The Effect of Dust Transport on the Concentration of Chlorophyll-A in the Surface Layer of the Black Sea

Alla V Varenik,Darya V Kalinskaya

doi:10.3390/app11104692

Abstract

This paper focuses on the atmospheric dust transport effect on the changes in chlorophyll-A concentration in the Black Sea surface layer. In order to assess the input of nutrients with atmospheric precipitations at the Crimean coast of the Black Sea, the collected samples were analyzed for the content of inorganic nitrogen, phosphates, and silicon. The samples were taken into a wet-only sampler and into a permanently open one, to assess the effect of dust on the nutrients concentration in dry depositions. Cases of multi-fold excess of the nutrients content in the open sampler collected precipitation over that in the wet-only sampler were identified. For such high concentration cases, the 7-day back-trajectories analyses was carried out using the model of the international network AERONET and the HYSPLIT model. The results of our research showed that the influx of nutrients with the atmospheric depositions can result in increasing of chlorophyll-A concentration in 11–36% in the surface layer of the Black Sea. After atmospheric depositions, concentration of phosphates in the surface layer can increase more than five times compared with the background concentration. The increase of silicon concentration can reach 30%. The influx of atmospheric precipitation containing significant amounts of nutrients into the bay can shifts the Redfield ratio compared with background value up to three times.

Highlights

One of the most important aspects of rational nature management is the study of the state of the sea and ocean ecosystems [1]
We considered the dates in different years and seasons during the study period with the greatest difference in the nutrients concentrations in the open and closed samplers, as well as for those precipitation samples in which the nutrients concentrations were much higher than the volume-weighted mean (VWM) concentration
After atmospheric depositions concentration of phosphates in the surface layer of the Sevastopol Bay can increase more than five times compared with background concentration

Summary

Introduction

One of the most important aspects of rational nature management is the study of the state of the sea and ocean ecosystems [1]. North African deserts are an important source of mineral dust in the atmosphere [2]. This dust can be transported over thousands of kilometers to other continents and after deposition can affect oceanic and land biogeochemical cycles, even in very remote places. The influx of atmospheric precipitation containing significant amounts of nutrients influx atmospheric containing of nutrients into The the bay canoflargely shift theprecipitation Redfield ratio. This shiftsignificant may reachamounts three times compared into bay can largely shift the Redfield ratio.

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Discussion

Conclusion