Showing papers in "Turkish Journal of Fisheries and Aquatic Sciences in 2007"

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.

Weight-Length Relationships for 39 Fish Species from the North-Eastern Mediterranean Coast of Turkey

Abstract: Weight-Length relationships (WLRs) were estimated for 39 fish species from the north-eastern Mediterranean coast of Turkey. Samples were collected using trawl and longline gears at depths ranging from 5 to 100 meters. Captures were made between the years 2001 and 2003. The best-represented family was Sparidae with seven species, distantly followed by Serranidae (five species), Bothidae, Centracanthidae, Mullidae, Ophichthidae and Triglidae (two species). The remaining 17 families were represented only by one species. The estimates for the parameter b of the WLR (W = aL b ) ranged between 2.334 and 3.564 with a median of 2.987.

Haematological Profile of Clarias gariepinus (Burchell, 1822) Exposed to Lead

Abstract: Changes in Clarias gariepinus' blood cells were investigated after 96-h of exposure to lead. Ninety (90) Clarias gariepinus with average weight of 262.2g and average length of 30.8 were divided into 5 groups (A-E) at six (6) fish per group and in triplicates after being acclimatized for 14 days. They were then exposed to various concentrations (0, 25, 50, 100 and 200 mg/l) of lead nitrate. The packed cell volume (PCV) of the treatments decreased significantly relative to that of the control, while their platelet counts increased compared with the control. There was also a reduction in the RBC of treatments. Other blood parameters did not vary significantly in comparison to the control group, but it is worth noting that the mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH) and mean corpuscular haemoglobin concentration (MCHC) increased considerably in all treatments compared to the control. These alterations have been attributed to direct or feedback responses of structural damage to RBC membranes resulting in haemolysis and impairment in haemoglobin synthesis, stress related release of RBCs from the spleen and hypoxia, which was induced by exposure to lead. This study therefore gives an insight into toxic effect of lead on fish.

Length-Weight Relationship of 10 Fish Species Caught by Bottom Trawl and Midwater Trawl from the Middle Black Sea, Turkey

Abstract: Length-weight relationships are described for ten important demersal and pelagic fish species caught with bottom trawl: Merlangius merlangus, Mullus barbatus, Gobius niger, Alosa pontica, Spicara smaris, Scorpaena porcus, and midwater trawl: Engraulis encrasicolus, Sprattus sprattus, Trachurus trachurus, Pomatomus saltatrix from the Middle Black Sea. The samples sizes, minimum and maximum lengths and weights, length-weights relationships, ±95% CI of b, r2, growth type, and statistical analysis of the relationship between the sexes are summarized.

The Plankton and Fishes of a Tropical Creek in South-Western Nigeria

Abstract: Investigations on the physico-chemical characteristics, phytoplankton, zooplankton, finfish and shell fish component of an estuarine creek in South-western Nigeria was carried out for one year between March, 2003 and February, 2004. The study showed notable seasonal variation in the components investigated. Salinity regime seemed a major determinant of the composition, abundance and seasonal variation of encountered creek biota. Rain events associated with reducing salinities and tidal lagoonal inflow associated with increasing salinities may be key hydro-meteorological forcing operating in the creek. During the study, 82 species of phytoplankton, 18 species of zooplankton, 17 species for finfish, 4 species of shell fish and 7 categories of juvenile forms were recorded. In all, freshwater, estuarine and marine species of all trophic levels investigated were recorded in the creek at one time or the other during the survey. The array of juvenile forms recorded probably points to the suitability of the creeks characteristics to serve as breeding ground and place of refuge for diverse aquatic species.

Seasonal Variation of Total Lipid and Total Fatty Acid in Muscle and Liver of Rainbow Trout (Oncorhynchus mykiss W., 1792) Reared in Derbent Dam Lake

Abstract: Seasonal and monthly variations in the amount of total lipid and fatty acid in muscle and liver of rainbow trout (Oncorhynchus mykiss) reared in Derbent Dam Lake were investigated. It was determined that the amount of total lipids and fatty acids both in muscle and liver, varied by months and seasons (P<0.05). The amount of total lipid in muscle and liver reached its maximum in Autumn. The amounts of total fatty acid both in muscle and liver were determined to be higher in summer, Autumn and Winter seasons than that of Spring. Furthermore, the amount of total lipid and fatty acid was higher in liver than in muscle.

