We analyzed the Dissolved Oxygen (DO) level in the surface water off Namkhana, a sampling station in the lower Gangetic delta region. Our three decade analysis in three different reasons (premonsoon, monsoon and postmonsoon) exhibits a decrease in the DO value with the passage of time. Based on the DO value we carried out a premilinary Water Quality Index (WQI) analysis using the average seasonal temperature of the study region. This index can be used as proxy to aquatic health in the study site, provided other relevant variables remain within the optimum range. The DO level varies as per the sequence monsoon > postmonsoon > premonsoon. The sudden rise of DO level and WQI during premonsoon 2009 is attributed to Aila, a super cyclone that passed across the lower Gangetic delta on 25th May, 2009 with a speed of ~110 km/hr.

Background and Aim: lysozyme has been known as a significant component of the innate immune system of fish. It is reported that the g-type and c-type lysozymes have been identified in fish. Oplegnathus fasciatus is one of the economically important cultured species, generating higher market value and demands in Korea. Contrary to the heavy consumption of O. fasciatus, however, there has been very limited information on their immune system and immunity genes responding against diseases.

Background: Biopolymers have many fields of application. In Echiniculture they are usually employed to bind trial diets, although a systematic study on the performances of biopolymers as feed binders is lacking. Methods: Several biopolymers (sodium alginate, agar, gellan, apple pectin and citrus pectin with different esterification degree) were employed as binders in the manufacture of biocomposites to be used as Paracentrotus lividus feed. Biocomposites were first produced with varying percentages of feed ingredients (5-25%) and polymers (2-3%), either alone or in blends of two types. Biocomposites were tested for stability, swelling and nutrient release in water. In order to evaluate their palatability, biocomposites were administered to sea urchins and eating activity checked up to 48 h. GI and gonad composition were evaluated in a 14-week rearing trial.

Background and Aim: The intensive nature of aquaculture has subjected fish to a number of stressors in the culture medium, anesthetics are widely used to minimize the issue of stress during farming operations and activities. Clove oil is a well known, established and acceptable anesthetics commonly used in aquaculture, this anesthetics is not readily available in developing countries, thus leaving the fish farmers with option of using the locally available plant extracts as anesthetic agent in fish culture. This study therefore assessed the efficacy of aqueous extracts of clove seed and its effect on hematological parameters of the fish.

Solar tent fish drier (STFD) reduce post-harvest losses, thereby ensuring continuous availability of cheap animal protein. This study aimed to: (1) minimize post harvest losses by improving the shelf life dried fish; (2) enhance technology multiplication and dissemination system; (3) create clear insight about the technology implementation. This study was carried out in the northern and northwestern part of Lake Tana from June, 2014 to June, 2015. Purposive sampling methods were used to select Dembiya, Alefa and Gondar zuriya districts with their respective locality. Transact walk, interview, focus group discussion, and stakeholder consultation were used to collect qualitative data. Quantitative data were collected from 38 sample households by preparing structured questionnaire. Likert scale scoring, descriptive statistics such as percentage, mean, and standard deviations were used for analysis. The age structure of the sample households shows an average of 33.97 years and 44.7% of the respondents were female. Sample households average family size is 4.6 and the distance from the home to the main road takes 63.89 minutes of walk. The solar tent fish drier was prepared from readily available materials such as; wood, white and black plastic, nail, rope and mesh wire with a size of 2meter height and 1.7 meter length. For this activity, six tents were prepared for three districts and fish species selected for the activity was labeobarbus intermedius. The salt amount used was 60gram iodine salt per liter in brine form. The weight of dried fish becomes stable and dried well in the third day; with total moisture losses of 60%. Drying fish by solar tent fish dryer enables to produce hygienic, high quality, organoleptically good dried fish with low cost. By drying quickly it is possible to reduce post harvest losses thereby ensuring continuous availability of cheap animal protein. Absence of better price for fish dried by solar tent is the main challenge for further adoption. Promotion and market linkage for the quality dried fish; continuous support and follow up are very important to sustain the technology.