Vida ®iliukiene
Institute of Ecology, Akademijos 2, 2600 Vilnius, Lithuania

Key words: the Curonian Lagoon, smelt, larvae, density, distribution, length, zooplankton, food, spawning

Abstract.
Smelt larvae were sampled twice a year either at the end of May or at the beginning of June and at the beginning of July from 1996 to 2000 in the Lithuanian part of the Curonian Lagoon. The share of smelt larvae in the ichthyoplankton of the Curonian Lagoon reached 18%, on average, at the end of May and at the beginning of June. Their density varied at different stations from 0 to 28.0 ind./m³. The highest smelt larva density was noted on June 3, 1997. At the end of May and the beginning of June, they mainly concentrated in the eastern part of the lagoon between Vente and Kintai (Fig. 1). At the beginning of July, smelt larvae were found only at several control stations, where their density did not exceed 0.2 ind./m³. A significant decrease in smelt larvae can be observed in the Curonian Lagoon during this month, as the majority of them have already migrated to the Baltic Sea. In 1998 the density of smelt larvae was lower at a depth of 0.5 m than at 1.5 m. Studies carried out repeatedly in 1999 did not confirm this tendency. Smelt larvae feed on zooplankton, mainly on copepods. However, correlation coefficients did not show a strong relationship between the density of smelt larvae and the biomass of zooplankton. At the end of May and at the beginning of June, the lengths of smelt larvae varied from 8.5 to 23.0 mm. At the beginning of July, the lengths of smelt larvae varied from 15.0 to 34.0 mm. The shortest mean length of smelt larvae was determined in 1996, while in 1998 it was the longest.