Effects of Stocking Density on Growth Performance, Survival and Food Conversion Ratio of Turbot (Psetta maxima) in the Net Cages on the Southeastern Coast of the Black Sea

Abstract: Black sea turbot (Psetta maxima) were reared at four different densities in the sea cages to evaluate the effects of stocking density on growth, survival rate and food conversion ratio. Fish (mean weight, 41 g; N: 900) were stocked in four different densities as 30, 60, 90 and 120 fish m-2 with three replicates and initial stock densities of 1.26±0.069, 2.44±0.022, 3.69±0.016 and 4.87±0.081 kg m-2 respectively. The growth trial lasted for 206 days from October 2000 to June 2001. Bulk and individual weights of fish in each cage were recorded monthly. The final mean weights (±s.e.) of the fish stocked at densities of 30, 60, 90 and 120 fish m-2 reached 178.3±6.53, 182.7±6.02, 186.1±8.22 and 164.6±8.12 g. Growth rate was fast up to 90 fish m-2and dropped after these. The corresponding SGR values were 0.70, 0.72, 0.73 and 0.68 % day-1 at temperatures ranging between 8 and 22°C and salinity of 17-18 ppm. The feed conversion ratios were estimated as 1.95, 1.85, 2.09 and 1.88, and cumulative survival rates were calculated as 78.0, 90.0, 75.0 and 65.3% respectively. The results revealed that stocking density had a significant effect on growth and survival rates of turbot. Fish held at the highest density exhibited lowest growth rate and survival rates.

The Phytoplankton Composition, Abundance and Temporal Variation of a Polluted Estuarine Creek in Lagos, Nigeria

Abstract: The phytoplankton composition, abundance and temporal variation of a polluted estuarine creek in Lagos was investigated for 6 months (February - July, 2003). Strong positive correlation (≥7.3) recorded between physico-chemical characteristics at two stations within the creek likely point to their control by similar factors, chiefly hydro-meteorological forcings and the creeks pollution status. A total of 48 taxa from 26 genera and 3 classes namely bacillariophyceae (37 taxa), cyanophyceae (10 taxa), and shizomycetes (1 taxon) were recorded for the study. Higher phytoplankton diversity recorded during the rains was probably due to the additional recruitment from the phytobenthic community as a result of scouring of the creek by floodwaters. The bacterium - Beggiatoa alba was the most abundant and frequent taxon particularly in the wet months and strongly indicates high levels of bio-degradable waste contamination. The physico-chemical characteristics and phytoplankton indicator species reflect a polluted and rapidly deteriorating estuarine environment.

Physiological and Histopathological Alterations Induced by Phenol Exposure in Oreochromis aureus Juveniles

Abstract: In the present study, the impacts of phenol as an environmental pollutant of the inland water habitat was studied on Oreochromis aureus (O. aureus juveniles. The fish of both sexes were subjected to three sub-lethal concentrations of phenol (20%, 40% and 80% of LC50) for seven days. The hepatosomatic index (HSI) was markedly increased, whereas the gonadosomatic index (GSI) was significantly reduced in the fish subjected to phenol. Some enzymes activities and metabolites were assessed in the liver, gills and muscle. The assayed enzymes are alanine and aspartate amino transferases (ALAT and ASAT) and lactate dehydrogenase (LDH). The measured metabolites are the glucose and total proteins content. It was observed increased enzymes activities in fish exposed to phenol. The total liver protein content was significantly reduced, which indicates tissue proteolysis; i.e., phenol induced protein consumption. Also, the liver glucose and glycogen were reduced. The liver of fish subjected to phenol showed high score of histopathological symptoms as inflammation, central necrosis and cell degeneration. These results indicated that phenol intoxication had antagonistic effects of fish health.

The Effect of Feeding Frequency on Growth Performance and Feed Conversion Rate of Black Sea Trout (Salmo trutta labrax Pallas, 1811)

