The effect of algal blooms on fish in their inshore nursery grounds in the Gulf of Gdańsk

Abstract

Studies of cyanobacterial bloom dynamics show that the highest biomass accumulation of Nodularia spumigena is observed in the shallowest area of the Gulf of Gdańsk in summer. In the same region and time, the highest fish abundance is observed. Mostly young individuals of gobies, small sandeel, flounder, three-spine stickleback and young herring occur. In this work we compare how toxic blooms of cyanobacteria influence the number and structure of fish communities in a coastal zone. The results obtained in our study were rather unexpected. More fish species were caught and the biomass of fish was higher during a bloom than in a month following the sampling (no bloom).

Spatial–Temporal Distribution of Fish Larvae in the Pearl River Estuary Based on Habitat Suitability Index Model

“…The higher Chl-a area did not result in a high distribution of larva density ( Figure 2 ), partly due to a lag in the influence of Chl-a, which was one of the important indicators of marine primary productivity in fishery resources [ 53 ]. In addition, the decrease in Chl-a in this area increased the transparency of seawater, which had a positive impact on the spawning activity of fish and contributed to the increase in the number of larvae [ 54 ].…”

Late Holocene Vistula River Floods Recorded in Grain Size Distributions and Diatom Assemblages of Marine Sediments of the Gulf of Gdańsk (Baltic Sea)

“…The waters are eutrophic (Niemkiewicz and Wrzołek, 1998;Szymczak-Żyła and Kowalewska, 2009;Leśniewska and Witak, 2011;Voss et al, 2011;Szymczak-Żyła et al, 2019) and with low visibility, which limits the photic zone up to a few meters (Łysiak-Pastuszak et al, 2004;Witak and Pędziński, 2018). Moreover, during summer periods cyanobacteria blooms were frequently observed in recent decades (Pawelec et al, 2018;Pliński et al, 2007).…”