Assessment of sediment metal contamination in the Mar Menor coastal lagoon (SE Spain): Metal distribution, toxicity, bioaccumulation and benthic community structure

L Marín-Guirao,A Cesar,R Vita,A Marín

doi:10.7773/cm.v31i2.53

Abstract

The Mar Menor coastal lagoon is one of the largest of the Mediterranean Sea. Ancient mining activities in the mountains near its southern basin have resulted in metal contamination in the sediment. The metal bioavailability of these sediments was determined through laboratory toxicity bioassays using three Mediterranean sea urchin species and two amphipod species, and by means of field bioaccumulation measurements involving the seagrass Cymodocea nodosa. The effect of sediment metal contamination on benthic communities was assessed through benthic infaunal analyses, applying classical descriptive parameters and multivariate techniques. The sediments affected by the mining activities presented high levels of toxicity and metals were also accumulated in the seagrass tissues, pointing to metal bioavailability. Although the classical benthic indices were not clear indicators of disturbance, the multivariate techniques applied provided more consistent conclusions.

Highlights

IntroductionCoastal lagoons and estuaries are physicochemically unique because of their strong gradients in salinity, temperature, pH, dissolved oxygen, redox potential, sediment
IntroducciónCoastal lagoons and estuaries are physicochemically unique because of their strong gradients in salinity, temperature, pH, dissolved oxygen, redox potential, sedimentLas lagunas costeras y los estuarios son sistemas con características fisicoquímicas únicas debido a los fuertes gradientes de salinidad, temperatura, pH, oxígeno disuelto, potencialCiencias Marinas, Vol 31, No 2, 2005 chemistry and species composition
The results indicated toxicity moving from the sediments to the water column, with consequent adverse effects on sea urchin embryo development

Summary

Introduction

Coastal lagoons and estuaries are physicochemically unique because of their strong gradients in salinity, temperature, pH, dissolved oxygen, redox potential, sediment. Ciencias Marinas, Vol 31, No 2, 2005 chemistry and species composition. They can fundamentally be considered as receivers of sediments that act as a trap for materials. Specific toxicity and other environmental assessment methods for the sediments of lagoons or estuaries are few and relatively new, since many marine and fresh-water techniques are not generally applicable. Lagoons tend to have a low number of species and low species diversity compared with fresh or marine waters, and for this reason traditional univariate analyses of populations can be difficult to interpret in such naturally stressed environments. Ecological stress, from any source, is best measured using multivariate methods and analyses (Chapman and Wang, 2001)

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