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 หัวเรื่อง:ไม่มีชื่อไทย (ชื่ออังกฤษ : Fish in the Pak Panang Bay and River in Relation to the Anti-Salt Dam Operation, Part I: Assemblage Patterns of the Marine and Brackish Water Fish) ผู้เขียน: ทวนทอง จุฑาเกตุ, อมรศักดิ์ สวัสดี, Thanitha Thapanand Chaidee, Sutheera Thongkhoa,  นายปิยะพงศ์ โชติพันธุ์ สื่อสิ่งพิมพ์:pdf AbstractSpatio-temporal patterns of marine and brackish water fish assemblages gradated from the upstream of the anti-salt dam “Uthokawiphatprasid” dam to the Pak Panang Bay, southern of Thailand. The samples were collected between March 2006 to June 2007at six sampling sites (three sites each from above and below the dam). A total of 70 fish species belonging to 68 genera and 44 families were sampled. To analyze patterns of fish assemblages, an artificial neural network (ANN) in the form of a self-organizing map (SOM) was applied. The sample-combinations (sluice gate regime (opening or closing), sampling stations and months of sampling) were classified into four clusters related to the spatial location and sluice gate regimes. Six assemblage patterns were further explained by the probability of occurrences and ranges of salinity levels. The largest group was opportunistic marine fish (21 species) followed by true brackish water fish (17 species). Others comprised of steno- and eury-haline fish as well as the anadromy. The likely impacts of each guild due to the dam regulations and further studies for conserving these fish were also discussed. |
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หัวเรื่อง:ไม่มีชื่อไทย (ชื่ออังกฤษ : Fish in the Pak Panang River and Bay in Relation to the Anti-Salt Dam Operation, Part II: Trophic Model) ผู้เขียน:อมรศักดิ์ สวัสดี, ทวนทอง จุฑาเกตุ, Thanitha Thapanand Chaidee, Sutheera Thongkhoa, นายปิยะพงศ์ โชติพันธุ์ สื่อสิ่งพิมพ์:pdf AbstractThe ECOPATH software program was used to study the mass-balanced trophic structures and functioning of the aquatic organisms of the Pak Panang Bay and River (lower portion) to gain insight into the ecosystem due to the operation of the Uthokvibhajaprasid Dam. The resulting models were authenticated as indicated by the output parameters. There were 20 and 25 compartments for the estuary and river models, respectively. The trophic levels varied from 1.0 for primary producers and detritus to about 3.0 for carnivorous fish. Gross efficiency of the fishery indicated intensive efforts in both areas. Both systems were considered intact, since the transfer efficiency was between 10 to 15%. Small-sized brackish-water plankton feeders played an important role in linking the lower trophic organisms and top predators. Improper regulation of the sluice gates would impact these groups and result in an imbalance of the ecosystems. |
หัวเรื่อง:ไม่มีชื่อไทย (ชื่ออังกฤษ : Fisheries in the Mun River: A One-Year Trial of Opening the Sluice Gates of the Pak Mun Dam, Thailand) ผู้เขียน:ทวนทอง จุฑาเกตุ, Chaiwut Krudpan,, Praneet Ngamsnae, Kanjana Payooha, Thanatip Lamkom สื่อสิ่งพิมพ์:pdf AbstractThe changes in fisheries during the trial on the opening of sluice-gates of Pak Mun Dam (July 2001 to June 2002) were investigated. There were 184 fish species from 44 families found, with some species recognized to extirpate from the Mun River. Shannon’s diversity index ranged from 1.92 to 3.14. Catch per unit of fishing effort ranged from 0.38 to 1.70 and 0.61 to 2.71 kg set-1 night-1 in down- and up-stream, respectively. Fish upstream migrations during the rainy season were observed. Incomes from fishing activities were 16,366 Thai Baht yr-1 per household. Traditional activities, especially related to fisheries, returned and income from fishing also increased during the study period. |
 หัวเรื่อง:ไม่มีชื่อไทย (ชื่ออังกฤษ : Costs and Returns of the Commercial Fisheries in the Man-made Lakes in Surin Province, Thailand) ผู้เขียน:Samnao Saowakoon, Hattachai Boonjung, Praneet Ngamsnae, ทวนทอง จุฑาเกตุ สื่อสิ่งพิมพ์:pdf AbstractThree types of fisheries, viz. gillnets, longlines and traps, in the two irrigated man-made lakes in Surin province in the NE of Thailand, were analyzed in terms of profits Gillnets showed the highest operation cost, 8,891.2 baht per fishing season following by 5,850.3 and 4,776.4 baht per fishing season for longlineand trap- fisheries respectively. From the catch composition in each gear and the current market values of individual species, the current incomes that the fishers obtained from their fisheries were 37.4, 54.4 and 52.7 baht kg-1 for gillnet, longline and trap fisheries respectively. According to fishing costs per one fishing season, CpUE and number of fishing days, it was estimated that the break-even prices in the respective fisheries were 10.1, 14.8 and 10.3 baht kg-1, which indicated that the fishers have made a profit. The monitoring program and community based management on lake environments and fisheries resources as well as the fish stock enhancement program are recommended to sustain the fisheries. |
ที่มา:KASETSART UNIVERSITY FISHERIES RESEARCH BULLETINหัวเรื่อง:ไม่มีชื่อไทย (ชื่ออังกฤษ : Ecosystems in Sirinthorn and Nam Ngum Reservoirs; A comparison) ผู้เขียน:ทวนทอง จุฑาเกตุ, Jacques Moreau, Boonsong Srichareondham, MalasriKumsri สื่อสิ่งพิมพ์:pdf AbstractTrophic models were constructed for Sirinthorn Reservoir (Thailand) and Nam Ngum Reservoir (Lao PDR), using ECOPATH software to understand their ecosystems. The models reveal that the trophic structure of the reservoirs is similar. Results show that the ecosystems in both lakes are sustained and considered as productive reservoirs. The transfer efficiency is between 10 and 15 % at all levels, indicating an intact food web. In both reservoirs, total fish productions can support fishing activities. There are also presented the (1) energy flow in each trophic level, (2) mixed trophic impact, in term of predator-prey relationship and fishery and (3) calculate the net biomass and production of the groups of organisms. The fishery operates at a trophic level around three, meaning that mainly zoophagous fishes are targeted. |
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