Estimation of MSY on six species of commercially important demersal fishes in the Persian Gulf & Oman Sea (Hormuzgan province)

Today, calculation of MSY is one of the necessary fisheries management in control and prevention of the fish population reduction and is obtained with different methods. This study has focused on six species of commercial fish, including Tiger-toothed croaker, Javelin grunter, John`s snapper, Indian spiny turbot, Yellowfin seabream and Silver pomfret. The study was done monthly, from January 2007 to March 2008, in three fish landing regions including: Bandar Lengeh, Bandar Abbas and Qeshm Island (Slakh, Basydu and Chahoshrqy). Total 5163 Silver pomfret (Pompus argenteus), 1766 Javelin grunter (Pomadasys kaakan), 2151 John`s snapper (Lutjanus johnii), 3280 Tiger-toothed croaker (Otolithes ruber), 1628 Indian spiny turbot (Psettodes erumei) and the number of 759 Yellowfin seabream (Acnthopagrus latus) were assessed and length biometry has been done, monthly. In this study, two methods were used to determine the maximum sustainable yield (MSY): 1- virtual population analysis (Cohort analysis) 2- use of statistics and information that was estimated with two method, catch prediction and biomass (Standing stock). The results showed that in 2007, MSY value was estimated through catch prediction for Silver pomfret, Tigertoothed croaker, Javelin grunter, John`s snapper, Indian spiny turbot and Yellowfin seabream 1354, 1116, 1099.6, 1045.5, 914.5 and 529.5 tons, respectively. Moreover, this estimation have been done through standing stock for Silver pomfret, Tiger-toothed croaker, Javelin grunter, John`s snapper, Indian spiny turbot and Yellowfin seabream 1215, 633, 1304, 878, 1095 and 441 tons, respectively; and through VPA for Silver pomfret, Tiger-toothed croaker, Javelin grunter, John`s snapper, Indian spiny turbot and Yellowfin seabream 1100, 850, 920, 732.5, 1002.3 and 403 tons, respectively. Amount of biomass (Standing Stock) was estimated for Silver pomfret, Tiger-toothed croaker, Javelin grunter, John`s snapper, Indian spiny turbot and Yellowfin seabream 2530, 1172, 1738, 1689, 1470 and 1110 tons, respectively. In general, by assessing the obtained results for the studied species, except the fishing prediction results of the Javelin grunter and Tiger-toothed croaker species, which is less valuable due to the low correlation coefficient, it can be stated that except fishing pressure on John`s snapper and Tiger-toothed croaker, in other species studied, fishing conditions are in optimal situation

Investigation of two crop culture of western white shrimp

Two crop culture of western white shrimp with 2 treatments and 2 replicates in each treatments in earthen ponds with area 0.4 hectares at a density of 20 pl 18 in each square meter were done. For the culture of shrimp in the second stage, the post larvae cultured in nursery pond with area of 0.25 hectare, and density of 96 post larvae in each square meter, and then transfer to the rearing ponds. In each pond, 2 aerators with potency of 3 horsepower fixed. Every day horsepower clarified at 21p.m. to 23 p.m and out at 6 a.m to 7 a.m. The first stage of culture begun in 19 April with pl 18. The yield pick-up after 96 days. The stocking of pl in the nursery ponds was done in 25 July with pl16 and after 38 days hunted and transferred to second stage culture. The second culture was done in 1 September and pick-up after 65 days. For feeding of shrimps we used commercial food numbers 4001 until 4006. In the first mount the feeding of shrimps were done as blind feed and then with the shrimps biomass and with research of feeding trays. Water temperature, dissolved oxygen and pH daily in 2 times at the morning (6 a.m) and evening (at 15 p.m) and the salinity, transparency and water depth 1 time daily measured. In the first culture period (96 days), the mean weight, length, daily weight gain, FCR, survival percent shrimp production were 14.03 gr, 12.08 cm, 0.15 gr, 1.02 gr, 92 percent and 2132 kilograms and in the second culture period (65 days) 14.55 gr, 12.48 cm, 0.22 gr, 0.84, 73 percent and 2675 kilogarms measuered respectively. Totally, in the second period culture the initial weight of shrimps was higher than the first period culture 1.95 gr and 0.008 gr respectively, therefore growth indexes in the second period were better than the first culture period. Coefficient of determination of weight and lenth of shrimps with increase of cultue days, in the first and second culture periods, in the total cases the number were higher than 0.97. This shown that the role of increase of days on the increase of weight and lenth is higher than 97 percent. Also, determination of product moment, showed that there is very strong correlation between increase of days and increase of weight and lenth and between weight and lenth (0.97 to 0.99)

