To save Singapore's corals, 14 undergraduates last month went up to 12m underwater to monitor and photograph the reefs surrounding Pulau Hantu.
They did so as part of a marine conservation project called Reef Alert, partially funded by the National Youth Council. Data collected will be sent to the National Parks Board.
1. Survey area is decided based on factors such as currents, layout of the reef, time and available manpower.
A grid-like structure called a quadrat is made using plastic pipes and rope.
Measuring 1m by 1m, each quadrat has 16 squares of equal size which the divers use to frame their photographs.
The second layer of the quadrat supports an underwater camera to ensure that photographs of the squares are taken from the same distance.
2. The first group of divers marks out the survey area using tape measures.
A clothes peg is placed at 1m intervals along the line.
For the first dive, the group aims to cover a reef area of about 40sq m, or 40 quadrats.
3. In groups of three, the students photograph the rich marine life using the quadrat.
It takes each team about 45 minutes to monitor 10 quadrats.
Data analysis is done on land.
Students will screen the photos, and identify and quantify the types of marine life - such as the types of coral and algae - found in each image.
What are corals?
They are made up of colonies of tiny organisms called polyps.
Under environmental stress, such as a change in temperature, corals will expel algae.
Loss of algae causes coral bleaching, depriving them of a food source.
Besides corals, Singapore has other underwater gems
- The Clown Fish, which is often found among sea anemones, lives in Singapore's southern waters.
- A Lion Fish, with red and white stripes and regal fins, was spotted in the intertidal area regal of Pulau Hantu.
- The Feather Star, which resembles a flower with petals like birds' feathers, is not a plant but an animal, and can grow up to 20cm in diameter. It can be found on the reefs at the Southern Islands, or on the sea floor.
This article was first published on April 2, 2015.
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