Abstract: Growth and feed conversion are two critical variables determining the success in fish culture. Nutrition is one of the most important factors influencing the ability of cultured fish to exhibit its genetic potential for growth and reproduction. They are also greatly influenced by factors such as behaviour of fish, quality of feed, daily ratio size, feed intake or water temperature. Since the feed cost accounts approximately 40-60% of the operating costs in intensive culture systems (Anderson et al., 1997), the economic viability of the culture operation depends on the feed and feeding frequency. It means that nutritionally well-balanced diets and their adequate feeding are the main requirements for successful culture operations. Commercialized feed presented to cultured species is not only nutritionally well-balanced, but also readily ingested with minimum waste production and digested and converted to live weight in a predictable manner (Okumuş, 2000; Hasan, 2001). Each species has its particular food preferences and feeding behaviours. Feeding behaviour of fish is quite complex. Feeding and ingesting are the final result of a number of interacting factors between the fish (senses and hormonal systems) and its environment (stock density, size range or variability, season, day length, time of the day). In general, feed management or feeding techniques have two main objectives: i) to encourage rapid and positive consumption and thus reducing leaching of nutrients wastage; ii) to provide greater potential for growth by minimising the metabolic costs. The amount of the daily feed ratio, frequency and timing of the feedings and presentation of the predetermined ratio are the key factors of feed management strategies, influencing the growth and feed conversion (Jobling, 1995; De Silva and Anderson, 1995; Goddard, 1996). Thus these may be accepted as the major tools for materialising abovementioned objectives. Kaushik and Gomes (1988) observed that even under maintenance or zero growth conditions, frequent feeding reduced excretory losses of nitrogen, optimising the amount of nutrients and metabolic fuel made available for growth. Optimal feeding frequency may vary depending on species, age, size, environmental factors, husbandry, and feed quality (Goddard, 1996). Chiu (1989) summarised some of the experimental data available on feeding frequency at which optimal growth was observed in different fish species. The author noted the daily feeding frequency for rainbow trout fingerlings on 7.6-16.0 g. Piper et al. (1982) suggested three times daily feeding for 15.1-45.0 g rainbow trout fingerlings. The limited information available suggests that optimum feeding rates and frequencies should be determined for each species and different sizes of the same species cultured under various environmental and husbandry conditions. Black Sea trout is a new finfish species for intensive aquaculture (Tabak et al., 2001) and, the present study aimed at determining Abstract

Storage Properties of Three Types of Fried Whiting Balls at Refrigerated Temperatures

Abstract: In this study three types of fried fish balls from whiting (Merlangius merlangus euxinus, Nordmann, 1840) were assessed for sensory and chemical quality changes over a period of 15 days of refrigerated storage at 4oC. The total volatile basic nitrogen (TVB-N) content, thiobarbituric acid (TBA) and trimethylamine (TMA) values increased significantly (p<0.01), while sensory attributes decreased during storage. TVB-N and TBA results for products remained under the limit for edibility. However, the TMA values of fried fish balls made from both plain mince and surimi reached the upper acceptability limit on the 10 th day of storage. Sensory values showed that fish balls from plain mince had the shortest shelf life of 9 days, while the products originating from pre-cooked mince showed the longest shelf life, 11 days. Use of different types of mince in the fish balls had a significant effect on the quality of the products during the storage period (p<0.05).

Helminth Bioload of Chrysichthys nigrodigitatus (Lacepede 1802) from Lekki Lagoon Lagos, Nigeria

Abstract: Two hundred and sixty randomly selected specimens of a common fish, Chrysichthys nigrodigitatus (Lacepede 1802) collected over a period of one year from Lekki Lagoon, Lagos were subjected to parasitological examinations. The prevalence of helminth infections was 12.7%. Thirty three (33) of the fish specimens examined were infected with gastrointestinal helminth parasites. A total of seventy eight (78) parasite specimens were recovered from the fish specimens examined. The males (205) recorded a lower rate of infection (10.7%) than the females (55) which had a prevalence of 20%. Helminth parasites recovered include a cestode, Proteocephalus sp, an aspidogastrid trematode, Aspidogastrea africanus, and a nematode Paracamallanus cyathopharynx. Worm burden and intensity were low and independent of sex and age of fish. No seasonal variation in parasite intensity was observed.

Fecundity on Mystus bleekeri (Day, 1877) from the River Padma Near Rajshahi City

Abstract: The composition of phytoplankton community of Karagol Lake was studied between April-October 2001 and April-October 2002. Thirty-two taxa (21 belonging to Bacillariophyta, 8 to Chlorophyta, 1 to Cyanophyta, 1 to Chrysophyta and 1 to Euglenophyta) were determined. Some physical factors, such as ice, light and temperature affected development of the phytoplankton community. In addition, wind and water current caused mixing between phytoplankton and benthic algae.

