نشریه بوم شناسی منابع آبی
سال پنجم شماره 1 (بهار و تابستان 1400)

In the plan of developing aquaculture and increasing production in the lake behind Vahdat Dam (Kurd Kennedy) in Bostan, East Azerbaijan, planktonic studies were considered as basic studies to increase fish production in this lake. In this project, 5 study stations were considered in the area of the dam lake and the river entrance.The studies started quarterly from the winter of 2010 and continued for one year until the fall of 2011. For zooplankton sampling, 30 liters of water was filtered by a 30-micron zooplankton hunting net. Finally, the samples were fixed with %4 formalin and identified in the laboratory after specimen preparation and microscopy. In zooplankton studies, 5 zooplankton branches and 24 genera were identified in this lake. In total, Rotifra branches with the genera of Keratella, Polyarthera and Syncheata with %50.9 of the zooplankton population of the lake are the most abundant and Ciliphora with % 41.4 of the zooplankton population of the lake are in the next rank. Comparison of planktonic observations and physical and chemical data of water, showed that Vahdat lake have talents and suitable Zooplankton species for feeding and rearing their fish.

Shrimp farming is a young and dynamic business with a history of rapid change in response to technological advances. The first advances in shrimp farming technology occurred in Japan in the late 1930s. Due to the unfavorable climate and species of Japan for commercial production, the technology was transferred to other countries in Asia and the United States in the 1970s. The increasing prevalence of the disease in wild populations led to the introduction of the pathogen-free Shrimp Litopenaeus vannamei (SPF) produced by the US Marine Shrimp Consortium to Asia and its replacement by fast-growing, native species. Transplantation without screening, without adequate testing and testing, led to the spread of WSSV in Asia from the Americas to the point where breeders often looked healthy but were present at low levels of the disease and remained undetected. Thus, as the disease progresses, terms such as specific pathogen-free generators (SPF), specific pathogen-resistant generators (SPR), pathogen-free generators (PF), specific pathogen-tolerant generators (SPT), high-health generators (HH) and other terms It was created for the production of reliable breeders and overseas transmissions, and now the OIE annually updates the list of these diseases and terms, and the manufacturing companies are obliged to comply with it.

One of the most important phenomena in marine waters is phytoplankton blooms or tides. A sudden increase in marine microalgae can be seen in coastal or offshore seas and oceans. These blooms can be related to toxic or non-toxic microalgae, which in general will lead to a decrease in water-soluble oxygen and thus the loss of aquatic life. In toxic blooms, there is a greater danger lurking for aquatic animals as well as humans because the released toxins attack the gills, liver and all aquatic organisms and thus have a direct and indirect impact on the economy, health and biosafety of beach dwellers. In recent years, many reports have been published about the occurrence and spread of various phytoplankton tides in the northern parts of the Oman Sea (Iran) and the south (Oman and other related areas), and the algae that cause the blooms have been identified and introduced. One of the most common and widespread was the bloom related to the microalgae of the genus Noctiluca scintillans. In this study, the history of phytoplankton blooms in the waters of the Oman Sea, the probable cause of their occurrence, phytoplankton populations with high prevalence and in particular the blooms related to the genus N. scintillans will be investigated.

The value and importance of fishery products in terms of nutrients such as poly unsaturated fatty acids omega-3 and high protein content are known for everyone, but these products are very perishable due to having these valuable nutrients, and their handling, processing and storage processes must be done with a certain speed, accuracy and delicacy to ensure quality and increase their durability, which requires the use of various cooling methods, especially ice, which is the fastest, cheapest and easiest way to maintain. The use of ice due to its cheapness, portability, reduction of fish storage temperature and washing of fish that occurs with the melting of ice eliminates pollution and maintains fish moisture. As a result, it maintains the quality of the fish and delays the processes of enzymatic, microbial and chemical spoilage. In this article, the application of ice in different stages of handling, processing and storage of aquatic animals is described.

Nanotechnology has become a global competitor. Countries that have lagged behind industrialized countries in some areas have once again had the opportunity to compete with developed countries in new areas. Due to the increasing growth of nanotechnology, researchers in various fields and fields have tried to use it. Based on the applications discussed in this article, it can be said that nanoparticles can increase fish production by creating better hygienic conditions in fish ponds; Also, using special nano-hooks, the amount of aquatic fishing can be increased. Once available to fish (either by farming or fishing), nanoparticles can ensure optimal product delivery to customers by providing the right packaging. In addition, as mentioned, by producing nanocapsules and introducing aquatic nutrient particles into daily foods, they can be added to people's food baskets. As the article shows, these were examples of nanoparticles being used in aquaculture, fishing and fish processing. . .

Gillnets are one of the most considerable passive fishing gears that are set vertically in the water, and the fish that swim towards them are caught. The process of catching through the net is mainly by stuck their operculum into the meshes. The principal mechanism of these nets is deception, based on making the fish indifferent to the danger (fishing gear). If these gears stay in one place for a certain period, they are called set gillnets and are the most remarkable tools in coastal (inshore) fishing. Anchored (set) gillnets are usually fixed in the seabed through massive metal anchors or set near the bottom and other water surfaces via a buoy and weight retention system. Due to the shallow water depth in the fishing grounds of Khuzestan Province, the use of anchored gillnets in the different deepness of setting the nets for catching various fish species, such as epipelagic (narrow-barred mackerel), benthopelagic (silver pomfret), demersal (fourfinger threadfin), and littoral (Liza) has long been customary. The most important results of replacing anchored gillnets with trawling for fishing will include improving the environmental situation, preserving commercial fish stocks, and the economic prosperity of the fishing community.

Aras reservoir was established on the Aras River in border line of Iran and Azarbaijan. This is one the largest reservoirs in the country and deserved for its contribution in fisheries, drinking and agricultural water supply and recreational application in the region and country. This paper attempts to review Aras reservoir pollutions and phytoplankton blooms occurring in this freshwater ecosystem. The most conspicuous pollution resources of this reservoir were human activities such as agriculture (irregular use of fertilizers and pesticides), urbanization (absence of waste water purification systems), climate change and global warming. High levels of nutrients particularly phosphorous and nitrogen entered into the reservoir create harmful algal bloom particularly in warm and dry season. Cyanobacteria produced by blooms not only, have negative effects on the taste and odor of water and species diversity, but also, produce poisons that lethally impact on human and aquatic organisms. The algal species that induce blooms in the Aras reservoir were Microcystis botrys and Pseudanabaena limnetica. This review indicates that continuous monitoring of Aras reservoir and river water using physical, chemical and biological indices should be regarded as priority of research centers and related organizations.