Cormorants

The great cormorant (Phalacrocorax carbo), known as the great black cormorant across the Northern Hemisphere, the black cormorant in Australia, the large cormorant in India and the black shag further south in New Zealand, is a widespread member of the cormorant family of seabirds. The genus name is Latinised Ancient Greek, from φαλακρός (phalakros, "bald") and κόραξ (korax, "raven"), and carbo is Latin for "charcoal".

It breeds in much of the Old World and the Atlantic coast of North America.

There are two subspecies of cormorant in Sweden. The bird that for the most part breed in Sweden, both along the coast and inland, are P. c. Sinensis is sometimes called "mellanskarv". It nests along the west coast, south coast of Sweden and up the east coast and northern coast. It also breeds in the hinterland of lakes and wetlands. A large part of the Swedish breeding stock of P. c. Sinensis are migratory birds and wintering further south in Europe, the Mediterranean , but an increasing number have begun to overwinter in southern Sweden. The other subspecies present in Sweden, is the P. c. Carbo , which is essentially a winter guest both along the West Coast and in the Baltic Sea. It arrives in its winter quarters in Sweden in the autumn and stays until March-April. These wintering cormorants have their breeding grounds in Norway and northwestern Russia. It is uncertain if it also occurs on rare occasions in Bohuslän . The finding of fossil bones of this subspecies in settlements in Sweden indicates that it has previously been a breeding bird in Sweden.

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It is not rare to see in the archipelago island where vegetation has been almost entirely destroyed by the comorant dejections. These islands are colonised by comorants during the mating season. Up to 1000 bird can be found in a colony. However the amoniac will be transformed in nitrogen and will ensure that vegetation will grow again in the future on these island.