Boundaries

The ecoregion includes the Kamchatka Peninsula south from the Voyamp’olka and Ozernaya rivers (ecoregion 612), and Komandorskiye Ostrova [Komandor] Islands. The northern border, from east to west, follows the divide between the Momlya River (a tributary of the Ozernaya River) and the northern reach of the Kamchatka River along the northern spurs of the Kumroch Range (Shiveluch Vulkano and Skalistaya Mountain). It then crosses the Sredinnyy Khrebet Range (at the northern slope of Shishel’ Mountain) north of the Tigil’ River Plain.

The northern Kuril Islands (north of Bussol Strait) also belong to this ecoregion. The largest islands from north to south are: Shumshu, Paramushir, Atlasova, Onekotan, Shiashkotan, Ketoy, and Simushir.

Topography

The topography of the ecoregion is diverse, and represents a typical volcanic landscape, with elevations reaching upward of 4500 m. Regular conic shape volcanoes or groups of volcanoes dominate the extensive elevated volcanic plateaus (the local name “doly”), which consist of lava and pyroclastic material. Volcanic highlands and ridges separated by a network of river valleys also occur.

The Kurils are also located within a tectonic and volcanic zone, which is characterized by a combination of young active volcanoes and adjacent deep oceanic hollows. The surface structure of the Kuril Islands is largely determined by ancient and recent volcanic activity connected with tectonic breaks. Often lakes are located in the craters of volcanoes. The northernmost island, Shumshu, is the only island with no mountains and many shallow vegetated lakes with marshy coasts.

Freshwater habitats

The hydrographic network of Kamchatka is directly related to orographic characteristics of the peninsula. Large sections of Kamchatka rivers have pronounced mountain characteristics. The longitudinal axis of mountain ranges favor hydrographic systems with relatively short extensions. The arrangement of these mountain ranges have also affected the direction of the largest rivers – Kamchatka, Bystraya, Kozyrevka, and Elovka. The lower parts of rivers are characterized by slow, calm flow, and a river bed that is split into anabranches with abundant spits and islands. Even though plain rivers occur on the peninsula, they are of secondary importance. The main watershed of the peninsula is the Sredinnyi Range. The largest rivers of the east coast are Kamchatka (719 km, catchment area is 56,400 km²), Avacha, Paratunka, Zhupanova, Shchapina, and Bolshaya Khapitsa. Throughout most of its length the Kamchatka River has a relatively wide, pronounced floodplain and developed valley; only in separate areas do offshoots of the mountain range approach the river mouth. Further downstream the river valley expands, with numerous lakes appearing during floods as well as a number of lowland swampy shores. The majority of rivers are less than 100 km in length. The largest rivers of western Kamchatka are Tigil (the second largest river of the peninsula), Bolshaya, Krutogorova, Icha, Sopochnaya, Moroshechnaya, Belogolovaya, Khairyuzova, Voyampolka, Palana, Amanina, and Lesnaya.

Lakes of Kamchatka are diverse in size and origin. They can be divided into the following types by the origin of their hollows: 1) volcanic (caldera, crater, lava pits); 2) tectonic (faulting); 3) marine (lagoon, bay origin); 4) glacial (tarn, dam lakes glacial-accumulative relief); 5) erosion-riverine and accumulation-riverine (floodplain and delta); and 6) peat.

Lake hollows of volcanic origin are situated mainly in recent volcanic regions and partly in the Sredinny Range. Even Lake Kuril’skoye (306 m), the deepest lake of Kamchatka, is considered volcanic even though its bottom is below sea level. Lakes are present in craters and calderas of many extinct volcanoes and some active volcanoes (Klyuchevoye and Shtyubel in the caldera of Ksudach Volcano; Kenkuzhen and Khangar, in the calderas of the volcanoes Bakening and Khangar; boiling and hot lakes in the caldera of Uzon). Their shape is rounded in the majority of cases.

Some lakes were formed as a result of barraging of rivers by lava streams. They include, for example, the Palanskoye Lake in the Sredinnyi Range. Possibly other large lakes are of the same origin (e.g. Glubokoye, Kamenistoye, Mezhdusopochnoye, Bolshoye). Barrage lakes are characterized by their peculiar lobed shape.

Lakes of marine origin are spread along the coasts of Kamchatka. They formed as a result of isolation from the sea by sand pebble spits of shallow bays and bights that cut deeply inland. These include the largest lake of Kamchatka – Lake Nerpich’ye – and also lakes Bolshoi Kalygir, Listvenichnoye, etc. All of them are shallow. The average depth of Lake Nerpich’ye (with an area of 500 km²) is 4.4 m, and its maximum depth is 12 m. Some of them are saltwater as a result of the dripping of marine water.

Lagoon lakes form in river mouths when they are isolated by a swell developed by storm waves. River waters dammed by the swell overflow, forming elongated lotic lagoon lakes that stretch along the coast for long distances. The water level of the lakes is slightly above sea level. The river frequently breaks through the beach ridge and the lake decreases in size or disappears completely. Lagoon lakes are particularly numerous along the coast of the Western Kamchatka Plain.

Floodplain lakes and delta lakes are widespread in valleys of the lower reaches of the Kamchatka and Yelovka rivers.

