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The aim of this study was to determine the relationship between spinner hook sizes (2, 3 and 4) and hook selectivity for Oncorhynchus mykiss (rainbow trout), a species important to recreational fisheries in Karakaya Dam Lake in Eastern Turkey. A total of 24 sampling trips were carried out twice per month by the same three anglers from May 2013 to April 2014. The SELECT method was used to determine the selectivity parameters. An analysis to determine the differences in the catch per unit effort (CPUE), yield per unit effort (YPUE) and condition factor values based on different hook sizes was conducted using one-way ANOVA. During the spinner hook-size experiments, we captured 202 Oncorhynchus mykiss, which ranged from 14.5 cm to 46.0 cm TL in length and weight 30.2 g to 1320.2 g. The mean lengths (±SE) of Oncorhynchus mykiss captured on the three spinner hook sizes were determined. The optimum lengths calculated by log-normal model were found to be 18.28, 27.41 and 36.55 cm for No 2, No 3 and No 4 hook sizes, respectively. © Published by Central Fisheries Research Institute (CFRI) Trabzon, Turkey. Source

Sener E.,Suleyman Demirel University of Turkey | Terzi O.,Suleyman Demirel University of Turkey | Sener S.,Suleyman Demirel University of Turkey | Kucukkara R.,Egirdir Fisheries Research Institute

This study presents a model to estimate lake water temperatures using Geographical Information Systems (GIS) and Artificial Neural Network (ANN) techniques. Lake Eǧirdir was selected as the case study area because it is one of the important surface water resources in Turkey. Initially, the water temperature of the lake was determined using 44 stations by in-situ measurements. The relative humidity, air temperature, air pressure, and water depth parameters were used to develop the ANN models for estimating the water temperature of Lake Eǧirdir. The parameter maps were derived by using GIS techniques. The developed ANN models were very effective in the estimating of water temperature for Lake Eǧirdir. The best ANN model having an R2 of 0.949 and MSE of 0.075°C2 is based on the input parameters of, relative humidity, air pressure, and water depth. The results of the best ANN model were compared with the in-situ measurements and shows that the modeling results are compatible with the in-situ measurements of the lake water temperatures. Finally, the ANN method found was useful for estimating lake water temperature in which water temperature measurements are quite difficult, especially for large lakes, or to estimate missing water temperature data. Source

Apaydin Yagci M.,Egirdir Fisheries Research Institute | Ustaoglu M.R.,Ege University
Turkish Journal of Zoology

In the present study the zooplankton fauna of Lake İznik (Bursa) was investigated during January-December 2006. A total of 54 taxa-35 taxa from rotifers, 14 taxa from cladocerans, and 5 taxa from copepods-were identified in Lake İznik. Brachionus calyciflorus, B. angularis, Notholca squamula, N. acuminata, Euchlanis dilatata, E. deflexa, Platyias quadricornis, Trichocerca similis, T. cylindrica, T. chattoni, T. lophoessa, T. bicristata, Asplanchna girodi, Conochiulus dossuarius, Synchaeta pectinata, Lecane luna, L. bulla, L. stenroosi, L. clostrocerca, L. lunaris, Lepadella patella, Dicranophorus forcipatus, Mytilina mucronata, Lophocharis salpina, Trichotria tetractis, T. pocillum, Testudinella patina, Hexarthra fennica, and Collotheca sp. from the rotifera species; Diaphanosoma lacustris, D. orghidani, Daphnia cucullata, Ceriodaphnia quadrangula, Macrothrix laticornis, Alona rectangula, Leydigia leydigi, Graptoleberis testudinaria, Cyhdorus sphaericus, Pleuroxus aduncus, P. trigonellus, Alonella excisa, and Phrixura rostrata from the cladocera species; and Eucyclops macruroides, Paracyclops fimbriatus, Cyclops vicinus, and Thermocyclops crassus from the copepoda species are new records for Lake İznik. According to the Q Brachionus/Trichocerca index (Q = 0.8) used for the determination of trophic level, the lake is oligotrophic. © TÜBİTAK. Source

Yerli S.V.,Hacettepe University | Emiroglu O.,Eskiehir Osmangazi University | Yegen V.,Egirdir Fisheries Research Institute | Uysal R.,Egirdir Fisheries Research Institute | And 4 more authors.
Turkish Journal of Fisheries and Aquatic Sciences

Introduction of a new species to a new habitat may lead to a catastrophy. Prussian carp Carassius gibelio (Bloch,1782), by its high reproduction capacity by means of gynogenesis and tolerance to environmental changes, considered as asuccessfull invasive. It can become the dominant species in new habitat in a short time with the help of these attributes. After the first spread report ofCarassius gibelio from Thrace in 80’s, Carassius gibeliobecame to be a problem in inland waters of Turkey as it is in some countries of Europe. This study is a review of distribution of Carassius gibelioin Turkey. 39 stream, 33 lake, 67 reservoir and 55 pond records were presented in this study. And according to these results, only four basins (Ceyhan, öksu,Western Black Sea, Eastern Black Sea and öksu) out of 26, seems to show no distribution of Carassius gibelio. ©Published by Central Fisheries Research Institute (CFRI) Trabzon, Turkey. Source

Cetinkaya S.,Egirdir Fisheries Research Institute | Uysal R.,Egirdir Fisheries Research Institute | Yegen V.,Egirdir Fisheries Research Institute | Cesur M.,Egirdir Fisheries Research Institute | Bostan H.,Egirdir Fisheries Research Institute
Turkish Journal of Fisheries and Aquatic Sciences

In this study, growth properties of sand smelt (Atherina boyeri, Risso 1810) in İznik Lake were determined. Total catched 237 sand smelt fish in January-December 2006 were 28.3% male and 71.7% female. Female male ratio was 2.5:1. Fork length between 2-10.6 cm, weight 0.06-10.5 g, ages I-IV were changed and 20.7% fish were I. age were determined. Differentiation between average lenght frequency of groups wasn't statistically significant (P>0.05) in I. age group. The data were obtained LogW=-2.09593-2.9819 Log L and W=0.008018 L 2.9819(r=0.993) for male fish, Log W=-2.12773-3.0508 Log L and W=0.007452 L 3.0508(r=0.996) for female fish and Log W=-2.13401-3.0511 Log L and W=0.007345 L 3.0511(r=0.994) for male and female fish. Total, natural and fishery mortality rates respectively were M=0.666 y -1, F= 0.1591 y -1and E=0.193 y -1. The highest relative length and weight growth were shown male and female between I-II ages. For female and male fish W ∞=32.3, K=0.23794, t o= -0.1994, b= 3.0511 and Von Bertalanffy weight growth equation W (t)=32.3 *(1-e -0.23794(t+0.1994)) 3.0511were determined. Condition factor were determined K=0.780 for male and K=0.822 for female and differentiation between sexual groups for II to III statistically were not significant (P>0.05). © Published by Central Fisheries Research Institute (CFRI) Trabzon, Turkey in cooperation with Japan International Cooperation Agency (JICA), Japan. Source

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