engleski

Mucilage Risk Area Prediction by Biological Signatures and the Role of Changing Climatic and Oceanographic Conditions

In recent years massive mucilage events have occurred with increasing frequency in the northern Adriatic Sea with negative economic effects on fishing and tourism and harmful consequences for marine organisms. While the reasons why mucilaginous aggregates form is still a topic of debate, we have found that higher sea temperatures and changing patterns and variability of riverine freshwater input over the past 40 years, as a proxy for changing climate, can modify the thermohaline circulation of the northern Adriatic Sea with the generation of semi-closed circulation cells that increases residence time of entrained waters. It is in these cells that nutrients can accumulate and support strong growth of phytoplankton biomass. The eventual decay of this biomass, coupled with reduced water mass mixing, provide ideal conditions for the generation of mucilage. Ultimately, reduced oxygen replenishment in these cells may cause hypoxic or anoxic conditions. As a precursor to mucilage, transparent exopolymer particles (TEP) have been found to provide a fingerprint signature for identifying areas where the potential for mucilage formation is high. The spatial distribution of TEP matches hydrographic maps showing semi-enclosed circulation cells and may be useful for predicting areas which are at risk from mucilage events.

Adriatic; Mucilage; Circulation; TEP; Biological signature

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