Living Smart

II ENVIRONMENT & SUSTAINABILITY 046 047 per person per day. By using a family of four as the basis for calculation, the quantity of plastic bags discarded in one day could only be completely eliminated if 700 larvae were used to consume the bags 24/7 for more than a month. Separately, Science Magazine reported in 2016 that scientists at Japan’ s Kyoto Institute of Technology had identified bacteria that could degrade plastic bottles. And then a group of scientists from the University of Portsmouth in the UK created a mutant enzyme with improved capacity by accident earlier this year. It could break down plastic bottles at a much faster rate. Compared with breeding insects, it is easier and more economical to cultivate bacteria, so scientists hope to extract the bacteria’ s digestive enzymes to treat plastic waste. However, if insects were to be removed from this equation, plastic production and elimination is purely a resource-draining process. Gut bacteria of the insects degrade plastic to release nutrients for the insects’ use, and then the insects become food for other organisms and this forms nature’ s enormous cycle of life. Breaking the cycle may not be beneficial to humankind in the long run. Some mush r ooms ar e a l so good a l t e rna t i ves f o r decomposing plastic, such as old car tires. Efforts are being made to grow edible mushrooms from plastic waste. Although it will still take a while before such products become commercially available, the idea of converting waste into food is certainly an interesting research direction. Published on September 05, 2018 Time to know the secrets of our waters Prof. Karen CHAN Adjunct Assistant Professor, Division of Life Science W e are usually viewed as an international financial hub, but is that all? With the recent debate on land development, one may now be aware that 40 percent of our land is designated as country parks. What about the other substantial portion of our territory, namely the 1,300 square kilometers of water that surrounds our 1,100 square kilometers of land? Other than the charismatic Chinese White Dolphins, how much do we know about the aquatic residents of the SAR? For instance, 84 species of reef-forming corals are found in Hong Kong – rivaling the total found in the Caribbean. But how many of us can name, let alone have encountered, one of these organisms in the natural environment? Indeed, understanding what is in our waters – as broad and elementary as it may sound – is a required step if our city is to take sustainable development seriously. Hong Kong’ s waters, as a confluence of the open ocean and the Pearl River, have a wide variety of marine life, many of which are still undescribed or unknown. Marine organisms often have complex life histories – adults release their gametes at sea and