Lee Kong Chian Natural History Museum

Fish Survey

Description

Fish surveys have been conducted in various habitats within Singapore to determine the baseline diversity of fishes. One of the earliest comprehensive fish surveys in Singapore was a study on reef fishes around Pulau Salu conducted in the early 1980s. It was carried out as a visual survey performed while SCUBA diving. Since then, several surveys have been conducted in both marine habitats as well as freshwater habitats such as streams and reservoirs around Singapore.


Methods

Different survey methods are employed depending on the type of habitat and the type of fish targeted.

A visual census can be used as a survey method, however this often require the need for surveyors to SCUBA dive. Other methods involve trapping of the fishes using different forms of nets, hand reels and rods, and stunning fish with clove oil.

Trammel nets consists of two or three mesh layers target fish that are found at or near the substrate. This method can be used for both inland freshwater areas or in marine waters.

Seine nets hangs vertically in water with the bottom edge being weighed down by weights while the top end have floats attached to it. Seine nets are good for surveying fishes that live on or near the seabed in areas where the substrate is relatively flat but with obstacles such as in seagrass meadows. It is also good for catching schooling fish.

Cast nets are circular nets edged with weights. As it is being cast, the net opens up over the water and sink, before being hauled back in. They are used in areas with flat substrate and little obstacles. It is a good alternative for fish that are not attracted to baits.

Rods and hand reels are only good for catching fish that are attracted to prey. This can often be large fishes that are unable to get trap in smaller nets.

Clove oil is sometimes applied to small pools of water to stun fish that are hiding in the pool. The fish are then caught using hand nets. This method is particularly effective for burrowing fishes found in small tidal pools as they will float to the surface. Untargeted fish can be released. Stunned fish will recover quickly in untainted pools of water.


Surveyors

Mpst of the comprehensive fish surveys conducted in Singapore have been carried out by the National University of Singapore, Raffles Museum of Biodiversity Research, Tropical Marine Science Institute, and Public Utilities Board.

Do note that to carry out fish surveys, permits must be obtained from the National Parks Board.

Other Resources

Raffles Museum of Biodiversity Research. 2012. Fish Survey and Training. http://rmbr.nus.edu.sg/projectsemakau/index.php?option=com_semakau_events&task=details&id=48. (Accessed November 2012).

Reef Ecology Study Team, NUS. Local Reef Publications. http://coralreef.nus.edu.sg/publications/list.htm. (Accessed November 2012).

References

Low, J. & L.M. Chou, 1992. Distribution of coral reef fish in Singapore. Pp 130-144. In: Chou, L. M. & C. R. Wilkinson (editors), 3rd ASEAN Science and Technology Week Conference Proceedings. Volume 6. Marine Science: Living Coastal Resources, 21-23 September 1992. Department of Zoology, National University of Singapore and National Science and Technology Board, Singapore, 471 pp.

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