Determination of biotechniqe and bionormative of breeding and culturing of Penaeus merguiensis de Man in Bushehr Area

To introduce the native commercial shrimp species to aquaculture industry, the Iranian Fisheries Research Organization conducted a project to investigate the possibility of reproduction and cultivation of the banana shrimp (Penaeus merguensis). The present work has been carried out from 21st March 2001 in two phase, reproduction and cultivation, in Iran Shrimp Research Center. The main objectives of this study was to find the possibility of reproduction and cultivation of banana shrimp with emphasis on its cost and benefit and to find if this species could be introduced to aquaculture industry in Iran. In this work, 42 brood stocks of banana shrimp caught in Jask waters and were transported to Bushehr. The shrimps were reproduced in aquaculture research station, and then cultivated in 0.4 ha ponds in Heleh region. Most of the broodstocks perished, due to long distance of Jask from Bushehr province, or had problem in hatching. Finally 8 of broodstock shrimps spawned. In 3 cases, the reared naplii larva suffered high mortality, but the other 5 spawner’s bread successfully. The post larvae were introduced to the shrimp ponds. The primary stocking was 360,000 larvae, introduced to each of two 4 m 3 tanks. The survival in both tanks for mysis stage was 83% but for PL stages, the survival was 5% for Tank 1 due to disease outbreak (until PL 24), and 62% for Tank 2. On 10 th June 2001 the PL 24 were stocked into the ponds but unfortunately due to adaptation problem, all of the shrimps perished. It seems that banana shrimp couldn’t to be adapted to the pond condition in Heleh region. On the basis of the results, the reproduction of the banana shrimps is achievable, but broodstocks needs to be transferred to reproduction areas as soon as possible to reduce stress on the shrimps. Our finding shows that the optimum conditions of salinity and temperature for growth of the reared banana shrimp in Heleh region is 33ppt and 30 °C, respectively

Investigating the application of spawning shelter of cattle fish for its enhancement of resources

In this project, four types of structures, of 40 number was investigated. In a six month period, the structures were inspected 13 times. The total weight and number of eggs hatched on the structures were estimated to be 214.1kg and 94944 respectively. The weight and number of eggs settled on trap types were 141.9 and 60982 respectively, whereas, The eggs on cubical structures were estimated 56.7kg and 27088 ,on pyramid structures 7.9 and 3941 and then also were 6.9 kg and 3280 eggs on cylindrical structures respectively. It is also estimated that 358 eggs were settled on The connecting line weighting 0.5kg. In this report four types of structures was compared. As a result, the trap, cubical, pyramid and cylindrical structures had contributed to the settelment of 66, 27, 4 and 3 percent of eggs in weight. While 64, 29, 4 and 3 percent of eggs in number was settled on these structures respectively. Thus it is concluded that the trap structures fallowed by cubical ones had acted more effectively relative to other two. If based on the results of other studies, we assume 80% survival rate of eggs and average weight of 1.2 kg of survival growth cuttlefish, then it can be calculated that 160 structures can contribute to 91 tons increase in cuttlefish stock in one area of 4 to 5 acre. It is obvious that by planning an annual increase of the structures, it is possible to attract more spawners to spawn and produce more larvae. Moreover,The old structures will be covered by corals and barnacles and become Amore stalie and attractive spawning ground for cuttlefish

Evaluation of the large pelagic fishes (Scomberidae family) for optimum exploitation level in the Persian Gulf