A Preliminary Assessment and Management of Gilthead Bream Sparus aurata in the Port Said Fishery, the Southeastern Mediterranean, Egypt

Abstract: A total of 1714 gilthead bream Sparus aurata was collected from the Port Said fishery between January 2004 and February 2005. Total length ranged from 10 to 35.5 cm while total weight varied from 18 to 650 g. The length-weight relationship parameters were a = 0.0123 and b = 3.0284. The age distribution covered age groups 0 to IV. The parameters of the von Bertalanffy growth function in length were K = 0.5 year -1 , L∞ = 37.98 cm and t0 = -0.6 years. The rates of total (Z) and natural mortality (M) were 1.95 and 0.62 year -1 , respectively. The fishing mortality (F) was 1.33 year -1 and exploitation rate (E) of 0.68 indicated that the population has been heavily exploited. The estimated total length at first capture (Lc) was 11.1 cm, while the total length at 50% maturity (Lm) was 25.77 cm. The reproductive activity of gilthead bream in the Port Said fishery took place between November and February, with the greatest intensity in December. Yield per recruit analysis revealed over-fished stock conditions particularly due to small fish being effectively unprotected by the current minimum size regulations.

Survival and Growth of Macrobrachium rosenbergii (de Man) Juvenile in Relation to Calcium Hardness and Bicarbonate Alkalinity

Abstract: Survival and growth of Macrobrachium rosenbergii juvenile (0.045±0.007 g, 25 days old) were investigated under different calcium hardness levels from 92 to 384 mg/L CaCO3 for 42 days. The maximum survival rate (100%) was observed at a calcium hardness level of 92 mg/L CaCO3, while the lowest survival rate (60%) was recorded at the highest calcium hardness level of 384 mg/L CaCO3. Maximum growth of the prawn (11.6±2.7 mg/day) was observed at 132 mg/L CaCO3. However, there were not significant (P>0.05) changes in growth at calcium hardness levels of 92 and 192 mg/L CaCO3. The growth of the prawn declined significantly (P<0.05) at calcium hardness level of 228 mg/L CaCO3 and above. Survival and growth study of M. rosenbergii juvenile (0.12±0.03 g, 60 days old) was also done under different bicarbonate levels from 100 to 370 mg/L CaCO3 for 60 days. Survival rate of the prawn was highly impaired at the highest bicarbonate levels tested while maximum survival rate (90%) was recorded at bicarbonate level of 100 mg/L CaCO3. The highest growth (4.92±0.13 mg/day) of the prawn was recorded at lowest bicarbonate level of 100 mg/L CaCO3 tested and the growth significantly (P<0.05) declined at 205 mg/L CaCO3 bicarbonate alkalinity and above.

Distribution of Ligula intestinalis (L.) in Turkey

Abstract: In the present study, besides identifying host fish species and water resources in which it is reported that an important cestod species, Ligula intestinalis, exists as endoparasite in fish, inhabiting Turkish waters; our findings are given as new records.

The Fish Fauna of the Göksu River (Türkiye): Taxonomic and Zoogeographic Features

Abstract: In order to establish the taxonomic and zoogeographic features of the fish fauna of the Goksu River Basin, fish samples were collected using electrofishing equipment, gill nets, trammel nets, seine nets and cast nets in October 2004 and May 2005. Among the samples, ten species and three subspecies belonging to seven families were identified: Anguilla anguilla, Sardinella aurita, Salmo trutta macrostigma, Cyprinus carpio, Barbus capito pectoralis, Capoeta capoeta angorae, Chondrostoma regium, Species from Gobio gobio group, Seminemacheilus cf. ispartensis, Clarias gariepinus, Mugil cephalus, Liza ramado and Liza saliens. The most dominant family in the river and its branches are the Cyprinidae with three species and two subspecies.

A Study on the Milt Quality of Oncorhynchus mykiss (Walbaum, 1972) and Carasobarbus luteus (Heckel, 1843) in Atatürk Dam Lake, Southeastern Turkey

Abstract: The aim of this study was to determine the milt quality of Oncorhynchus mykiss (Walbaum, 1972) and Carasobarbus luteus (Heckel, 1843). Milt was collected twice by abdominal massage during the spawning seasons of the species. Volume, forward motility, duration of motility, milt concentration and pH were determined in milt collected. Body weights and lengths of brood fish were also measured. Milt volume (ml), forward motility (%), the duration of motility (sec), concentration (x10 9 cell/ml) and pH values were 1.22±0.22 and 0.80±0.06, 73.25±5.15 and 55.50±4.59, 90.80±10.40 and 175.80±17.00, 6.06±0.90 and 11.29±1.46, 7.99±0.03 and 8.07±0.12 for O. mykiss and C. luteus, respectively. The spermatozoa concentration of O. mykiss, and duration of motility, spermatozoa concentration and sperm pH of C. luteus were affected significantly by milt stripping dates (P<0.05, P<0.01). The results suggested that the spermatozoa concentration of O. mykiss, and duration of motility, spermatozoa concentration and sperm pH of C. luteus were affected by stripping dates.

