetics and photo-identification). It offers a clear study platform from the already well-known mammal species.

The story of the Saimaa ringed seal shows how remarkable conservation actions can be, as the population can be helped to grow even during challenging times. The population growth from 400 individuals and even more accurate monitoring is still the aim. The new population monitoring tools, such as camera trapping, mark-recapture, photo-identification and placenta collection in underwater surveys, have been adapted, and also new conservation actions, such as man-made snowdrifts, artificial lairs and the portable care corral for sick seals, have been developed for the protection of the Saimaa ringed seal. In the Lake Saimaa area, there is a long history with spreading knowledge of the seal and influencing attitudes towards them (e.g. campaigns, Nature Centres, school and event tours). The Saimaa ringed seal has a high value as a symbol of nature conservation in Finland. Moreover, the live webcam “Norppalive” has expanded information and positive attitudes of this rare species worldwide in the last five years with great success. These developed conservation aims can aid more widely vulnerable arctic species’ protection work.