Abundance and distribution of larval and early juvenile fish in Puck Lagoon and outer Puck Bay in the southern Baltic Sea

Puck Bay, regarded as a crucial region along the Polish coastline, has witnessed a decline in fish taxa diversity and abundance over the past several years. The objective of this study was to ascertain the abundance and geographical distribution of fish larvae in Puck Lagoon and outer Puck Bay over the period from April to the end of September. A neuston net with a 300-μm mesh was utilized at 10–15 stations situated in the shallow coastal waters of the study area. A total of 13 taxa were identified among the larvae captured. The majority of larvae observed during the entire study period were identified as Gobiidae. Furthermore, the most abundant taxa were three-spined stickleback, broad-nosed pipefish, straight-nosed pipefish, Ammodytidae, and sprat. The presence of larvae belonging to other taxa, including herring, flounder, cod, turbot, fourbeard rockling, and roach, was observed on a sporadic basis. Details such as Shanon’s diversity Index, the month of larval presence, geographical distribution, and differences in abundance and body size between Puck Lagoon and outer Puck Bay were recorded. The findings indicated that the study area was characterized by a limited diversity of fish taxa. Furthermore, the majority of these taxa (e.g., Gobiidae, broadnose and straight-nosed pipefishes) are not the subject of fishing activities. Nevertheless, they serve as a food source for other taxa and are integral to the ecological balance of the ecosystem. It can thus be concluded that Puck Lagoon and the outer Puck Bay constitute an important habitat for non-commercial and commercial fish taxa.