Belonging to Scombridae family, longtail Tuna (Thunnus tonggol) is an economically important epipelagic species inhabiting tropical to subtropical regions of the Indo-Pacific, and is found almost exclusively in the neritic waters close to landmasses and rarely in offshore, turbid waters and estuaries (Froese and Pauly, 2015). Longtail Tuna catch by gillnet fleets is done in the coastal waters of different countries including Iran, Indonesia, Pakistan, Malaysia, Oman, Yemen, India and Thailand (Pierre et al., 2014; Geehan et al., 2016). This species is one of the smallest species of the genus Thunnus, but relatively large compared...

The present study is an attempt to analyze the value chain of Tuna and Tuna-like species. The study is intended to show the main loops of Tuna and Tuna-like species industry along with their relations. Also, the present study indicates the current map of value chain along with its problem tree for Tuna and Tuna-like species in Iran. According to test hypothesis, the status of Tuna and Tuna-like species value chain is not ideal in Iran. Weak market for various Tuna products (lack of variety in the production of canned goods and the non-canned products), low rate of export to Iraq, Afghanistan and Central Asia (high cost, lack of competitiveness and non-flexibility of the rules and regulations for producing products with the preference of exporting countries) and the weakness in the export of the fresh Tuna to Japan and the European Union for added value products (non-compliance with the target countries criteria and the weakness of the transport infrastructure, especially in the air transit) were identified as the main problems. Also, in the present study, the missing and weak factors which reduced the efficiency of the value chain were identified in forms of the problem trees and ranked by Friedman test. The results of this study showed that the value chain of Tuna and Tunalike species suffer from the lack of fair distribution of profit between the value chain loops, no diversification in the production of value added products, neglecting the quality in the value chain and poor access to the export market of value added products.

In this research work the production of sweet product from Thunnus albacares known as yellow fin Tuna and its shelf life was studied. From fillet f Tuna two sweet sampled in laboratory were prepared. One of them was from raw and second one from cooked fillet. As the results of the orgenoleptic test showed the first sampled was rejected and second one was acceptable. The moisture, protein, fat, ash content and organoleptic score for these samples were 15.26%, 66.7%, 8.5%, 10% and 7 respectively. According to a time table, the shelflife of this product was determined by monitoring the changes of TVB-N, PV, total bacterial count and organoleptic properties of the samples which kept at 3-4oC in a laboratory frige for 30 days. The results showed that, the sample had a natural had a natural flavor, smell, color and texture for 15 days. The number of bacteria increased from 4.7×103 to 9×103 colonies per gram, TVB-N and PV also increased from 48.3 to 60.3 mg/100g and 0.2 to 3.4 meq/kg. Then peroxide value started to decreased, According to these results, the sheflife for this product recommended to be 15 days at 3-4oC.

Examining comparative and compettitive advantage is one of the most important criteria to make production and export decisions. For this reason and based on the opportunity cost concept, a vaiety of methods and indices is proposed. This article is to investigate the Iran's comparative advantage applying Policy Analysis Matrix, Internal Factor Cost, Export Competitiveness and Government protection Coefficient as well as Government aids and indirect taxes in 2019. Hence, following the factor's Cost extraction and PAM Matrix at the first stage, different competitiveness and comparative advantage indices were computed. Based on the results of Internal Factor Cost and Unit Cost Advantage Indices, one can say Iran has competitive advantage in domestic fishery markets withput any depency to government subsidies. Moreover, considering the subsidies payd for factors and the excercise taxes imposed on the final fishery outputs, government gain a net value added tax at whole. Finally, counting UCd and UCx indexes show that fishery industry have had a competitive advantage in 2019.

