Estudio comparativo de pesca pelágica recreativa entre las artes de línea de mano y curricán en el golfo de Omán, Irán

The choice of fishing gear and catching strategy should be taken into consideration in the management of fish stocks. Here, paired fishing trials in a pelagic recreational fishery compared the catch composition, catch rate and size selectivity between handline and trolling fishing methods in Iranian coastal waters of the Gulf of Oman. Total catch rate was 1.06 fish hr–1 vs 0.88 fish hr–1 for handline and trolling, respectively, a 17% difference which was significant (p < 0.05). Generally, the handline method captured more fish than trolling for most species, but size selectivity tended to be species-specific per gear type. The handline fishing method captured larger talang queenfish (Scomberoides commersonnianus), while trolling captured larger narrow-barred Spanish mackerel (Scomberomorus commerson), pickhandle barracuda (Sphyraena jello) and Indian threadfish (Alectis indicus). Technical measures, such as gear restrictions, could be applied to recreational pelagic fisheries management in the Gulf of Oman. Such measures could improve species-specific exploitation patterns.La selección del equipo de pesca y la estrategia de captura deben ser consideradas en la gestión de stocks pesqueros. En el presente estudio se muestran resultados de tipos, tasas y selectividad de talla de las capturas en una experiencia comparativa de artes de pesca en aguas costeras del golfo de Omán, Irán. Las tasas de captura finales para las artes de línea de mano y curricán fueron de 1.06 y 0.88 peces h–1 respectivamente, mostrando un significativo 17% de diferencia entre ambas (p < 0.05). Por lo general, el arte de línea de mano resultó en una mayor tasa de captura multiespecífica, sin embargo la selectividad de talla se observó arte-dependiente. En el arte de línea de mano se observaron capturas de mayor talla para la especie “talag queenfish” (Scomberoides commersonnianus), mientras que para el curricán fueron la caballa o verdel (Scomberomorus commerson), barracuda (Sphyraena jello), e “Indian threadfish” (Alectis indicus). En conclusión, la implementación de medidas técnicas, como restricciones en las artes de pesca, podrían ser aplicadas en la regulación de la normativa de pesca recreativa para la gestión general pesquera con el objetivo de la mejora en los patrones de explotación especie-específica del golfo de Omán

Length-weight and length-length relationships, condition factors and optimal length of some fish species from the Persian Gulf and Oman Sea

Length-weight relationships (LWRs), relative condition factor (Krel), relative weight (Wr) and optimal length (Lopt) were calculated for five important commercial fishes from Iranian waters of the Persian Gulf and Oman Sea. Samples were collected from 2011 and December 2012 in 11 stations in three Iranian provinces (Hormuzgan, Khozestan and Sistan and baluchestan) using trawl and gillnets. Also, length-length relationships (LLRs) for Pampus argenteus and Scomberomorus commerson were computed. The values of the exponent b in the length-weight relationship ranged from 2.593 for S. commerson to 2.995 for P. argenteus. Krel varied between 1.01 ± 0.08 for Parastromateus niger and 1.06 ± 0.41 for P. argenteus. Also, Wr ranged from 59.12 ± 47.74% for S. commerson to 107.78 ± 107.29% for Eleutheronema tetradactylum. The Lopt were calculated for all five species. A negative allometric growth was found in S. commerson, while other four species (E. tetradactylum, Otolithes ruber, P. niger and P. argenteus) had isometric growth. The length-weight and length-length relationships presented here are for the first time in the Iranian coastal waters of the Persian Gulf and Oman Sea, which can provide a basis for fisheries management

Effect of hook and bait size on catch efficiency in the Persian Gulf recreational fisheries

