Yellowfin tuna (Thunnus albacares) is one of the most commercially important fish species for South Pacific island nations and territories and for effective conservation efforts it is important to understand the facto...Yellowfin tuna (Thunnus albacares) is one of the most commercially important fish species for South Pacific island nations and territories and for effective conservation efforts it is important to understand the factors which affect its time series pattern. Our research was aimed at elucidating the climatic factors which affected the trajectory of the yellowfin tuna stock in the Eastern and Western South Pacific Ocean. We utilized various climatic factors for the years t - n with n = 0, 1, ..., 8 and investigated their statistical relationship with the catch per unit effort (CPUE) of yellowfin tuna stock from 1957-2008 for three South Pacific zones ranging from the East to the West Pacific Ocean within the coverage area of the Western and Central Pacific Convention Area. Results showed that the climatic conditions of: (i) the global mean land and ocean temperature index (LOTI), (ii) the Pacific warm pool index (PWI) and (iii) Southern Oscillation Index (SOI) had significant relationship with the CPUE of yellowfin tuna in all three zones. LOTI, PWI and SOI were used as independent variables and fitted through modeling to replicate the CPUE trajectory of the yellowfin tuna in Zone 1, Zone 2 and Zone 3. Model selection was based on significant parameter estimates (p < 0.05), Akaikes Information Criterion (AIC) and R2 values. Models selected for all three zones had LOTI, PWI and SOI as the independent variables. This study shows that LOTI, PWI and SOI are climatic conditions which have significant impact on the fluctuation pattern of the yellowfin tuna CPUE in the Eastern and Western South Pacific Ocean. From the findings of this study it can be recommended that when management decisions are made for yellowfin tuna fishery conservation and sustainability in the Eastern and Western South Pacific, it is imperative to take the effect of climatic factors into account.展开更多
Objective:To recored the infection of Acanthocephalan parasite,(Echinorhynchus sp.)in adult yellowfin tuna(Thunnus albacares).This is the first report of acanthocephalan Echinirhynchus sp attached to yellowfin tuna an...Objective:To recored the infection of Acanthocephalan parasite,(Echinorhynchus sp.)in adult yellowfin tuna(Thunnus albacares).This is the first report of acanthocephalan Echinirhynchus sp attached to yellowfin tuna and moreover prevalence,mean intensity and mean abundance was observed.Methods:Totally 1001 yellowfin tuna fishes were collected throughout the year of 2012 from the coast of Nagapattinam(10°45'36.25"N and 79°50'59.54"E),Tamil Nadu,India.The collected fishes were washed with fresh water to remove debris and immediately stored in ice,and brought to the laboratory.Intestines were placed in normal saline(0.85%NaCl).The worms were fixed in alcohol/formalin/(AFA)fixative and in 70%ethanol until processed for identification.Results:Totally 1001 yellowfin tuna was examined out of 387(52.67%)hosts were infected with acanthocephalan(Echinorhynchus sp.).The proboscis Echinorhynchus sp.was long,cylindrical with cylindrical with a uniform width measured(0.41±0.02)mm in length and(0.12±0.03)mm in width.The endo parasite prevalence,intensity and abundance was recorded as 52.67%,12.46%,and 5.43%respectively.Conclusions:This current phenomena was carried out to report of acanthocephalan Echinorhynchus sp.attached the new host of yellowfin tuna from Nagapattinam coast.Moreover,parasitological investigations are required to determine endo parasites of host due to its importance and numerous occurring among most important marine food fishes in world wild.展开更多
文摘Yellowfin tuna (Thunnus albacares) is one of the most commercially important fish species for South Pacific island nations and territories and for effective conservation efforts it is important to understand the factors which affect its time series pattern. Our research was aimed at elucidating the climatic factors which affected the trajectory of the yellowfin tuna stock in the Eastern and Western South Pacific Ocean. We utilized various climatic factors for the years t - n with n = 0, 1, ..., 8 and investigated their statistical relationship with the catch per unit effort (CPUE) of yellowfin tuna stock from 1957-2008 for three South Pacific zones ranging from the East to the West Pacific Ocean within the coverage area of the Western and Central Pacific Convention Area. Results showed that the climatic conditions of: (i) the global mean land and ocean temperature index (LOTI), (ii) the Pacific warm pool index (PWI) and (iii) Southern Oscillation Index (SOI) had significant relationship with the CPUE of yellowfin tuna in all three zones. LOTI, PWI and SOI were used as independent variables and fitted through modeling to replicate the CPUE trajectory of the yellowfin tuna in Zone 1, Zone 2 and Zone 3. Model selection was based on significant parameter estimates (p < 0.05), Akaikes Information Criterion (AIC) and R2 values. Models selected for all three zones had LOTI, PWI and SOI as the independent variables. This study shows that LOTI, PWI and SOI are climatic conditions which have significant impact on the fluctuation pattern of the yellowfin tuna CPUE in the Eastern and Western South Pacific Ocean. From the findings of this study it can be recommended that when management decisions are made for yellowfin tuna fishery conservation and sustainability in the Eastern and Western South Pacific, it is imperative to take the effect of climatic factors into account.
基金Supported by Department of Biotechnology,(BT/PR14992/SPD/11/1332/2010),Government of India,New Delhi.
文摘Objective:To recored the infection of Acanthocephalan parasite,(Echinorhynchus sp.)in adult yellowfin tuna(Thunnus albacares).This is the first report of acanthocephalan Echinirhynchus sp attached to yellowfin tuna and moreover prevalence,mean intensity and mean abundance was observed.Methods:Totally 1001 yellowfin tuna fishes were collected throughout the year of 2012 from the coast of Nagapattinam(10°45'36.25"N and 79°50'59.54"E),Tamil Nadu,India.The collected fishes were washed with fresh water to remove debris and immediately stored in ice,and brought to the laboratory.Intestines were placed in normal saline(0.85%NaCl).The worms were fixed in alcohol/formalin/(AFA)fixative and in 70%ethanol until processed for identification.Results:Totally 1001 yellowfin tuna was examined out of 387(52.67%)hosts were infected with acanthocephalan(Echinorhynchus sp.).The proboscis Echinorhynchus sp.was long,cylindrical with cylindrical with a uniform width measured(0.41±0.02)mm in length and(0.12±0.03)mm in width.The endo parasite prevalence,intensity and abundance was recorded as 52.67%,12.46%,and 5.43%respectively.Conclusions:This current phenomena was carried out to report of acanthocephalan Echinorhynchus sp.attached the new host of yellowfin tuna from Nagapattinam coast.Moreover,parasitological investigations are required to determine endo parasites of host due to its importance and numerous occurring among most important marine food fishes in world wild.
