Field experiments to improve the efficacy of gargoor (fish trap) fishery in Kuwait's waters

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.

Utility of gillnets for selectively targeting penaeids off Iran

In response to concerns over the mortality of discards and other negative environmental impacts of otter trawling for penaeids,the utility of bottom-set gillnets deployed by artisanal vessels to target Penaeus monodon,Metapenaeus affinis and other retained species by-product was assessed in the Sea of Oman.Two gillnets(each comprising several 80-m panels for total lengths of up to 1.3 km)were diurnally fished at two locations(off Beris and Govater,eastern Iran)within established penaeid fishing grounds.During 30 days,the total catch was 2721 kg,comprising penaeids(981 kg),eight retained by-product species(598 kg and mostly Otolithes ruber,Cynoglossus bilinearus and Carangoides talamparoides)and 19 discarded species(1142 kg).The catch-per-unit-of-effort(CPUE,kg/gillnet-panel⋅hour-fished)of targeted penaeids and by-product varied significantly between areas(0.5-1.0 kg),but nevertheless reached economically viable levels.The CPUEs of total bycatch were similar at both sites(<0.5 kg)and no marine turtles were caught.The concomitant ratios of retained-catches-to-bycatch were considerably less than those for regional penaeid-trawl fisheries.Nevertheless,while gillnet selectivity was satisfactory for M.affinis,most of the P.monodon were smaller than their carapace length at maturity at both fished sites.The results support using gillnets to target penaeids and by-product species as an alternative to otter trawling in the Sea of Oman;albeit with ongoing assessments of modifications to maximise selectivity.

Fishing for Atlantic cod (Gadus morhua) with pots and gillnets: A catch comparison study along the southeast coast of Labrador

Gillnets are the primary fishing gear used to catch Atlantic cod(Gadus morhua)in coastal areas of Newfoundland and Labrador but are known to catch non-target species and produce lower quality fish than live-catch methods.The purpose of this study was to compare the catch efficiency of collapsible cod pots against gillnets near the Gilbert Bay Marine Protected Area(MPA),Labrador,where a reduction in by-catch is needed.Results showed that one cod pot caught half as much Atlantic cod as a gillnet,and pots had a relatively stable catch rate throughout the sampling period,whereas gillnets caught relatively few fish later in the sampling season.Moreover,nearly all fish sampled with pots were caught alive undamaged,whereas most gillnet-caught fish experienced damage or mortality.As a conservation measure pot-fishing would enable fishing within close proximity to the Gilbert Bay MPA and the live-release of visually distinguishable Gilbert Bay cod,thereby mitigating against the negative effects of commercial fishing on this protected Atlantic cod population.