جستجوی مقالات مرتبط با کلیدواژه « catch composition » در نشریات گروه « شیلات »

The purpose of this research was to investigate the catch composition and length frequency of S. putnamae using Four meshe sizes of 64, 83, 95 and 110 mm in gillnet in the February (winter) and June (Summer) 2022, in the coastal waters of Sistan and Baluchistan province. In the Sampling period, 22 species were caught, in the summer season, the highest catch rate was 33.04% for the S. putnamae and P. pelagicus was the least caught with 0.37% , and in the winter season, S. putnamae was the most caught with 35.68% and T. croaker the lowest catch rate of 0.31%. Also, The rate of by-catch was 17.10%, A. thalassinus the highest percentage of by-catch. The highest length frequency with 52.8% for 83 mm mesh size in the summer and the highest length with 57.2% for 95 mm mesh size obtained in winter. the comparison of the length frequency of S. putnamae caught by different mesh sizes in summer and winter season and the average length of S. putnamae in the different mesh sizes showed that there is a significant difference between them. Also, the comparison between the mesh sizes showed that the 83 mm mesh size in summer and the 95 mm mesh size in winter had a significant difference with the size of other and similar mesh size in other seasons. The results showed that more fish were Snagged in smaller mesh size and more fish were Gilled in larger mesh size.

The objective of the present study was to determine the effects of fish aggregation device (FAD) deployment on biodiversity, catch composition and length frequency distribution in the Qeshm Island handline fishery. Two FADs were deployed in the Qeshm Island. Four biodiversity indices including Margalef, Shannon-Weaver, Simpson and Pielou and also catch composition and length frequency distribution were calculated and compared between FAD and non-FAD area among spring and fall seasons. Comparing catch composition between FAD and non-FAD area by simper analysis showed that Scomberoides commersonnianus, Acanthopagrus latus, Scomberomorus commerson, Argyrops spinifer, Nemipterus japonicas and Caranx sexfasciatus were responsible for 78.03 dissimilarity. However, Comparing catch composition between spring and fall seasons indicate that A. spinifer, C. sexfasciatus, Netuma thalassina, S. commerson N, japonicas and Pomadasys kaakan were responsible for 82.77 dissimilarity. Length frequency distribution of all species (except P. kaakan) was differed significantly between FAD and non-FAD area (P<0.05). All of the biodiversity indices were lower significantly around the FAD area (P<0.05). But no significant difference was found in biodiversity indices between spring and fall seasons (P>0.05). In other mean, limited species comprise the catch dominantly. Quantifying biodiversity on the basis of diversity indices is essential both for sustainable development policies and for addressing ecological issues, such as the relationship between biodiversity and ecosystem functions.

For study CPUE, Catch composition and length frequency in surface narrow-barred Spanish mackerel gill net (Costal region of Sistan Va Baluchistan Province), a study was done in 6 fishing grounds in four months. 778 specimens belong to 25 species was catch and identified. Tuna fish (Auxis rochei rochei) with 135 specimens and 100% probability in all sampling places, is the large number and Nemipterus japonicus, Rachecentron Canadum and Epinephelus coioides with 3 species and 33% probability are the lowest number. Also, Sphyraena putnamiae with weight average of 3672 gr, has maximum weight and Acanthopagrus cuvieri with 271.4 gr has minimum weight.

Multispecies fishing is one of the traditional pots characteristics (Gargoor). The aim of this study was comparison of bait types (sardine, cuttlefish and catfish) and the bait shapes (pieces and minced), and their effects on catch composition, using eighty-four Gargoors (14 treatments and 6 replicates) in 2 stations located near-shore (4 miles) and off-shore (11 miles) of Gasheh beach (Lengeh Port) with soaking time of 24 hours. Results showed that the bait types had significant effect on frequency of Epinephelus coioides, Pinjalo pinjalo, Lutjanus johnii, Pomadasys Kaakan, Otolithes ruber and Argyrops spinifer. Epinephelus coioides had the highest frequency in both stations. The highest catch frequency was observed for cuttlefish and sardine baits and the lowest was observed for catfish bait. Regarding the comparison of biodiversity indices, Margalef index (D) revealed no significant difference among seasons in both stations. Evenness index (J) showed significant difference among seasons only in near-shore station, but for Shannon index (H’) significant difference was observed among seasons in both stations. Consequently, sardine in spring and cuttlefish in winter as bait had the best efficiency. In addition, because of low efficiency, using of catfish as bait is not recommended.

