Species Disappeared from the Baltic Sea

Having the above mentioned limitations in mind, a first comparison of past and present species inventory of the Baltic can be made by the data provided by Nielsen et al. (1995). 

As can be seen in Table 16.1, only a few species are listed in this survey, which were not found after 1970, the border drawn between historic and recent records by Nielsen et al. (1995). 

In total, 48 out of the 422 species listed by Nielsen et al. (1995) have not been found after 1970. This does not mean, as stated already by Nielsen et al. (1995), that these species have disappeared as many of them are smaller ones that can be easily overlooked. 

But also in the case of larger organisms, it happens that species are overlooked. A group that was quite intensively investigated between 1998 and 2003 are the Charophytes, target of a Baltic-wide survey conducted by the WG 33 (covener I Blindow) of the Baltic Marine Biologists. 

During this survey, seven sites of occurrence of Chara braunii along the Finnish coast were found, and only at one of the six sites known to harbor this species before 1981, its occurrence was proven to be extinct (Zhakova, 2004). 

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