Turkish Journal of Fisheries and Aquatic Sciences 

About: Turkish Journal of Fisheries and Aquatic Sciences is an academic journal published by Central Fisheries Research Institute of Türkiye. The journal publishes majorly in the area(s): Population & Biology. It has an ISSN identifier of 1303-2712. It is also open access. Over the lifetime, 1549 publications have been published receiving 17960 citations.

Growth, Survival and Gut Microbial Load of Rainbow Trout (Onchorhynchus mykiss) Fry Given Diet Supplemented with Probiotic During the Two Months of First Feeding

Abstract: A commercial Bacillus spp. probiotic was tested on rainbow trout fry during the two months of first feeding. Probiotic was introduced in diets at five different levels, (T1: 4.8×10 8 , T2: 1.2×10 9 , T3: 2.01×10 9 , T4: 3.8×10 9 , T5: 6.1×10 9 CFU g -1 ) and their effects compared with those of control diet containing no probiotic. Survival in treatments was significantly (P<0.05) higher than control and a slight increasing mortality rate was observed during the first week of experiment. The counts of bacteria associated with trout intestine in all treatments were significantly (P<0.05) higher than controls and Bacillus spp. was not detected in controls. Total bacteria counts were significantly different among treatments and controls; it may suggest that the colonization rate of digestive tracts of rainbow trout fry with bacteria was affected by dietary bacteria level. Specific growth rate, condition factor, protein efficiency ratio were slightly but significantly (P<0.05) higher and feed conversion ratio was lower in groups received probiotic via diets than controls. It may show that probiotic stimulates digestive development and enzymatic activity in fish. Growth performance in treatment received 3.8×10 9 CFU g -1 showed the best results. Therefore, it does not appear that higher levels of probiotics improved results and suitable doze of probiotic should be assessed before application in large scale to prevent any undesired effects. The supplementation of trout starter diet with Bacillus spp. is probably effective for improving rearing conditions.

The Use of Electronic Tags in Fish Research – An Overview of Fish Telemetry Methods

Abstract: An overview of electronic tags that can be used in fish research is given, including radio and acoustic transmitters, data storage tags (DST, also termed archival tags), pop-up satellite archival tags (PSAT) and passive integrated transponder tags (PIT-tag). Fish telemetry is a term used to describe the application of these methods. Typically, an electronic tag is attached to a free-swimming fish, and information on position, movements and/or measurements of environmental and physiological parameters can be recorded wirelessly by use of a mobile receiver or stationary loggers. For most methods, the fish need not to be recaptured to achieve data. However, DSTs record and store information on environmental and/or physiological parameters in the tag, and therefore need to be retrieved for downloading data. In the case of PSATs, stored data is transferred to satellites when the tag loosens from the fish and pops up to the surface, and in addition, the pop up position is recorded. The developments of telemetry methods have provided opportunities to reveal previously unknown information on fish behavior, habitat use and migrations in fresh water, estuaries, near-coastal areas and oceans, especially since extensive longterm data can be collected repeatedly from individual fish. Detailed information on fish behaviour and migrations is needed to better understand, protect and manage fishes in freshwater and marine systems. The development of successful management measures depends on knowledge of where fish reside and migrate during the day, season and year. There has been a tremendous increase in the use of electronic tagging methods, especially during the last 10-20 years. In addition to descriptive and ecological studies, the methods have been used to assess effects of for instance hydropower production, other river regulations, migration barriers, protected areas, fishing regulations, catch-and-release angling, hatchery-rearing, fish aggregating devices (FADs), water pollution and aquaculture. The main methods for attaching electronic tags to fish are 1) surgical implantation in the body cavity, 2) external attachment, and 3) gastric insertion via the mouth. Potential negative handling effects are inflammations, infections, tag expulsion, altered behavior, decreased swimming performance, reduced feeding, reduced growth and increased mortality. The catch, handling and tagging procedures should have minimal effects on the fish. If not, an anomalous behaviour caused by the tagging may be recorded instead of the natural behaviour, and the study is a failure from a scientific point of view. Furthermore, optimal anaesthetic and tagging methods are required to meet the ethical standards for use of experimental animals, and to ensure fish survival and welfare.