Reproductive biology, Diet and population dynamics parameters of narrow-barred Spanish mackerel, Scomberomorus commerson, in the Persian Gulf were studied during 2011-2012. Fork length frequencies were collected from the commercial catch and from the current fishery nets (gill nets with 9 and 14cm mesh size) at the landing places. During 5 periods in October, December, March, April and July 20-40 specimens were also purchased from the fishermen at several landing sites to investigate and recording of data for feeding and reproductive conditions. Fork length (FL) of 2742 fishes was recorded to the nearest cm and weight of the specimens were measured to the nearest 0.01kg. FiSAT program was used to assess growth and mortality parameters. Reproductive maturity stages were assessed macroscopically using a five element scheme based on gonad size and appearance. The numbers of ovaries were fixed and preserved in 10% formalin. Central sections were embedded in wax, sectioned Hematoxylin–Eosin stains. For this subset, gonad maturation was categorized histological using a simplified five-stage description scheme and compared with the macroscopic assessments for validation. A Gonosomatic index (GSI) was also calculated for each fish. Feeding condition results showed that, sardines are the major prey of S. commerson. Pony fishes, Haltbeak and Indian mackerel were observed in the stomach content. These preys can be assumed as a secondary or accidental food items. Liver Somatic Index (HSI) was maximum in April and minimum in July. The annual instantaneous rate of fishing mortality (F= 0.42 year^−1) was considerably greater than the target (Fopt= 0.28) and limit (Flimit= 0.37) biological reference points, suggesting that the stock is heavily overexploited. Feeding and nutrition results showed that sardines are the major items prey of king S. commerson. Ponyfish, haltbeak and Indian mackerel fishes were observed in diet that can be considered as secondary or accidental foods. Maximum and minimum of Kn index was in October (9.3) and in March respectively. Liver Somatic Index (HSI) was the highest rate in February (1.70) and the lowest in July (0.85) that indicated on the worst and the best condition of fish in the mentioned periods respectively. No difference was observed in the weight stomach index and weight index (SI) in two sexes and it was about 0.09. The smallest of fish was observed 17cm FL and the biggest was 152cm FL. The mean size of fork length frequency was observed from maximum108cm (SD= 24) in February to minimum 29.4cm (SD= 5.5) in September. Based on growth curve analysis, growth parameters, K and L_∞ were estimated 0.23year^−1 and 156.45 cm respectively. Instantaneous total mortality (Z), was 1.13 year^−1 . The estimate of M was 0.43 year^−1 and thus, the estimate of F was0.7 year^−1 . This translates to an exploitation rate (F/Z) of 0.69 year^−1 . Target (Fopt) and limit (Flimit) biological reference points were calculated 0.17 year^−1 and 0.22 year^−1 respectively. The size at capture at a probability of 0.25 (L25), 0.5 (L.5) and 0.75 (L.75) was35.84 cm, 40.28cm and 61.98 cm respectively. Tmax was calculated as 3/K equal to 6 years. Matured females (Stages III, IV) were observed between mostly between April to July. By July, most fishes were in ripped and spent stages (StagesIV, V) indicating the end of the spawning season. The result of GSI avtivity in 153 male and female fish indicated the highest reproductive activity from April to July with the peak of July. The present study results shows that the highest of catch rate were done in 1 and 2 years olds of fish. Although exploitation rate have not indicated over fishing but Fopt and Flimit rates are less than fishing mortality that shows overexploitation was happened. Changes of the mesh size in the gillnet of 9cm and the size of the nets should be considered. Banning of the king mackerel catch in the June and July that is the spawning peak period can be helped to the brood stocks

Efficiency of shrimp trawl nets polyamide and polyethylene with standard mesh in the coastal waters of Bushehr Province

