An effective method for reducing belly-bursting in frozen oil sardines

A dip treatment in 15% sodium chloride solution for 30 minutes prior to freezing was found to be effective in reducing belly-bursting occurring during freezing and thawing of oil sardines. The effect of size and fat content of sardines on belly-bursting phenomenon and storage characteristics of brine treated sardines have been studied.

Challenges to effective fishing and preferred fishing gear in a hydrodynamic freshwater system

Challenges to fishing and preferred gear of multiple used Lake, whose water depth is controlled by opening of its dam gate were investigated. Geographic survey, interview and focused group discussion of fishermen were used to assess factors influencing effectiveness of fishing and the preferred gear of Asejire Lake. Water usage (s) such as frequency of Complete and Partial Opening of Dams Gate (CODG and PODG) were investigated as indices for hydrodynamic condition. Response during focused group discussion with about 33% of fishermen of the Lake were obtained on sources of disturbance to effective fishing (SDEF), most effective gear (MEG)- least environmentally perturbed gear, comparability of catch structure of preferred gear to conventional gear and sustainability of superiority of preferred gears in situations outside hydrodynamic condition (SSPPG). The PODG occurred 1-7times/Month-dry season, 15-18times/Month-wet season; CODG occurred 1-2times/Month in both season; Interval of CODG was 3-17 and 5-12days (dry and wet season). It affected set-net and catch. The SDEF were gear availability, weather condition, dam’s gate opening, religion activities and Health of fisher-folks. 50% respondents accepted opening of dams gate as most important disturbance while religion was least (5% respondents accepted). 60% respondents accepted traps as MEG being the least affected while 75% respondents accepted Gura cage trap as the MEG among traps.90% respondents accepted that among traps, its catch structure was closest (comparable) to conventional gear. However, 75% respondents rejected SSPPG. Opening of dams’ gate creates hydrodynamic condition and it affects fishing. Gura trap was preferred for fishing hydrodynamic condition.

On the selection of effective impulse frequencies for specific movements of fish in an electrical field

In order to determine effective pulse limits for Salmo irideus, Cyprinus carpio, Gasterosteus aculeatus, Tinca tinca, Salmo fario and ldus melanotus in impulse D. C. for galvanotaxis and galvanonarcosis, studies were carried out with rectangular and square impulses. The narcotizing pulse limits remained constant for each variety in an impulse D. C. of specific wave form. The anodic effect of fishes was better in square wave form and varied with the variation of temperature of surrounding medium. S. fario reacted better when placed parallel to the lines of electrical force. Transversal escape movement occured when the axis of fish body was at right angles to the direction of current.

Studies on thermal deffusivity [i.e. diffusivity] and conductivity of fresh and dry fish

Thermal diffusivity (α) and conductivity (K) of fresh and dry cured fish at different moisture levels were investigated by a calorimeter (regular regime) method and transient line source technique. Thermal conductivity has a linear correlation with packing density and percentage water content. K values calculated from formula method and line source technique are comparable.

On the measurement of concentration of blanching brine by electrical conductivity method

Blanching is an important operation in the shrimp canning process, in order to bring down the moisture content of the product to the required level, to allow the proteins to coagulate and to give proper texture, shape and characteristic pink colour to the meat. It has been observed that among other factors responsible for fluctuations in the drained weight in the canned prawns, concentration of brine used for blanching and the duration of blanching are important (Varma, Chaudhury and Pillai 1961). The papers gives details of experiments

Status of hilsa (Tenualosa ilisha) management in the Bay of Bengal: an assessment of population risk and data gaps for more effective regional management

Assessment of country status papers on hilsa fisheries presented at the BOBP – IGO Chittagong, Bangladesh 2010. Assessment of status hilsa management in Bangladesh, India and Myanmar. Brief recommendations of potential follow-up activities that could enhance management. Risk assessment of hilsa in each country with Productivity Susceptibility Analysis (PSA). Summary of new approach to assess ecological risk.

Survey of plankton blooms and red tides and their interaction with environmental factors through monitoring satellite images

One of the most important marine ecological phenomena is red tide which is created by increasing of phytoplankton population, influenced by different factors such as climate condition changes, utrification hydrological factors and can leave sever and undesired ecological and economical effects behind itself in the case of durability. Coast line of Hormozgan is about 900km from east to west, within the range of geographical coordinates of 56 16 23.8, 26 58 8.8 to 54 34 5.33 and 26 34 32 eastern longitude and northern latitude, seven sampling stations were considered and sampled for a period of one year from October 2008 to October 2009. after the analysis of Satellite images, monthly, during the best time. In several stages, samplings were performed. In each station, three samples were collected for identification and determination of Bloom- creating species abundance. Cochlodinium polykrikoides was the species responsible for the discoloration which occurred at October 2008 in Hormozgan marine water. Environmental parameters such as sea surface temperature, pH, salinity, Dissolved Oxygen concentration, Total Dissolved Solids (T.D.S.), conductivity, nitrate, nitrite and phosphate and also chlorophyll a were measured and calculated. Kruscal Wallis test was used to compare the densities between different months, seasons and the studied stations. Mann-whitney test from Nonparametric Tests was used for couple comparison. Pearson correlation coefficient was used to determine the relationship between physical and chemical data set and the abundance of Cochlodinium polykrikoides. Multivariate Regression and analysis of variance (ANOVA) also were used to obtain the models and equations of red tide occurrence relationship, environmental parameters and nutrient data. The highest density was 26 million cells per liter in Qeshm station. A meaningful difference was observed between sampling months and seasons but there was no between sampling stations which indicates that in favorable conditions, the occurrence of this phenomenon by the studied species is probable. Regarding to β coefficients of nitrate, temperature, phosphate, Total Dissolvable Solutions (T.D.S) and pH these parameters are effective on the abundance of this species and red tide occurrence. Increase in these factors can represent the effects and outcomes of human activities and increase in marine pollution.

Recognizing of Ichthyophon and investigation of feeding and effects of water temperature, salinity and electrical conductivity on the population dynamic of Barbus grypus in the Dalaki and Helle river

This study was carried out for recognized ichthyophon and investigation of feeding and effects of water temperature, salinity and electrical conductivity on the population dynamic of Barbus grypus in the Dalaki and Helle river. In the study period, 2949 Barbus grypus was cached. The most of total length frequency was 200 to 300 mm and 2 to 3 years old. The oldest fish was8 years old with 756 mm total length. Fecundity was 950 upto 57400 oocyt per fish. Station no. 6 and 7 showed more temperature, fecundity and GSI than other stations. Females adulated before then males. Multiple stepwise regression of fecundity and RE (reproduction effort) showed significant correlation. Fishes of the upper parts of stream was more L than down stream stations. Condition factor of males was more than female, and for down stream stations was better than the other stations. Barbus grypus is omnivorous. Ichthyophon of Dalaki river include 4 family and 9 species that Capoeta capoeta intermadia was more than others species, but in the Helle river was 5 family and 9 species, that Liza abu zarudni was more than others.