Data mining and stock assessment of fisheries resources in Tonle Sap Lake, Cambodia

Abstract

The potential of catch per unit effort (CPUE) analysis based on statistics of local fisheries in Tonle Sap Lake in Cambodia was evaluated. The fishery statistics system was improved through a cooperative project conducted by the Department of Fisheries and the Mekong River Commission between 1994 and 2000, especially in the seven provinces adjacent to Tonle Sap Lake. However, the fisheries statistics were not effectively utilized for sustainable stock management. After the cooperative project, fish catch data sorted by species or species group were collected at the province level in the seven provinces. Another recent project also revealed the numbers of fishing gears that operated in the seven provinces. The CPUEs of ten species in Kampong Thom Province-including Channa micropeltes and Cirrhinus spp.-could be calculated from 1994 to 2007, because these are caught solely using bamboo fence systems or barrages. CPUE analysis clarified that stocks of high-price fishes such as Ch. micropeltes, Hampala spp., and Pangasius spp. have deteriorated while those of relatively low-price fishes such as Cirrhinus spp., Cirrhinus microlepis, Cyclocheilichthys enoplos, and Channa striata have increased in recent decades.

Toward an ecological understanding of a flood-pulse system lake in a tropical ecosystem: Food web structure and ecosystem health

“…The high EE values of fish groups illustrated the pressure on the resources suffered from fishing activities as well as predation pressure for the forage fish groups (i.e., mud carp, small herbivores and small fish). This result was consistent with many previous studies on the fishery production of the lake that have drawn their concerns on over exploitation of fisheries resources in the lake (Enomoto et al, 2011). In addition, Enomoto et al (2011) illustrated the fluctuation of CPUE (catch per unit effort) of snakehead (Channa sp.)…”

“…This result was consistent with many previous studies on the fishery production of the lake that have drawn their concerns on over exploitation of fisheries resources in the lake (Enomoto et al, 2011). In addition, Enomoto et al (2011) illustrated the fluctuation of CPUE (catch per unit effort) of snakehead (Channa sp.) and catfish (Pangasius sp.)…”

“…Many previous studies on fish production of the lake have confirmed this compounded by the over harvesting of the commercial species from the lake (Cooperman et al, 2012;Enomoto et al, 2011). Overfishing could significantly impact the food web structure of the lake causing the shift from k-selected species (large long-lived species) to r-selected species (small fast growing species) (Travers et al, 2010).…”

“…), and gourami fish (Trichopodus sp.). In 2008, the catch statistics from the fishing lots in the East part of TSL (Kampong Thom province) illustrated that the CPUE, i.e., the total catch (t) divided by the total length of bamboo fence systems (km), of snakehead and catfish were about 2 t km −1 lower than mud carp (6 t km −1 ) (Enomoto et al, 2011). Moreover, Lamberts (2001) produced length-weight relationships for soldier river barb (Cyclocheilichthys enoplos) and showed that this species, which can reach a total length of 90 cm, was found only at lengths of up to or less than 45 cm, which is the most common in the lake.…”

“…Recent studies have shown that TSL fisheries exert over exploitation. Subsequently, multiple significant indicators have shown that the system, previously home to many giant catfishes, giant barbs and stingrays, is now dominated by small and low value species (Cooperman et al, 2012;Enomoto et al, 2011), questioning the sustainability of the fisheries in the lake. As a matter of fact, overfishing can impact the food web structure and change the abundance of predators that can alter the prey abundance leading to a cascade of trophic effects (Sala et al, 1998).…”