The Influence of Danube River Hydrographic and Thermic Factors on Fish Stocks Dynamics in Razim-Sinoe Lagoon System

Abstract

The Romanian fishing areas extends over 7000 km2 and 50% of the numbers of authorised fishers conduct their activities in the Danube areas. Inland fisheries are highly important for income, food security and nutrition. Inland peri-rural fisheries face degradation due to climate change. According to the European Commission, the dominant factor driving the change in water resources in Danube River basin is climate change. Global mean surface temperatures have increased, fact which causes a constant increase in water temperature as well. Razim-Sinoie Lagoon System represents the largest lagoon (1145 km2) in Romania and stands out for its ecological, historical and socioeconomic importance. The lagoon is connected to Danube River through the channels Dranov and Dunăvăț and receives significant river intake. This present study points out the vulnerability of fish stocks and Romanian fisheries in the context of climate change and global warming. Thus, the aim is to evaluate the influence of multiannual hydrographic and thermic regime on fish stocks status and structure from Razim-Sinoe Logoon System, between the years 2016-2018. Thus, a strong positive correlation was observed between the water temperature and the total quantity of fish catches. In case of fish stocks, a simultaneous decline of ichthyophagous fish species, while increasing the stocks of non- ichthyophagous fish species, is recorded. It is recommended that similar studies to be conducted also in other areas connected to Danube River hydrographic basin, in order to evaluate the magnitude of climate change and global warming impact on fish stocks status and structure.