Lakes of glacier origin – tarns and lakes of glacier accumulative relief – are most developed in the Sredinnyi Range. Lakes of glacier accumulative relief are most widespread, and form a typical lake landscape in some places along the western and eastern foothills of the Sredinnyi Range.

In Kamchatka there are lake depressions and depressions of tectonic (overflow) origin. These are lakes with rectilinear steep banks situated in deep ravines. The maximum depth of one of such lake, Lake Dalneye (near Petropavlovsk), is 60 m, with a length of 2.5 m and width of 0.5 km. Its bottom is situated below sea level. The depression of Lake Azabach’ye is also probably of tectonic origin, and is characterized by notable depths (33 m).

Peat lakes are the most numerous group of lakes. They form accumulations on extensive peat bogs of the Western Kamchatka Plain and maritime plains of eastern Kamchatka.

Ice and flood regimes vary among Kamchatka\'s rivers. Because of peculiar climatic conditions and the abundance of hot springs, many rivers of southern and middle Kamchatka freeze and break up several times, and some do not freeze at all. The majority of rivers begin to freeze-over in November and even in December. Kamchatka lakes lie at different altitudes above sea level and vary in temperature and the timing of freezing and breaking. The water level in lakes along the coasts of Kamchatka depends also on set-up and set-down of sea currents and also on tidal sea currents. The greatest range of water level fluctuations in lagoons on the western coast reaches 4-5 m. The freezing of lagoons and lakes on marine coasts frequently occurs in December – early January, i. e. later than lakes situated inland. However, strong ice cover forms mostly on lakes in northern Kamchatka and in mountain regions; in the southern peninsula the ice regime of lakes and rivers is inconsistent.

Water bodies of the northern Kurils represent a wide variety of relatively small streams and lakes that are connected to the sea. Some of them are influenced by volcanic activity.

Terrestrial habitats

This ecoregion includes only three terrestrial ecoregions: Kamchatka-Kurile meadows and sparse forests, Kamchatka Mountain tundra and forest tundra, and Kamchatka-Kurile taiga.

Description of endemic fishes

White char (Salvelinus albus) is located in Lake Azabach’ye (type habitat), Kamchatka River drainage, Lake Kronotskoye, Kronotskaya River drainage, and southeastern (Pacific) coast of Kamchatka. In Lake Kronotskoye it is only represented by a lake form. Small chars live close to coasts, and less frequently in open spaces in the upper water layers. Large chars live far from coasts during summer, approaching the coast in autumn. The species migrates in the lake in schools, from several dozens to hundreds of individuals.

Salvelinus krogiusae is a freshwater lake species, only known from Lake Dalneye in the drainage of the Paratunka River in southeastern Kamchatka. Its abundance is low, apparently limited by the availability of suitable spawning areas.

Salvelinus kronocius is found in Lake Kronotskoye (type locality), the Kronotskaya River drainage along the southeastern (Pacific) coast of Kamchatka. It has a narrow distribution range, and is protected in the Kronotsky Biosphere Reserve.

Salvelinus kuznetzovi is a freshwater lake species found in Lake Ushki in the Kamchatka River drainage. There is no data on this species.

Salvelinus schmidti is a species with few individuals that is close to the Pacific Salvelinus malma. It is found in the drainage of Lake Kronotskoye on the Kamchatka Peninsula. It leads a sedentary lifestyle in the open part of the lake and also in the coastal parts with sandy and small pebble bottoms. It does not migrate for long distances.

Salvelinus gritzenkoi (Onekotan Island) is considered here as a distinct species. However, it may represent a local lacustrine resident form of the Salvelinus malma complex.

According to Chereshnev (1998) Onchorhyncus penshinensis lives primarily along the coast of the Sea of Okhotsk in the South Kamchatka zoogeographic region in Russia. Its morphological and karyological differences and also zones of sympatry suggest differences between Onchorhyncus penshinensis and rainbow trout (Onchorhyncus mykiss) on species level (Chereshnev et al. 2002).

Other noteworthy fishes

Thymallus mertensii is the only primary freshwater fish widely distributed throughout the Kamchatka Peninsula. It is sedentary and does not go on extensive seasonal migrations. It prefers clean mountainous and semi-mountainous rivers, as well as large and small glacier and tectonic lakes. Its ecological optimum is in deep lakes and areas of rivers with slow currents, abundant food, and favorable water temperatures. It is abundant.

Ecological phenomena

Most rivers of Kamchatka support exclusively abundant sea runs of Pacific salmons, especially coho salmon (Oncorhynchus kisutch) and Chinook salmon (O. tshawytscha), which are relatively rare in other regions of Eurasia. Primary freshwater fishes are almost absent from the ecoregion.

Justification for delineation

The ecoregion is defined bythe southern part of the Kamchatka Peninsula and northern Kuril Islands. The endemism level is relatively high, although the recent fauna seems to be young and have originated from marine species. The poverty of true freshwater fauna is the most remarkable feature of the ecoregion. Native cypriniform species are completely absent.

Level of taxonomic exploration

Fair: the status and distribution of some Salvelinus and Onchorhyncus species need further studies, especially in comparison with other Eurasian and American taxa.