SBR- Content.pmd - INBO

7 - FisheriesThe conversion of floodplains into arable land, especially rice fields, is a serious threat to a crucialecological habitat, and therefore to fish production and diversity. It has been determined by aerialphoto surveys conducted in 1973-1976 and 1992-1993, that 33 percent of the flooded forest area ofCambodia was cleared in that 20-year period. 91 Around the Great Lake, 27 percent of the floodedforest cover was cut during the same period. 92 It is imperative that as much flooded forest as possiblebe preserved if fisheries productivity is to be maintained. To achieve this, the communities responsiblefor fisheries management must be convinced to conserve and protect flooded forest and wetlandhabitats, because the loss of critical fish habitats is usually irreversible. 93Development projects for the Tonle Sap Lake, such as the building of harbours, roads, and oil andgas exploration, will increase accessibility and employment in the area and bring in more people.Increased population pressure will result in destruction of natural habitats and ecological damageas land is converted for agriculture and trees are cut for fuel. Another solution would be to createemployment opportunities in areas outside the floodplains to relieve development pressure on theflooded forests and critical wetlands.2.7.4 Fishing pressureThe Mekong fishery comprises at least 120 commercial species, hundreds of fishing gear types, and40 million fishers, many of whom have low levels of literacy. At least 180 different fishing gearshave been identified in Cambodia alone. 94 There are an equally diverse number of gears in LaoPDR. 95 Given this situation, it is difficult to accurately monitor fishing yield and effort.The most valuable long-term fish capture data sets have been collected from the dai fishery on theTonle Sap River by the MRC Fisheries Programme. Time series data indicate that fish yield iscorrelated with average peak flood levels. Annual dai catches for October in the Tonle Sap Riverclosely follow the average October water level in the same river. 96 Flood control measures, includingdam construction, that lower average peak flood levels can reduce fish catches. 97The mean fish size for different fish species caught in thegill net Scaphognathops fishery in Khong District,Champasak Province, Lao PDR from 1993 and 1998 98was also variable for all species, but no species wasdeclining in mean size. The number of species caughtbetween 1993 and 1998 varied from 30 to 76, but thedata give no indication that the number of species in thecatches is declining.Giant lift nets in actionFishers also complain that their catches have declinedover time, and data show that catch per fisher has declinedapproximately 44 percent between the 1940s and 1995.Despite this, the total fish yield in the Tonle Sap area hasincreased 84 percent from 125,000 to 230,000 tonnesduring the same period because of the massive increasein the number of fishers. While the overall catch volumeof the Tonle Sap fishery may yet increase further, and theproportion of small, prolific, fast maturing and growingspecies like Henicorhynchus spp. in the catch mightincrease, the overall value of the fishery may decline. 99115