Yellowfin Tuna (Thunnus albacares) is one of the most important commercial and neritic fish species which has known because of ecological importance and wide distribution around the world. The aim of this study was to determine relative index of abundance for Yellowfin Tuna from 2007 to 2016, also we evaluated effect of some explanatory variables (year, month, vessel tonnage and net height) of catch per unit effort data in traditional gillnet fishery standardized by general linear model (GLM) in the Oman Sea. Standardized catch per unit effort is an important entrance in stock assessment as an annual abundance index. The results of this study have shown that all explanatory variables influence CPUE significantly in GLM model with lognormal error distribution; CPUE of Yellowfin Tuna increased 0. 007 and0. 0016 by raising one ton of vessel' tonnage and one meter of net height, respectively. Relative index of abundance of Yellowfin Tuna has the lowest quantity in 2011, remain stable till 2013 then increase to highest level in 2016, which is shown the catch rate can increase by raising catch effort. There is a seasonal trend in standard CPUE of Yellowfin Tuna with the highest catch rate in cold season. Monthly relative index of abundance has shown highest catch rate occurred in February and March.

Gelatin as a portentous component is important in the food, pharmaceutical, medical abd technical industries. Gelatin is used in food industrials to prepare marmallads, jellies, confectioneries and ice cream. The main purpose of this research was to optimize the usage of cheap primary material, i.e. a lot of fishery wastes for extraction of gelatin and to decrease the importation gelatin from abroad that is usually prepared from pig skin and wastes of animal. This research was conducted in two stages. In the first stage, the effect of pH conditions ( in alkaline and acidic conditions) and type of raw material (three raw material: fillet plant wastes, fish shark fish hoof) were evaluated on some best qualitative and quantitative Characteristics of gelatin( yield, purification value, color and odor and flavor). In second stage, the temperature effect ( in 3 levels,70,75,80 degree of centigrade) and pH in 2 levels (6.5 and 6) were evaluated on the gelatin yield content. It should be mentioned that all of raw material were prepared from fishery factory of Booshehr.The results from first stage showed that using from alkaline condition and fishery wastes, the amount of gelatin will be maximum with pH=6.5, temperature=70 degree of centigrade. Also under the same conditions the best quality gelatin can be obtained.

In this paper, the large amount of sedimentation and the resultant shoreline advancements at the breakwaters of Beris fishery Port are studied. A series of numerical modeling of waves, sediment transport, and shoreline changes were conducted to predict the complicated equilibrium shoreline. The outputs show that the nearshore directions of wave components are not perpendicular to the coast which reveals the existence of longshore currents and consequently sediment transport along the bay. Considering the dynamic equilibrium condition of the bay, the effect of the existing sediment resources in the studied area is also investigated. The study also shows that in spite of the change of the diffraction point of Beris Bay after the construction of the fishery port, the bay is approaching its dynamic equilibrium condition, and the shoreline advancement behind secondary breakwater will stop before blocking the entrance of the port. The probable solutions to overcome the sedimentation problem at the main breakwater are also discussed.

To achieve comprehensive management of marine resource stocks requires knowledge of the variables that affect economic species. Longtail Tuna (Thunnus tonggol) is one of the most economic species in the southern waters of Iran. Recent study tried to find out the association between the most important satellites derived environmental variables with longtail Tuna catch and distribution by applying Generalized Additive Model (GAM) in the southern waters of Iran. Results indicated the relatively high importance of temporal (month of fishing), spatial (latitude), and three environmental variables as Sea surface salinity (SSS), mixed layer depth (MLD), and Sea surface temperature (SST). Deviance explanation of the GAM model defined as 62. 3% and adjusted R-square was 0. 595. Maximum Entropy (MaxEnt) habitat suitability modeling by selected tree environmental variables shows longtail Tuna inhabited mostly in latitude between 24° N and 26° N close to Hormozgan and Sistan and Balochistan province waters. The current study by detecting most important satellite derived environmental variables and high suitable habitat, could assist decision makers and fishery managers to improve fishing efficiency of Iranian purse seiners and helps implementation of ecosystembased fisheries management of shared stocks in southern waters of Iranian.