This study was carried out in August – september 2009 in Bushehr province waters. Two different shrimp bottom trawls were used in which were woven by Poly Amid and Poly Ethylene with mesh sizes (stretched) of 50 mm and sack with 35 mm. Also 2 different vessels of two dhows and one steel ship each with 26 and 30 hauls were used and taken in to comparison from point of obtained results. Total catch of PA and PE trawels were 4592 and 5535 kg of which the ratio of shrimp catch and by catch for PA trawl was 32.4 and 67.6 % respectively; and for PE trawl was 34.2 and 65.8%. Total catch of PA and PE trawls of steel trawler ( ship ) were estimated 3158.0 and 4784.7 kg, respectively, of which the shrimp/ bycatch ratio was 6.6 : 93.4%. There was a higher amount of bycatch for PE comparing to PA trawl (p<0.05). on the other hand the decrease of shrimp and bycatch for PA comparing to PE dhow trawlers were 21.3 and 15.0% and for ship were 34.6 and 34.0% respectively. The weight ratio is 1:15 i.e . in PE ship trawl, in proportion to on kg shrimp, 15 kg bycatch was harvested. it is proposed to standardize the mesh size and also to do obligtory the instal of squared mesh size panel

Development gene data bank of cultured shrimp species in Iran

DNA barcode is a short, standard well known sequence of cytochrome oxidase І gene. By using this DNA sequence can be realized that each animal, plant or fungus belongs to which species. in this research, samples were collected from imported cultured shrimp Litopenaeus vannamei and and 6 Persian Gulf and Oman Sea shrimp species which classified based on traditional systematically as: Penaeus semisulcatus, Fenneropenaeus merguiensis, Metapenaeus affinis, Parapenaeopsis Stylifera and Fenneropenaeus indicus. After examination of DNA barcode sequence, molecular and bioinformatics operations of each sequence in the Consortium for the Barcode of Life (CBOL) and National Center for Biotechnology Information (NCBI), phylogenetic analysis of each sample was determined and similarity of each sample with NCBI and CBOL database was checked and the closest species to each sample were specified. According to the results different samples of L. vannamei, . banded P.semisulcatus, F. merguiensis and F. indicus have more than 97% similarity to the same species of other countries. non banded P.semisulcatus had 80.07% similarity to banded P.semisulcatus, M. affinis samples had 90.3% similarity to Metapenaeus ensis and Parap. Stylifera had 93.44% similarity to Parapenaeopsis coromandelica in the CBOL. This funding confirmed the need for further investigation and possible announcement of new species

Biomass estimation of demersal resources in the Persian Gulf and Oman Sea by Swept Area Method

Regarding to monitor of demersal resources in the Persian Gulf and Oman Sea, and also biomass and CPUA estimation of them, a series of research cruises (5 cruises per year) were carried out by R/V Ferdows-1covering the area from 49 00 E in the west (Khoozestan provice) to 61 25 E in the east (Gwater) in a 5 years program form 2004 up to 2008 (no cruise in 2006). The study area was stratified into 17 strata (A to Q) of which 10 starta (A to J) were in the Persian Gulf and 7 strata (K to Q) were in the Oman Sea, covering the depths of 10-50m in the Persian Gulf and 10-100m in the Oman Sea. A total of 316 stations were randomly selected. The biomass and CPUA were estimated by Swept Area method. The comparison between two regions indicated that the percentage of density of demersal fishes in the Persian Gulf during years 2004, 2005, 2007 and 2008 were 3.3, 3.9, 2.3 and 2.4 times more than the Oman Sea and totally 70-80% of total biomass was calculated for the Persian Gulf. Also a comparison among 17 starta, the highest biomass was found for starta C & D in the Bushehr province waters. The amount of CPUA for both regions of the Persian Gulf and Oman Sea was compared and it was concluded that in years 2004 and 2005, the mean CPUA in the Persian Gulf was partially higher than the Oman Sea with 1.06 & 1.20 times more; and on the contrary for the next two years this value was higher in the Oman Sea with 1.3 times more. The highest CPUA of demersal resources for the Oman Sea belonged to the strata K & O for years 2004, 2007 and 2008 and for year 2005 was for L and strata. It can be concluded that the north-west of Oman Sea has the best condition of biomass of commercial and non-commercial species and the O stratum will be in the second ranking. With review the mean CPUA in different depth-layers for years 2004, 2005, 2007 and 2008, it was concluded that with increasing the depth, the mean CPUA is decreased in which the CPUA values in depth-layer 10-20m for these years were 8.3, 3.0, 2.1 & 1.6 times more than depth-layer 50-100m. The comparison of mean CPUA for 10 strata of the Persian Gulf showed that in years 2004 and 2005, the mean CPUA of demersal fishes in the Hormuzgan province waters was higher than in Bushehr province waters (1.2 times more). In total, the highest maen CPUA belonged to F (Naiband to Mogham) and G (Mogham to Farour) in Hormuzgan waters. On the contrary, in years 2007 and 2008 this value in Bushehr waters was 1.3 times higher than western part of Hormuzgan waters with the highest value in D stratum(Boordekhoon to Dayyer). Also the comparison of mean CPUA for different depth-layers, it was found that the mean CPUA has ascending trend with increasing the depth, with the highest value in depth-laer of 30-50m in which contains the 55-68% of total biomass. The lowest biomass is found in depth-layers of 10-30m. Totally, the minimum CPUA and biomass for both commercial and non-commercial species belonged to a stratum located in Khouzestan province waters and it was shown the over-exploitation of resources in this area. The comparison between commercial and non-commercial groups in both ecosystems , it was concluded that the density of commercial species was higher than non-commercial ones , and in all years the Persian Gulf indicated higher values than the Oman Sea

