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Ganl. Bull. Singapore 70 (Suppl. 1) 2018 
dohrni ), and would be extirpated from Singapore should anything happen to the Nee 
Soon freshwater swamp forest (Tang et al., 2010). 
Currently, information on aquatic macroinvertebrate groups in Singapore is 
scarce in the scientific literature, with information existing only for certain groups 
(Balkeetal., 1997;Murphy, 1997; Yang etal., 1997; Hendrichetal., 2004). Additionally, 
even for relatively charismatic and well-studied groups such as the odonates, available 
information deals mostly with the adult stage of these insects (Murphy, 1997; Norma- 
Rashid et al., 2008; Tang et al., 2010), with not much being known about their aquatic 
larval stages. More obscure groups such as the ostracods and aquatic mites lack even 
basic information about their presence, distribution and diversity in Singapore. While 
several studies on macroinvertebrates in Singapore’s urbanised water bodies exist 
(Loke et al., 2010; Blakely et al., 2014; Clews et al., 2014), the macroinvertebrates 
in forested areas are less well-known, with scattered reports on selected insect groups 
(e.g. Coleoptera, Hemiptera and Odonata) in the entire Central Catchment Nature 
Reserve (Bailee et al., 1997; Murphy, 1997; Yang et al., 1997), as well as a single report 
on selected insect groups (Hemiptera, Coleoptera, and Odonata) of the Nee Soon 
freshwater swamp forest (Gani, 2013). In recent years, books focusing on specific 
insect groups, such as those by Tang et al. (2010) and Tran et al. (2015), also provide 
a general overview of their target groups in Singapore, including information on the 
populations inside the forests of Singapore. 
The lack of information on the aquatic macroinvertebrates of Singapore, 
particularly baseline ecological information, is meant to be partially addressed by the 
current study, which aimed to undertake representative sampling of macroinvertebrate 
communities across the Nee Soon catchment. This enabled the identification of different 
groups of macroinvertebrates found in the streams, their abundance and distribution 
in the Nee Soon drainage. This is the first dedicated and relatively comprehensive 
quantitative survey of the presence of aquatic macroinvertebrates in the Nee Soon 
drainage, allowing for the establishment of baseline data regarding the aquatic 
macroinvertebrates found in the freshwater swamp forest. This data will allow for 
more informed management decisions to be made regarding the Nee Soon freshwater 
swamp forest, especially with regards to its conservation. 
Methods 
Study sites 
The Nee Soon freshwater swamp forest is located in the Central Catchment Nature 
Reserve, roughly bounded by the Upper Seletar Reservoir, the Upper Peirce Reservoir 
and the Seletar Expressway. It is the last remaining freshwater swamp forest found 
in Singapore, and is accorded “protected” status as a nature reserve on account of 
its inclusion in the Central Catchment Nature Reserve, as well as its use for military 
training (Ng & Lim, 1992) with the presence of a military firing range within the Nee 
Soon catchment (Fig. 1). The Nee Soon freshwater swamp forest is drained by a 
single stream network, originating in central Singapore and draining roughly northeast 
