Singapore’s 17 reservoirs are teeming with life, each one FOOD WEB OF Apex Primary Biodiversity at a unique underwater world boasting a rich biodiversity of sh, SERANGOON RESERVOIR predators consumers aquatic plants and other species. Cheryl Tan takes a deep Secondary Primary consumers producers Serangoon Reservoir dive into Serangoon Reservoir and reveals what it has to offer.

WHAT IS FOUND IN SERANGOON RESERVOIR? Sarimbun Kranji Lower Seletar Punggol Pulau Tekong Total estimated sh Dominant Reservoir Reservoir Reservoir Reservoir Reservoir population size sh species Orinoco Common peacock bass PISCIVOROUS FISH snakehead Upper Serangoon 77,369 Green chromide Seletar Reservoir Total number of species of... Murai Reservoir Reservoir Native sh 6 Non-native sh 15 Upper Peirce Reservoir Poyan Lower Peirce Reservoir Reservoir Green Tengeh Jurong Lake MacRitchie Bedok Midas cichlid chromide Reservoir Reservoir Reservoir Pandan Reservoir

Age of reservoir Type of reservoir Marina Unprotected/Coastal 10 years Reservoir Mozambique Zebra Javanese ricefish tilapia tilapia

SURVEY TECHNIQUES Golden tank goby Boat electro shing Quetzal Mayan Used for catching shes cichlid to depths and distances Barcheek goby cichlid of up to 3m from the boat. This technique entails • Marbled gudgeon “Soon hock” Eartheater Giant placing electrodes in the cichlid gourami water that discharge pulses INVERTIVOROUS of electrical currents, which FISH OMNIVOROUS FISH rst attract and then stun the sh as they swim closer to the boat. • This helps to capture a wide range of species Vermiculated sailfish catfish across all sizes that are HERBIVOROUS otherwise FISH dif cult to catch using conventional Prawns methods. Electrodes deliver current to the water Dragonfly and Gastropods Gill netting Fish tagging damselfly nymphs Used for catching pelagic shes in • The sh that are captured are individually tagged PREDATORY deeper and more open waters. by researchers, and then released back into the water. INVERTEBRATES Chironomids Zooplankton • Determining the recaptured proportions of HERBIVOROUS

• This is a vertical panel of • Depending on the mesh of the net, tagged to untagged shes can give researchers INVERTEBRATES netting that hangs in the this is typically designed to allow sh an estimate of the different sh species Riparian Phytoplankton middle of the water column. to get caught in the netting material. populations in the reservoir. plants and benthic algae PRIMARY PRODUCERS Taking measurements of the specimen

A radio-frequency identification tag is inserted into a fish

Weighing the fish

Source: PUB PHOTOS: JASON QUAH, COURTESY OF ROCHELLE CHAN, RAYSON LIM, CLAUDIA TAN, MAXINE MOWE AND TAN HEOK HUI STRAITS TIMES GRAPHICS: LIM YONG