Fish community inventory

Commercially valuable fish species are inventoried quite well, however, the knowledge about protected species fish species in the Eastern Baltic Sea is very week. Therefore in the frame of this project separate action focusing on inventories of protected fish species are set up. The inventories are focussed on those species, which are threatened and are of highly conservation value in the European Community (listed in the Annex II of the Habitat Directive). This survey will give comprehensive and detailed information about the existence and abundance of these fish species.

The species that are interest of this project are following: Twaite shad (Alosa fallax), Asp (Aspius aspius), Spined loach (Cobitis taenia), Vendace (Coregonus albula), Common whitefish (Coregonus lavaretus), Sea lamprey (Petromyzon marinus), Bullhead (Cottus gobio), River lamprey (Lampetra fluviatilis), Mud loach (Misgurnus fossilis), Ziege (Pelecus cultratus), Snake blenny (Lumpenus lampetraeformis), Rock gunnel (Pholis gunnellus), Fourhorn sculpin (Triglopsis quadricornis), Shorthorn sculpin (Myoxocephalus scorpius), Longspined bullhead (Taurulus bubalis) and Striped seasnail (Liparis liparis).

To gain comparable information from all Baltic States the methodology of the inventories is agreed before starting the actual field works. The methods used for field investigations are – gill net fishing, hand seining and food analyses of the fish.
The nets for the gill net fishing are up to 30 m long and the height is 1.8 m but the used mesh sizes are different. The nets are placed in the sea with corks and weights that allows them to hang in a vertical position. Fish swimming into the mesh are caught in the web by their gills.
Hand seining is used now as one of the methods to describe the coastal fish communities, especially small-sized fish species and younger age classes of some species. However, the size of the hand seines is different in all countries.

The inventory of fish communities will be performed in the Eastern Baltic sea applying harmonized methodology. This will allow later to compare and process the results estimating a region as a whole gaining information on species distribution, abundance and concentration areas.
BEF Life Natura