Mussel power - fit for monitoring Kiwi coastlines
1 November 2012
A University of Canterbury PhD student has discovered that mussels are an effective marine organism to monitor coastal metal pollution in New Zealand.
Green-lipped mussels are ecologically, culturally and economically important, but are also among the most sensitive coastal organisms that have been tested, at least in terms of their response to the toxic metal, cadmium, UC biological sciences researcher Rathishri Chandurvelan said.
Mussels are sedentary, widespread and as filter feeders are constantly "sampling" the surrounding environment, she said.
"Cadmium can be found at high levels in New Zealand waters, usually a consequence of natural geological enrichment, but also as a function of industrial or agricultural contamination.
"I used an integrated laboratory and field approach to assess the effects of metals on mussels by examining a number of cellular, biochemical and physiological pathways that were impacted by cadmium exposure.
"We found that these mussels survive exposure to a highly toxic metal such as cadmium, which has no known biological functions. Field mussels were collected from Canterbury, the West Coast and Nelson regions during my three year research.
"A number of metals were measured in mussel tissues and in the environment samples. We found that some of the 'clean' sites we had chosen turned out to be contaminated. Some sites in Canterbury which we thought were clean were found to be contaminated with zinc, lead and arsenic. We believe contamination occurred after the earthquakes.
"We don’t know the source. It could be from a broken sewer pipe or it could be from the disturbance of the sea floor during the earthquakes."
The data Chandurvelan collected showed that the New Zealand green-lipped mussels were sensitive enough to respond to the presence of metals in the environment, but strong enough to tolerate exposure to such toxic metals.
"This makes NZ green-lipped mussels an ideal candidate for coastal bio-monitoring purposes. Future work may involve transplanting some mussels to monitor certain areas."
The UC project was funded by the Brian Mason Scientific and Technical Trust.
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Communications and External Relations
University of Canterbury
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