Climate-Driven Changes in the Black Sea in Front of the Bulgarian Coast

S. Dineva
Institute of Fish Resources, BG – 9000 Varna, Bulgaria

Abstract

Dineva, S., 2013. Climate-Driven Changes in the Black Sea in front of the Bulgarian Coast. Bulg. J. Agric. Sci., Supplement 1: 20–29

 

The world is heating up and assessment of the magnitude of temperature increases refers to the Earth’s seas and oceans. The seas and oceans act as a giant rechargeable battery for the Earth. It takes a lot of energy and time to change sea temperature so that seas and oceans can be called the ‘memory’ of the Earth’s climate system. The Black Sea in front of the Bulgarian coast becomes climate change affected area. Research in the 30-mile Black Sea zone in front of the Bulgarian coast, down to 100-m isobaths was done, with aim climate-driven changes to be established. In-situ measurements of temperature, salinity, oxygen and oxygen saturation were done. Processing of samples for nutrients was performed via unified methods for marine waters. Climate-driven transformation of the thermo-haline structure was ascertained. Because of warming, the Black Sea Cold Intermediate Layer in front of the Bulgarian coast was warmer in the frame of isotherms of 8˚C, with greatly elevated bottom border. Salinity was above the long-term average throughout the 100 m investigated layer. The greatly elevated Cold Intermediate Layer bottom border brought about rise of high-salinity deep waters. Owing to crucially reduced fresh water inputs, extremely low were the concentrations of nutrients. The organic nitrogen share was dominating at total nitrogen formation in the open-sea.

Key words: Black Sea, climate change impact, Danube River stream
Abbreviations: Cold Intermediate Layer (CIL); Cold Intermediate Water (CIW); Organic nitrogen (ON); Sea surface salinity (SSS); Sea surface temperature (SST); Total inorganic nitrogen (TIN); Total nitrogen (TN)

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