Średniowieczna wiersza z rejonu mostu zachodniego na Ostrowie Lednickim

In the 2015 season, the underwater research in Lake Lednica focused on further exploration of two exploration plots of the Poznań bridge — 7 in the XCV area and 5 in the XCIII area and on the opening of a trial trench in the area of Ostrów Lednicki island. During the exploration of plot 5 in the XCIII zone, the wicker object in a radiating out shape was localised. Because of its archaeological value and the need of further exploration, the object was excavated and handed over to the Museum of the First Piasts at Lednica for preservation. The excavated object is probably a trap, a type of fish trap called ‘wiersza’ (a wicker fish trap). During examination of the object and cleaning after excavation, a great number of animal bone remains were collected and analysed. They almost exclusively came from fishes. In the bone material, the remains of several fishes were found: a catfish, eight perches, a pike, the fishes of the Cyprinidae family, including at least two roaches, as well as three remains of a pig. In the case of a catfish and the perches there were elements from all parts of the skeletons, while several bones belonged to two roaches and there was one pike tooth. The latter element was probably included in the assemblage accidentally. The conducted analysis shows that the catfish with SL (standard length) 70–75 cm and the perches, in most cases the large ones with SL=35–45 cm, were trapped in the fish trap. It is, however, not certain whether the roaches caught in the trap or had earlier been caught by predatory fish or fishes found in the trap. It is suspected that a phalanx and two ribs of a young pig, which probably come from the same animal, are the remains of a fishing bait placed in the wicker fish trap. Radiocarbon dating of the organic material which the object was made of indicates that it was placed after the bridge was no longer in use, probably in the late 12th or the early 13th century. For unspecified reasons the described wicker fish trap was not emptied and was left among the relics of the early medieval bridge. The discovery of the remains of the wicker fish trap and the analysis of its contents brought new information about one of the ways of fish harvesting used by the inhabitants of the area of Lake Lednica and its efficiency.