Pollutants of Textile Industry Wastewater and Assessment of its Discharge Limits by Water Quality Standards

Abstract: Textile industry is one of the most important and rapidly developing industrial sectors in Turkiye. It has a high importance in terms of its environmental impact, since it consumes considerably high amounts of processed water and produces highly polluted discharge water in large amounts. Textile mills in Turkiye are required to control their discharge and therefore have started installing treatment plants in the name of environmental protection. The wastewater treatment plants of 11 textile mills in the woven fabric and knit fabric finishing industry were investigated in this study. Performances of the treatment plants were evaluated by in situ inspections and analyses of influent and effluent samples. The cost of the existing treatment plants is also evaluated. For the treatment of textile industry wastewater, biological treatment, chemical treatment and combinations of these are used. Plants utilizing biological treatment rather than chemical processes claim that their preference is due to less excess sludge production, lower operational costs and better COD removal in biological treatment. Waste water parameters in the effluent of biological treatment plants were in compliance with the ISKI (Istanbul Water and Sewerage Administration) discharge standards. However, if sodium sulfate in dyeing process and sulfuric acid in neutralization processes are used before a biological treatment, sulfate in the effluent exceeds 1700 mg/L. This problem can be avoided by using HCl or CO2 rather than H2SO4 in neutralization and NaCl instead of Na2SO4, if the use of Na2SO4 is not necessary.

Condition Factor of Four Cichlid Species of a Man-made Lake in Imo State, Southeastern Nigeria

Abstract: The condition factors of four cichlid species, namely Chromidotilapia guntheri, Tilapia cabrae, T. mariae and T. zilli from a man-made lake were studied over a period of 12 months (April 1997 to March 1998). Mean condition factor for C. guntheri was 4.58±1.53, while it was 5.27±0.56, 5.38±0.56 and 4.3±0.19 for T. cabrae, T. mariae and T. zilli,, respectively. There was a significant difference (t=1.85, p=0.05) in the mean condition factor of male and female C. guntheri, while in T. cabrae, T. mariae and T. zilli, there was not a significant difference in the condition factors of males and females. It was observed that the dry season condition factors of C. guntheri and T. mariae were higher than the wet season values, while in T. zilli, the reverse was the case with higher condition values recorded in the wet season. And there was not a significant difference between the condition factors of dry and wet seasons in T. cabrae. The general trend in the condition factors for length classes of C. guntheri, T. cabrae and T. mariae, is that relatively lower condition factors were recorded for relatively higher lengths of fish while relatively higher condition factors were recorded for relatively lower lengths of fish.

Assessment of the Water Quality of Oyun Reservoir, Offa, Nigeria, Using Selected Physico-Chemical Parameters

Abstract: The variations in selected physico-chemical factors were investigated for two years to determine the water quality of Oyun Reservoir, Offa, Kwara State, Nigeria for drinking and fish production. Three stations were chosen on the reservoir to reflect the effect of human activities, lacustrine and lotic habitats. Temperature, transparency, pH, conductivity, total dissolved solids, dissolved oxygen, nitrate, phosphate, chemical oxygen demand, total alkalinity, total hardness, calcium, magnesium, silica, sulphate, carbon dioxide were analyzed monthly between January 2002 and December 2003 using standard methods and procedures. The ranges of these factors were found to be comparable to those reported for other African reservoirs except for nitrogen and phosphate which were found in higher concentration above freshwater limits. Runoff of nitro-phosphate and sulphate fertilizers from nearby farm lands and washing of cows dungs from the watershed into the reservoir were found to have caused cultural eutrophication in the reservoir. The eutrophication was pronounced at Station 1 due to impact of human activities on the watershed, and with time, it will affect the water quality and fish production in the reservoir. The study concludes that Oyun reservoir has excellent water quality, high ecological status and passes chemical status. Eutrophication which was noticed to be a threat to the water quality should be arrested at the nick of time through denitrification and nutrient control to halt the degradation of the water.