Fish traps were investigated to understand the effects of season, bait type, trap size, and trap soak time on catch rates, catch composition, and trap loss rates from March 2004 to September 2005, to improve the perfo...Fish traps were investigated to understand the effects of season, bait type, trap size, and trap soak time on catch rates, catch composition, and trap loss rates from March 2004 to September 2005, to improve the performance and management of Kuwait＇s gargoor （cage style fish trap） fishery, which used to be the nation＇s most important one in terms of value and landings volume. Catch rates were the highest in April/May （5 8 kg/trap haul） and again in December （7 kg/trap haul）. Bait type and trap size also affected catch rates and species composition. Of the seven baits tested, the best catch rates, 〉5 kg/trap haul, occurred with cuttlefish （Sepia pharaonis）, but wolf-herring （Chiroeentrus dorab） and mullet （Liza klunzingeri） also produced good results （4-5 kg/trap haul）. Within the five tested sizes, the two largest-sized traps captured more fish and larger size fish. Analysis of variance （ANOVA） showed significant differences of catch rate among traps with different baits as well as among traps of different sizes. Duncan test further revealed these differences between two specific baits and sizes. Cluster Analysis of species composition showed more differences among different baits than among different trap sizes. Longer soak times did not result in larger catch rates, but increased trap loss. About 10-day soak time resulted in trap loss 7%, while 40-day soak time could result in a loss of around 20%. Consequently, it is recommended that the gargoor be checked every 10 or fewer days. The average overall catch rate during the study period was lower than that of 1980s （4.5 vs. 5.8 kg/trap haul）, indicating a possible decline offish abundance in Kuwait＇s waters. It is recommended that the number of gargoor fishing boats and gargoors from each boat should be limited to allow stock rehabilitation.展开更多
Background:Waterbirds are globally declining as a result of habitat loss, alteration or degradation. Fishing activities may affect waterbird distribution, abundance and diversity, and traditional fishing activities of...Background:Waterbirds are globally declining as a result of habitat loss, alteration or degradation. Fishing activities may affect waterbird distribution, abundance and diversity, and traditional fishing activities often enhance waterbird abundance. We tested this hypothesis by studying the abundance and diversity of selected common waterbird species in the Kadalundi–Vallikkunnu Community Reserve, a globally significant wetland in southwestern India in relation to fishing activities.Methods:We monitored waterbird abundance four times a month from 2012 to 2015 using direct observation method during low tide. Traditional bamboo fish traps were deployed during the first and third weeks of each month. ANOVAs(one-way and multi-way) were used to examine how waterbird counts diversity varied in relation to years, seasons and period of fishing traps. Additionally we conducted a linear regression to examine the relationship between fish occurrence and waterbird counts and diversity.Results:Waterbird counts varied with years and seasons, with the maximum counts being recorded during the postmonsoon(winter). Individual species varied in their responses to trap deployment. Small waterbird species usually forage in shallow shorelines, increased during trap deployment whereas the larger waterbirds were not affected by trap deployment because they tend to hunt in deeper waters. The total fish captured was an important predictor of both waterbird abundance and diversity.Conclusion:In this study we documented a positive association between traditional fish trap deployment and waterbird counts and diversity. Providing high quality habitats for waterbirds as well as effective sustainable livelihoods through traditional fisheries is a critical management issue.展开更多
The utilization of fish embryos in toxicity testing of hazardous chemicals has recently been adopted in order to satisfy stricter rules and regulations related to using adult animals in toxicity testing. This paper pr...The utilization of fish embryos in toxicity testing of hazardous chemicals has recently been adopted in order to satisfy stricter rules and regulations related to using adult animals in toxicity testing. This paper presents optimising steps towards improving zebra fish embryo production in the laboratory. Culture conditions were maintained in the aquaria as stipulated in the OECD draft proposal for a new guideline on fish embryo tests. Furthermore, a sequence of steps were adopted and followed to improve upon previous work done in the lab in 2006. About 200 eggs were produced in one spawn trap within an hour of onset of light, an improvement over the 50 - 60 eggs produced in the previous work. This result demonstrates that with the right culture conditions and proper optimisation of procedure the required number of embryos needed for toxicity testing can be obtained.展开更多