Biomass, Catch per Unit of Area (CPUA), distribution and catch composition of Bottom Trawl demersal resources from Oman Sea (Sistan and Balochestan province coastal waters) were investigated in this study. Data were collected in one research cruise by using R/V Ferdows-1 during 2016. The study area was stratified into 5 strata (M to Q) and 4 Substratum covering the depths of 10- 20, 20-30, 30-50 and 50-100 m in the Oman Sea. A total of 92 stations were selected in a random stratified design distributed in different depths and area. The swept are method was used to access and estimate the amount of biomass and CPUA. Result indicated that the percentage of density of demersal resources in the M Stratum (Biahi to Galak estuary) and Stratum Q (Bersi to Gwatr) had the highest value of biomass and CPUA. Also depths of 10-20 m had lowest value CPUA and biomass of commercial, non-commercial and total species. The amount of biomass in depth of 50-100 m was 4.1 times higher than that of depth 10-20m. Maximum CPUA of commercial, non-commercial and total species was estimated in strata M, M and Q and M respectively. Aroun100 species were identified in this study; the results of the study suggest that high density of commercial species distribution concentrated in West-coast, while non-commercial resources observed in East coast of Sistan and Balochestan province. The Result of this study is beneficial for objective management of Demersal Resources exploitation in Oman Sea.

Although there is no much information about shrimp industrial trawler, the aim of this study was to estimate the catch composition and Catch per Unit of Area (CPUA) of Penaeid shrimps from the bottom trawls of Bushehr coastal waters. Sampling was carried out by stratified sampling producer in the three strata: <10 m, 10-20 m and 20-30 m. The catch composition included: 95.93% Green tiger shrimp (Penaeus semisulcatus), 3.17% Jinga shrimp (Metapenaeus affinis), 0.37% Peregrine shrimp (Metapenaeus stebbingi), 0.37% Kiddi shrimp (Parapenaeopsis stylifera) and 0.18% Fiddler shrimp (Metapenaeopsis stridulans) during the 44 haul. The overall CPUA index for shrimp was 98.51±153.22 g/km2 in Bushehr coastal waters. Green tiger shrimp (P. semisulcatus) with 94.5±151.9 g/km2 was the dominated species and its distribution was significantly different between the north and south fishing grounds (P<0.05). One-way ANOVA test showed a significant difference between the CPUA index of different shrimp species (P<0.05). Also, the CPUA index was computed for each species from all the strata and the Two-way ANOVA test indicated no interaction between the depths and the shrimp species (P>0.05).

Study of longline's was carried out to identify the catch composition on the Persian Gulf water. The study areas were from Arvand-Rod to Musa- Khor. Sampling was carried out in three season’s spring, summer and autumn (9 mounths) on a cruise through out month.Twelve specie were caught and indentified. catch composition consisted of Acanthopagrus latus (Houttuyn, 1782), Acanthopugrus bifasciatus (Forsskål, 1775), Lethrinus nebulosus (Forsskål, 1775), Rachycentron canadum (Linnaeus, 1766), Epinephelus coioides (Hamilton, 1822), Pomadasys kaakan (Cuvier, 1830), Diagramma pictum (Thunberg 1792), Acanthopagrus cuvieri (Day 1875), Arius thalassinus (Rüppell, 1837), Carcharhinus sorrah (Müller & Henle, 1839), Rhynchobatusdjiddensis (Forsskål, 1775), Pastinachussephen (Forsskål, 1775). The grouper (Epinephelus coioides) and cobia (Rachycentron Canadum) were respectively accounted for the highest (24.19) and smallest (1.47) percentage of the fishing. Thisstudy reveals that thesize of fish and the depth have a positive relation ship.