Current status of the Eastern Baltic cod population Gadus morhua callarias Linnaeus, 1758
- DOI
- 10.5922/gikbfu-2023-4-9
- Pages
- 115-124
Abstract
A review of scientific literature describing the state and dynamics of the Eastern Baltic cod population over the past 30 years has been conducted. The Eastern Baltic cod is one of the most important commercial species in the Baltic Sea. An ecological regime shift in the early 1990s, resulting from a reduction in the frequency of large North Sea inflows, led to a decrease in salinity and oxygen levels in the bottom layers of the deep basins of the Baltic Sea. This caused a sharp deterioration in the spawning conditions. Factors influencing the Eastern Baltic cod population and changes in the population under the influence of these factors are described. The decisive impact of North Sea inflows and their prolonged absence on the population's development, the influence of oxygen saturation levels on all life stages of cod, and the negative consequences of hypoxia for the feeding of Eastern Baltic cod are noted. Among the changes in the population, a decrease in the number of eggs in spawning areas during the peak spawning period, a reduction in the average individual sizes and weights of specimens, and a shift in the spawning peak to later dates are highlighted. The conclusion is drawn about the unsatisfactory state of the population and the impossibility of its recovery in the medium term, regardless of commercial catch rates.