Heavy metal assessment in algae, sediments and water from the Bulgarian Black Sea coast

Abstract

The aim of our investigation is a survey of heavy metal pollution in algae, sediments and water from the Bulgarian Black Sea coast and determination of algae species appropriate as bioindicators. The levels of iron, copper, manganese, zinc, lead and cadmium are determined in water, sediments and eight species of macroalgae: (four green: Cladofora laetevirens, Ulva rigida, Enteromorpha intestinalis and Bryopsis plumosa; two brown: Cystoseira crinita and Cystoseira barbata; and two red: Ceramium rubrum and Corallina mediterranium), widely distributed in the Bulgarian coastal zone, and dominant in the Black Sea. The studied area is the littoral coastal zone from four locations - Tuzlata, Ravda, Ahtopol and Sinemoretz. No significant variations between metal concentrations in algae samples are obtained, while for sediments and water there are significant differences between location and season. The Cladofora laetevirens and Ceramium rubrum species show the highest metal content while Cystoseira crinita and Cystoseira barbata show the lowest level. The correlation coefficients and concentration factors of the elements are calculated.