We bought fish for the tagging study from commercial bag-net operators who work the
Tonle Sap River. This bag-net fishery, which is located in the southern-most stretch of the
river (Figure 1), comprises 14 rows. Each row contains between one and seven nets. Each
individual net is cone-shaped, being 25 metres in diameter at the mouth and 120 metres
in length. Almost all the fish we tagged during this study were collected from bag-net row
numbers two, three, and four, which are approximately 4-6 km upstream of Phnom Penh.
The bag-net fishery is a large seasonal fishery that targets fish moving out of the Tonle
making it an appropriate source of fish. With the
cooperation of the bag-net operators, we were able to collect, tag, and release fish with ease.
Sap Great Lake
Tagging and release took place during the October 2003–March 2004 and the October 2004–
March 2005 dai open seasons. Fifteen species of fish were tagged in total (Tables 1, 2, 3 and
4). We chose these species on the basis of three criteria: (i) because we understood that they
were migratory species; (ii) the availability of suitably sized fish, and (iii) the fish vendors’