Pollutants from oil spills, shipping activities and industrial effluents could be the reason for genetic damage in snails of Goa, research has found. The extent of genetic damage in snails could serve as a measure of the health of a marine ecosystem, it says.
A team of researchers collected snails of the species Morula granulata from nine locations along the coast of Goa – a major tourism and seafood industry hotspot of India. The team learnt that the extent of damage in the genetic material (DNA) of these snails increased with rising levels of toxic pollutants along the coast.
“When toxic contaminants, such as polycyclic aromatic hydrocarbons (PAHs), are taken up by marine organisms, the snails will try to metabolize the contaminants for subsequent elimination. The toxins are degraded, ultimately converted into by-products and removed from the body,” explains A. Sarkar, lead author of the study at Global Enviro-Care, Goa. “But during their metabolism, reactive intermediate stages are formed, resulting in DNA strand breaks.”
Sarkar and co-workers used molecular biomarker techniques to assess breaks in the DNA isolated from snails and determined its integrity. They observed that DNA integrity reduced by as much as 56% at one of the most polluted of the chosen sites (Hollant) compared to the non-polluted, reference site (Arambol) located farther away from the industrial belt. They found the concentration of PAHs in sediments to be highest around Hollant (5.17 μg/g) and lowest at Arambol (1.65 μg/g) among all sites.
Photo credit: A. Sarkar