Stock enhancement and estimation of growth rate of green tiger prawn (Penaeus semisulcatus) and banana shrimp (Fenneropenaeus merguiensis) released in the Persian Gulf

Present study was conducted in the Persian Gulf (Iranian waters) from 2009 to 2012. The main objective of the research was economical evalution of the stock enhancement of banana prawn (Fenneropenaeus merguiensis) and green tiger shrimp (Penaeus semisulcatus) in the studied area. Also tagging effects on the growth and mortality of tagged shrimp were studied. In banana prawn, broodstock shrimps were hatched in June. In July 2010 and 2011some of the juvenile of this species were marked by red fluorescent liquid injection and released were made at night in the estuaries of Tiab, Kolahi and Koolgan in the Hormozgan province. 84000 juveniles of banana prawn in 2010 and about 50000 in 2011 were released in this area. In Bushehr province waters, adults shrimp were reared and when juveniles reached to optimum size, some of them were tagged by red and blue coloures and were released in the coastal waters of Bandargah and Delvar. Tagging and releasing program of green tiger prawn was performed in 2010 and 2012. A total number of 8000 prawn in 2010 and about 30000 juveniles prawn in 2010 were released. Activities for recaptured shrimps were informed by posters describing the tagging program that were distributed to local peoples, as well as local magazines, and a tagging program awareness film was broadcast on national television three times prior to the shrimp fishing season and during catch season. To encourage people to report recaptures a reward of two handered thousent riales was paid for the return of each marked shrimp accompanied by information. Economical evaluation of banana prawn was performed based on releasing and recaptured program in 2011. As it mentioned in this year 50000 of juvenile shrimp were tagged and released. At the same time 4700000 of unmarked shrimp were released in this area. In the shrimp season 11 (./022%) of tagged shrimp were recaptured. Movements of tagged shrimp were northwesterly to released area. Weight average of tagged prawns was 1.2 gram. Mean weight of the recaptured prawns was 22.06±4.9 gram. Body weight Growth of the recaptured prawns was between 16-26 grams with the growth speed of 0.88-1.41 per week. The number of recaptured prawn to the released prawn was 0.022 percent. Based on the released prawns (4700000) to the recaptured percent (./022%), about 103400 of released shrimp with mean weight of 2.5 tones were observed in the Hormozgan shrimp catch. The average price of shrimp in the studied year in the local market was 85000 Rials per kilogram. These results showed that the ratio of profit is 210 milion riales. In the taggiing program of green tiger prawn in the Bushehr waters only one recaptured shrimp was observed in the catch season (2012). Total weigth and total length of this prawn was 99 gram and 22 centimeter respectively .given the small percentage of the recaptured, economical analyses was not performed on this species. The effects of tagging on the growth and mortality of green tiger prawn were studied. The present study was carried out in the shrimp research station in Bandargah and Abzistan shrimp Hatchery Company in Delvar during 2010 and 2012. The accuracy of the study was more rialable in 2012. In this year growth and mortality of juveniles that was marked by red and blue coloures, were studied in both area Bandargah and Delvar. In Bandargah, three tanks of 300 l each with 30 specimens were used for untagged shrimp as a control group, and tagged with injected liquid fluorescent during 98 days. Length and weigh of 10 specimens were measured evenly in different times. ANOVA results (α = 0.1 and α = 0.5) showed no significant differences between length growth of tagged shrimp and control group. The mortality of two groups was evaluated by numbering of remained shrimps and the average of survival was 52 percent in the tagged and 44.5 percent in tagged shrimps. In the Delvar station, Abzistan Company, the specimens were kept in the 9 tanks each 300 l that included of 30 untagged shrimps, 30 blue tagged shrimps and 30 red florescent tagged shrimp. The growth and mortality of this station were evaluated during 110 days. The growth rate of the specimens were measured and recorded evenly. The results of ANOVA (α = 0.1 and α = 0.5) showed no difference significantly in the weight growth of tagged and control groups. The mortality rates among the control group, red tagged and blue tagged were 63 percent, 59 percent and 40 percent. The mortality of the groups was differences in the two stations and it seems the management and environmental conditions were more affected on the mortalities. The results of the study show that the ratio of profit to the coast is 0.46 that is covering half of the coasts, so that the expenditures are two times more than profit. This result is the minimum of economical value of stock enhancement of shrimp. The results of study showed that the injected tags into the body tissue of shrimp has no affected on the growth rate and mortality