The effect of hook and bait sizes on the catch efficiency and size composition of Spangled Emperor Lethrinus nebulosus, Orange‐spotted Grouper Epinephelus coioides, and Narrowbarred Mackerel Scomberomorus commerson was investigated in the recreational and semi‐subsistence handline fishery in the Persian Gulf. Based on expectations that increasing hook and bait sizes would decrease the catch efficiency of the smaller individuals while maintaining the catch efficiency of larger fish, we investigated the effect of increasing hook and bait sizes. For all three species, the results indicated slightly lower catch efficiency for the smaller fish when larger hooks were used. Furthermore, the results demonstrated a significant increase in catch efficiency for the larger sizes of Spangled Emperor and Orange‐spotted Grouper when fished with larger hooks, an effect that increased with fish size for both species. Additionally, the overall catch efficiency did not vary significantly when increasing hook and bait sizes for the three species investigated. This study shows that fishing with larger hooks and larger bait would change the exploitation pattern of these species toward higher proportions of larger fish in the catches. Moreover, based on the size distribution of the species on the fishing grounds during the study period, the use of larger hooks and bait would lead to significant increases in the total number of Spangled Emperor caught (41% increase; 95% confidence interval [CI] = 17–69%) and the total number of Orange‐spotted Grouper caught (151% increase; 95% CI = 132–336%), respectively. The results indicated a similar effect for Narrowbarred Mackerel; however, the effect was far less profound than for the two other species and was not significant for any size‐classes

The effect of depth variation on size and catch rate of green tiger shrimp, Penaeus semisulcatus (De Haan, 1884) in Bushehr coastal waters, Northern Persian Gulf

Catch data of Penaeus semisulcatus were collected for three years (2009-2011) during the period of June to August to estimate the effect of depth variation on length frequency and catch rate (Kg h-1) of the species. No difference was observed between the shallow and deeper catch rate (ANOVA test, P &gt; 0.05). However, the size composition of green tiger shrimp were affected by depth variation (Kolmogorov-Smirnov test, P &lt; 0.05) and were positively correlated with depth (P &lt; 0.05 and r = 0.140). The smaller individuals prefer shallow waters, indicating behaviour differences between the juveniles and adults of this species. The positive correlation between size of shrimp and water depth can be attributed to the behaviour predation.Keywords: Green tiger shrimp, Penaeus semisulcatus, catch rate, depth variation, Persian GulfAfrican Journal of Biotechnology Vol. 12(20), pp. 3058-306

Study on different hook and bait types in the Persian Gulf hand line fishery: optimization and development

The hand line fishery in the Persian Gulf is considered a sustainable fishing practice. The aims of this study were to estimate catch composition, catch rates, length frequencies, and the percentage of individuals caught below length-at-maturity with two types of hooks, circle and J-style with natural and artificial bait by hand line fishing. Circle and J-style hooks with natural and artificial bait were alternated. Sampling operations were carried out on Qeshm Island, in the North of the Persian Gulf in spring 2015. Catch per unit effort for J-hooks with natural and artificial bait and circle hooks with natural and artificial bait differed significantly (p  0.05). For most species (except L. nebulosus), there was no significant difference between circle and J-style hooks for the proportion of individuals smaller than length-at-maturity (p > 0.05)

The catch composition of the beach seine fishery in southeast of the Caspian Sea (Case study: Golestan Province)

The beach seine fishery is performed regularly along Iranian coasts of the Caspian Sea. The aim of the present study was to determinate of the species composition of beach seine fishery in Golestan Province. Due to the extent of fisheries cooperatives in the study area 7 cooperatives was selected, namely Magtymguly, Niyaz Abad, Yashar, Shayan Aydin, Golestan, Charqly, Norgolestan and Nemune. Sampling was done weekly basis from late September 2009 to late April 2010. The beach seine nets used in this fishing area were 1200m long and mesh size was 30 to 33mm (Bar length). A total of 462680 Kg teleost fish were caught during the 1534 hauls. The CPUE of teleost fish was 298.8 Kg among the selected cooperatives. The highest and lowest CPUE was observed in Yashar (with 207.5 Kg) and Norgolestan cooperatives (462.4 Kg). Data analyses indicate that Golden grey mullet (with 52.6%) and Roach (with 0.02%) have the highest and lowest proportion of total teleost fish catch. The catch composition did not differ significantly between different months (Chi-square test, P>0.05). In Golden grey mullet, Kutum and Common carp 70.75%, 49.36% and 73.68% of specimens caught were larger than fishing standard size respectively, but in Persian sturgeon 96% of fish captured was smaller than fishing standard size. Results of one sample t test showed that mean length of caught target species, except Kutum, have differ significantly with their Lm 50. In the last decade, catch amount of teleost fish have fluctuated and it was lowest in 2009. It could be managed by making regulations for improving fishing selectivity (such as mesh size and other equipment of fishing gears), more prohibition of spatial and temporal fishing, etc

