Orestiada lake, or as it is most known, the lake of Kastoria, is a place of unique beauty and a very important area for breeding and wintering species of birds. It is the residue of a huge ancient lake of the Miocene epoch that reached an area of 164 sq.kilometres and had a depth of 50 metres. The lake is located in a basin surrounded by mountains at an altitude of 620 metres. It covers an area of 29.2 sq.km with a coastline that spreads to 34 km. The maximum depth of the lake reaches about 9 m. and the average depth is 4,5 m. In the northeast stands Vitsi mountain, in the northwest Triklario mountain and in the southwest start the foothills of Voio mountain. Orestiada is mainly renewed by the waters that descend from Vitsi through the Xeropotamos stream on the eastern shores, but also by other smaller streams, such as Aposkepos, Fountouκli, Istakos, Foteini, Metamorphosis, Toihos, Agios Athanasios and Vyssinia. The catchment area of the lake reaches 267 sq.k. Part of its waters are send to Aliakmonas river through the small Gioli stream to the south. To the west lies a peninsula, with the beautiful city of Kastoria built on its isthmus, that ends up on the hill called “mountain” of Kastoria. This peninsula gives the lake its characteristic kidney shape. Almost every winter some parts of Orestiada freezes for 2 to 5 weeks. On the southern shores of the lake lies Dispilio, where the remains of an important Neolithic lakeside settlement have been found. Orestiada is surrounded by wooded hills, wet meadows, reeds, lakeside forests, marshes and fields, all habitats that sustain a rich fauna. It is an eutrophic lake, due to agricultural waste and chronic pollution from urban waste water from the city, which, fortunately, has now stopped. For years, there has been a decrease in the level of the lake from the silt materials from Xeropotamos. The deposit is so large that it tends, after many years, to split the lake in two. The exploration of wildlife in Orestiada lake is enjoyable as it is combined with the tour in one of the most beautiful cities in Greece.
In the northwest stretches a lakeside forest of willows, poplars and common alders, in the east and in the south there are seasonal wet meadows and almost in all the perimeter grow reed beds. The trees around the lake are mainly oriental plane trees with the vegetation complemented by elms, cornelian cherries, blueberries and wild rose bushes. Of the aquatic plants here are found species like Trapa natans, Najas marina subsp. major, Stuckenia pectinata, Potamogeton crispus, Potamogeton natans, Potamogeton perfoliatus, Potamogeton lucens, Azolla filiculoides, Ceratophyllum demersum, Ceratophyllum submersum, Persicaria amphibia, Myriophyllum spicatum, Nymphaea alba, Nuphar lutea, Hydrocharis morsus-ranae, Lemna gibba and Spirodela polyrhiza. The flora around the lake and on the peninsula includes rare and beautiful species such as Lilium candidum, Galeopsis ladanum, Iris pseudacorus, Stachys palustris, Leucojum aestivum subsp. aestivum, Delphinium balcanicum and Butomus umbellatus. It is important that in the surrounding hills grows the rare Pulsatilla halleri subsp. rhodopaea. Other plants in the area are Centaurea graeca, Scutellaria galericulata, Paronychia macedonica subsp. macedonica, Campanula versicolor, Althaea officinalis, Verbascum flavidum, Clematis viticella, Alisma plantago-aquatica, Rorippa amphibia, Oenanthe aquatica, Eleocharis palustris, Lythrum salicaria, Galium palustre, Veronica anagallis-aquatica, Mentha aquatica, Nasturtium officinale, Sparganium erectum subsp. neglectum and Helosciadium nodiflorum.