Biomass estimation of demersal resources in the Persian Gulf and Oman Sea by swept area method

Regarding to monitor of demersal resources in the Persian Gulf and Oman Sea, and also biomass and CPUA estimation of them, ten research cruises were carried out by using R/V Ferdows-1 equipped with bottom trawl, covering the area from 49º 00´ E in the west (north-west Persian Gulf) to 61º 25´ E in the east (borderline with Pakistan) from 2012 to 2014 The study area was stratified into 17 strata (A to Q) of which 10 strata (A to J) were in the Persian Gulf and 7 strata (K to Q) were in the Oman Sea, covering the depths of 10-50 m in the Persian Gulf and 10-100 m in the Oman Sea. A total of 316 stations were randomly selected and the biomass and CPUA were estimated by swept area method during this three years period, the strat A and B weren’t covered. The comparison between two regions indicated that the percentage of density of demersal fishes in the Persian Gulf during years 2012, 2013 and 2014 were 1.0, 1.4 and 1.6 times more than the Oman Sea and totally 50-60% of total biomass was found for the Persian Gulf. Also a comparison among 17 strata the highest biomass was found for K region (Sirik to Jask) in the Oman Sea in 2012 & 2014; and C region (Genaveh to Bordkhoon) in 2013 in the Persian Gulf. The same comparison was done for CPUA of commercial, non-commercial and total in both water bodies and it was found that in years 2012 to 2014 the region K (Sirik to Jask) in the Oman Sea and Stratum Q (Bersi to Gwatr) had the highest value of CPUA. On the contrary, the stratum M (Biahi to Galak estuary) showed the lowest value of biomass for both commercial and non-commercial fishes. With review the mean CPUA in different depth layers for years 2012, 2013 and 2014, it was concluded that in the Oman Sea with increasing the depth, the mean CPUA is decreased and the lowest CPUA belongs to depths of 30-50 m The comparison between commercial and non-commercial groups in both ecosystems, it concluded that the density of commercial species were higher than non-commercial ones; and for years 2009, 2010 and 2011 the commercial species consist of 63.4, 65.0 and 59.7 % of total biomass. In all years the Persian Gulf indicated higher values than the Oman Sea. The most abundant fishes were Rays, Ribbon fishes, Carangids, Grunts, Japanese threadfin bream, Lizardfish and Barracuda for both Persian Gulf and Oman Sea