Environment:The environment is constantly under threat from pollution and now of climate-driven changes, as seen in two impressive research projects at the BT Young Scientist & Technology Exhibition.
One shows that at least half the length of the Dodder river is significantly polluted and another suggests how tank-grown corals could one day be used to reseed reefs destroyed by climate change.
Fiachra Maguire (13), a second- year student at St Mary's College, Rathmines, Dublin spent three months tramping up and down the Dodder. His goal was to measure water quality but also to identify and count the worms, larvae and other creatures living in the river.
"It was a biological water assessment from the Dodder's source to its confluence. It is a detailed study of how clean the water is," explained Fiachra. It was the "actual water quality, not the visual quality", he added.
He conducted experiments to measure water clarity and suspended solids, the nutrient content, particularly nitrogen and phosphorus and also biological oxygen demand, an indicator of organic pollution such as animal or human waste.
He also used a netting system to capture animals living in the river and then detailed what was found.
There were several dozen species there but he was interested in three in particular, mayfly nymphs, caddis fly larvae and stone fly larvae. These three are sensitive to pollution and their absence is a recognised sign of pollution, he said.
He found that the three key species disappeared from the river below Fort Bridge, a short distance downriver from the two reservoirs along the Dodder. This indicated poor water quality that left it impossible for these species to survive.
He also found that species variety overall increased sharply just below the weir at Clonskeagh, probably because the river picks up more oxygen when it is churned up cascading down the weir, he suggests.
The serious threat to coral reefs caused by climate change helped inspire another Young Scientist competitor to learn more about coral.
His project provides valuable information about how to keep tank-grown corals happy and healthy.
"Coral reefs have been there for aeons, since before the dinosaurs. Now that global warming is happening the coral aren't able to keep up with the rate of environmental change," explained Ciarán Doyle (17), a fifth-year student at Blackrock College, Dublin.
Heat can kill coral but so too can subtle changes in seawater chemistry, pollution and too much fresh water.
Ciarán decided to study corals in a 76-litre tank at home in order to learn about their use of chemicals and nutrients taken from the surrounding water. His goal was to understand how the coral polyps, the tiny animals that are the living part of coral, took calcium from the water to construct their skeletons, the calcification build-up that leads to a reef. He also wanted to see if he could speed growth by changing the mix of calcium ions, nutrients and other substances needed by the polyps to live and grow.
He also experimented with the pH of the water because these chemical reactions take place in an alkaline environment.
"The main thing for coral health is stability," Ciarán stated. "They are very sensitive animals."
He believes the results of his study show that corals can be grown and maintained in sound health by giving them the right conditions, information that could be useful if climate-driven coral destruction continues.
