Abstract

Ascidians are particularly vulnerable to hazardous accumulation of heavy metals in the marine ecosystem. Specimen of Ciona intestinalis were collected from three localities of the Mediterranean Sea of Alexandria in July 2009. Animals were dissected and frozen at -20°C. RAPD–PCR analysis showed natural differences or polymorphism among individuals of Ciona intestinalis, so investigations upon the effect of pollution on DNA level was not possible, where DNA was similar between individual samples. Genomic DNA was screened for damage using five primers. Only two primers gave fragments, suggesting very little genetic variation and extensive genetic exchange. Copper, iron, magnesium, cadmium, zinc and tributyl tin (TBT) accumulations were measured three times in both sea water and in the tissues of Ciona intestinalis using the atomic absorption spectrophotometer. The levels of lipid peroxidation, superoxide dismutase, catalase, glutathione transferase, glutathione reductase, aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase as well as proteins were recorded as well. This study concluded that the Western harbour (Abu Kir) of Alexandria is the most polluted study area and that heavy metals accumulate in the tissues of the ascidian Ciona intestinalis which enters the food chain, and finally reaches man.

Key words: hazardous accumulation, marine ecosystem, RAPD, PCR analysis, heavy metals, Ciona intestinalis, biomonitor.

Abbreviation

ALP, Alkaline phosphatase; AST, aspartate aminotransferase;GSH, glutathione reductase; GST, glutathione transferase; CAT, level of catalase.