Length-weight and length-length relationships, condition factors and optimal length of some fish species from the Persian Gulf and Oman Sea

Length-weight relationships (LWRs), relative condition factor (Krel), relative weight (Wr) and optimal length (Lopt) were calculated for five important commercial fishes from Iranian waters of the Persian Gulf and Oman Sea. Samples were collected from 2011 and December 2012 in 11 stations in three Iranian provinces (Hormuzgan, Khozestan and Sistan and baluchestan) using trawl and gillnets. Also, length-length relationships (LLRs) for Pampus argenteus and Scomberomorus commerson were computed. The values of the exponent b in the length-weight relationship ranged from 2.593 for S. commerson to 2.995 for P. argenteus. Krel varied between 1.01 ± 0.08 for Parastromateus niger and 1.06 ± 0.41 for P. argenteus. Also, Wr ranged from 59.12 ± 47.74% for S. commerson to 107.78 ± 107.29% for Eleutheronema tetradactylum. The Lopt were calculated for all five species. A negative allometric growth was found in S. commerson, while other four species (E. tetradactylum, Otolithes ruber, P. niger and P. argenteus) had isometric growth. The length-weight and length-length relationships presented here are for the first time in the Iranian coastal waters of the Persian Gulf and Oman Sea, which can provide a basis for fisheries management

Study on some population dynamics parameters of Sardinella sindensis (Day, 1878) in Coastal waters of Jask Province

Sind sardine Sardinella sindensis (Day, 1878) is the most important ecological and commercial surface resources in Persian Gulf and Oman sea. This study was carried to study some population dynamics parameters of Sind sardine in Coastal waters of Jask Province during January 2011 to December 2012. A totall 2887 specimens were collected from commercial fishing Purse seiners, monthly. Biometric parameters were measured. The mean length and weight were 14 cm, 29 g respectively and the most dominated length group was 14-15 cm (24.7%). The Von Bertalanffy growth parameters were calculated as L=19.5 (cm), k=1.18 (year-1), t0 = -0.18. Weight- length relationship showed an isometric growth and it was W = aL3.0522 (r2= 0.9432). The natural (M), fishing (F) and total (Z) mortality were 2.19, 0.87 and 3.06 per year respectively. The exploitation rate (E) was 0.29

The catch per unit of effort catch per unit of swept area and biomass of Threadfin Bream (Nemipterus japonicus) by swept area method in coastal waters of bushehr province

The aim of this study was to investigate and estimate the CPUE (Catch Per Unit of Effort), CPUA (Catch Per Unit of Swept Area), biomass and length frequency of Threadfin Bream (Nemipterus japonicus) in Coastal waters of Bushehr. This study was carried out in March 2011. The study area was divided into three area (Northern, Central and Southern) and depth zones (10-20, 20-30 and 30-50 m) and stratified random sampling was used to collect data. The sampling data was collected from 41 stations. The forked length of Nemipterus japonicas was ranged from 14 to 29 cm and the average forked length was calculated 20.29±2.64. Total CPUE and biomass of Nemipterus japonicas were calculated 16259 tonnes and 1771 kg/hours, respectively. The minimum and maximum CPUE were observed in 20-30 m depth zone (169.1 kg/hours) and 30-50 depth zone (1370.8 kg/hours), respectively. Total CPUA of Nemipterus japonicus was calculated 19678.8 kg/nm2. The minimum and maximum CPUA were observed in 10-20 m depth zone with 4.1 kg/nm2 and 30-50 m depth zone with 2147.7 kg/nm2, respectively. The results showed that the most abundance of Nemipterus japonicus was in higher than 30 m depth zones in Bushehr waters