Orestiada is a paradise for birds as here live 200 species of which 90 breed. The presence of dalmatian pelicans, white pelicans, greylag gooses and pygmy cormorants is important, while here is the biggest breeding place of mute swans in Greece. The predators include spotted eagles, lesser spotted eagles, short-toed eagles, marsh harriers, Montagu’s harriers, hen harriers, honey buzzards, common buzzards, sparrowhawks, levant sparrowhawks, kestrels, red-footed falcons, merlins, hobbies and peregrines. Night predators include eagle owls, long-eared owls, barn owls, tawny owls and little owls. The ducks here represented by rare goosanders, shelducks, teals, widgeons, gadwalls, mallards, garganeys, shovelers, common pochards, ferruginous ducks, goldeneyes and tufted ducks. The lake hosts all nine species of herons of Greece (bittern, little bittern, night heron, cattle egret, squacco heron, little egret, great egret, grey heron and purple heron). At the wet meadows and in the reeds live, among others, glossy ibises, water rails, spotted crakes, moorhens, black-winged stilts, avocets, lapwings, little ringed plovers, black-tailed godwits, ruffs, snipes, redshanks, greenshanks, sandpipers, wood sandpipers and marsh sandpipers. Of the terns here live common terns, black terns, white-winged black terns and whiskered terns. Other birds of the lake and the surrounding areas are great crested grebes, little grebes, black-necked grebes, cormorants, white storks, coots, turtledoves, cuckoos, nightjars, swifts, alpine swifts, kingfishers, bee-eaters, rollers, syrian woodpeckers, skylarks, house martins, swallows, red-rumped swallows, water pipits, tree pipits, wrens, dunnocks, nightingales, black redstarts, stonechats, song thrushes, mistle thrushes, fieldfares, Cetti’s warblers, fantail warblers, moustached warblers, reed warblers, great reed warblers, subalpine warblers, orphean warblers, lesser whitethroats, common whitethroats, goldcrests, spotted flycatchers, semicollared flycatchers, long-tailed tits, penduline tits, wood nuthatches, red-backed shrikes, lesser grey shrikes, jays, jackdaws, rooks, ravens, golden orioles, starlings, willow sparrows, tree sparrows, greenfinches, goldfinches, serins, siskins, linnets, reed buntings, rock buntings, cirl buntings and corn buntings.
Amphibians are represented by fire salamanders, greek newts, macedonian crested newts, common toads, greentoads, tree frogs, greek frogs, agile frogs and balkan frogs. The herpetofauna is rich and includes pond turtles, Hermann’s tortoises, greek slow worms, glass lizards, dalmatian algyroides, balkan green lizards, common green lizards, common wall lizards, balkan wall lizards, snake-eyed skinks, worm snakes, smooth snakes, large whip snakes, four-lined snakes, levant montpellier snakes, grass snakes, dice snakes, Dahl’s whip snakes, cat snakes, aesculapian snakes, leopard snakes and nose-horned vipers. There is a small number of otters in the lake and wolves still appear in the surrounding hills. It is impressive that often, especially during the winter, bears descend to the lake. Other mammals of the surrounding area are the wild cats, foxes, weasels, pine martens, badgers, red squirrels, forest dormouses, edible dormouses, wild boars, eastern hedgehogs and hares.
Orestiada has been one of the most important fishing centres of northern Greece for centuries. Today and after enrichments with alien species, the lake’s fish fauna includes 14 species. Of these the most important are the northern pike (Esox lucius), the aegean gudgeon (Gobio bulgaricus) and the wels catfish (Silurus glanis). Other fishes of Orestiada are the european eel (Anguilla anguilla), the common roach (Rutilus rutilus), the european rudd (Scardinius erythrophthalmus), the vardar chub (Squalius vardarensis), the european tench (Tinca tinca), the prussian carp (Carassius gibelio), the european carp (Cyprinus carpio), the grass carp (Ctenopharyngodon idella), the pumpkinseed (Lepomis gibbosus), the rainbow trout (Oncorhynchus mykiss) and the european perch (Perca fluviatilis). It is worth visiting the Aquarium of Kastoria, one of the largest aquariums in the Balkans, where you will see fishes and other organisms of the fresh waters of Greece.
(landscape photos: Hercules Milas)