基金Supported by the Kuwait Foundation for the Advancement of Science (KFAS)the Public Authority for Agriculture and Fisheries Resources(PAAFR)+1 种基金the Project of Investigation to Improve Kuwait’s Demersal Trap Fishery of Kuwait Institute for Scientific Research (KISR)which was conducted at the Mariculture and Fisheries Department of KISR
文摘Fish traps were investigated to understand the effects of season, bait type, trap size, and trap soak time on catch rates, catch composition, and trap loss rates from March 2004 to September 2005, to improve the performance and management of Kuwait＇s gargoor （cage style fish trap） fishery, which used to be the nation＇s most important one in terms of value and landings volume. Catch rates were the highest in April/May （5 8 kg/trap haul） and again in December （7 kg/trap haul）. Bait type and trap size also affected catch rates and species composition. Of the seven baits tested, the best catch rates, 〉5 kg/trap haul, occurred with cuttlefish （Sepia pharaonis）, but wolf-herring （Chiroeentrus dorab） and mullet （Liza klunzingeri） also produced good results （4-5 kg/trap haul）. Within the five tested sizes, the two largest-sized traps captured more fish and larger size fish. Analysis of variance （ANOVA） showed significant differences of catch rate among traps with different baits as well as among traps of different sizes. Duncan test further revealed these differences between two specific baits and sizes. Cluster Analysis of species composition showed more differences among different baits than among different trap sizes. Longer soak times did not result in larger catch rates, but increased trap loss. About 10-day soak time resulted in trap loss 7%, while 40-day soak time could result in a loss of around 20%. Consequently, it is recommended that the gargoor be checked every 10 or fewer days. The average overall catch rate during the study period was lower than that of 1980s （4.5 vs. 5.8 kg/trap haul）, indicating a possible decline offish abundance in Kuwait＇s waters. It is recommended that the number of gargoor fishing boats and gargoors from each boat should be limited to allow stock rehabilitation.
文摘Background:Waterbirds are globally declining as a result of habitat loss, alteration or degradation. Fishing activities may affect waterbird distribution, abundance and diversity, and traditional fishing activities often enhance waterbird abundance. We tested this hypothesis by studying the abundance and diversity of selected common waterbird species in the Kadalundi–Vallikkunnu Community Reserve, a globally significant wetland in southwestern India in relation to fishing activities.Methods:We monitored waterbird abundance four times a month from 2012 to 2015 using direct observation method during low tide. Traditional bamboo fish traps were deployed during the first and third weeks of each month. ANOVAs(one-way and multi-way) were used to examine how waterbird counts diversity varied in relation to years, seasons and period of fishing traps. Additionally we conducted a linear regression to examine the relationship between fish occurrence and waterbird counts and diversity.Results:Waterbird counts varied with years and seasons, with the maximum counts being recorded during the postmonsoon(winter). Individual species varied in their responses to trap deployment. Small waterbird species usually forage in shallow shorelines, increased during trap deployment whereas the larger waterbirds were not affected by trap deployment because they tend to hunt in deeper waters. The total fish captured was an important predictor of both waterbird abundance and diversity.Conclusion:In this study we documented a positive association between traditional fish trap deployment and waterbird counts and diversity. Providing high quality habitats for waterbirds as well as effective sustainable livelihoods through traditional fisheries is a critical management issue.
文摘The utilization of fish embryos in toxicity testing of hazardous chemicals has recently been adopted in order to satisfy stricter rules and regulations related to using adult animals in toxicity testing. This paper presents optimising steps towards improving zebra fish embryo production in the laboratory. Culture conditions were maintained in the aquaria as stipulated in the OECD draft proposal for a new guideline on fish embryo tests. Furthermore, a sequence of steps were adopted and followed to improve upon previous work done in the lab in 2006. About 200 eggs were produced in one spawn trap within an hour of onset of light, an improvement over the 50 - 60 eggs produced in the previous work. This result demonstrates that with the right culture conditions and proper optimisation of procedure the required number of embryos needed for toxicity testing can be obtained.