Effects of Variations in Feed and Seasonal Changes on Body Proximate Composition of Wild And Cultured Sea Bass (Dicentrarchus labrax L.)

Abstract: In this study, the effects of dietary composition and seasonal variation on fillet composition and some morphological indices of wild and cultured sea bass (average weight, 361 g) were investigated. Experimental fish were fed with two commercial pelleted feeds and two commercial extruded feeds in summer, winter and spring seasons of year 2004 at four marine fish farms in Aegean region in Turkey. No significant differences were found among the proximate composition of feed samples, seasonally. The crude protein content (about 45%) in the commercial feeds was found similar (P>0.05), whereas the crude fat content (about 20 %) in the extruded feeds was significantly higher (P 0.05) were found in the condition factors (CF) of the cultured and wild sea bass neither among different feeds nor among different seasons. The viscerosomatic index (VSI) and hepatosomatic index (HSI) values or visceral and liver lipid content of fish fed with the extruded feeds were higher (P 0.05) to the values of fish fed with lower fat diet. The visceral lipid content of cultured and wild fish significantly increased in summer, while the liver lipid content significantly increased in winter (P 0.05) were found in the ash content of the cultured and wild sea bass neither among different feeds nor among different seasons. Crude protein levels of the fish fillet did not differ (P>0.05) among the fish fed with different commercial feeds or during different seasons, although the crude protein levels in the cultured fish were significantly higher (P<0.05) than that of the wild fish. A high positive correlation (r = 0.84, P0.05) by different seasons whereas the fillet lipid content of the wild fish during summer was slightly higher (P<0.05). Finally, the results of chemical analysis showed that the fillet composition of cultured and wild sea bass were good sources of protein and lipid in each of the three seasons.

Pond Culture of Penaeus semisulcatus and Marsupenaeus japonicus (Decapoda, Penaeidae) on the West coast of Turkey

Abstract: Postlarvae of Penaeus semisulcatus and Marsupenaeus japonicus were grown for 150 days at a stocking density of 15 shrimps/m 2 on the west coast of Turkey. At the end of the culture period, P. semisulcatus and M. japonicus reached to mean weights of 16.46 g and 7.05 g, respectively. Final yield and survival for P. semisulcatus were 1950 kg/ha and 79%, while these figures for M. japonicus were 655 kg/ha and 62%. The FCR was 2.42 for P. semisulcatus and 3.50 for M. japonicus. The result indicated that P. semisulcatus had better growth performance, final yields and survival rates.

Age, Growth and Mortality Rate of the Narrow-Barred Spanish Mackerel (Scomberomerus commerson Lacepède, 1800) in Coastal Waters of Iran from Length Frequency Data

Abstract: Monthly data of length composition for narrow-barred Spanish mackerel, Scomberomorus commerson (Lacepede), landed between April 2003 to March 2005 along the Persian Gulf and Oman Sea were used to estimate the growth, mortality and exploitation parameters of the stock. Maximum fork length and weight were 132 cm and 18.4 kg respectively. Nonlinear least square fitting provided a complete set of von Bertalanffy growth estimates: L∞=140 cm fork length; K=0.42 and t0= -0.26 years. The estimated value of total mortality based on length converted catch curve using these growth parameters is Z=1.47 year-1. Natural mortality based on growth parameters and mean environmental temperature (T=26.5oC) is M=0.49 year-1. Furthermore, the annual instantaneous fishing mortality rate of 0.98 year-1 was by far in excess of the precautionary target (Fopt=0.49 year-1) and limit (Flimit=0.65 year-1) biological reference points, indicating that the resource was heavily over-exploited, and that management of this species should have been implanted rapidly if they were to remain sustainable.

Commercial Fishery Impact on the Modern Black Sea Ecosystem: a Review

Abstract: During the last 30 - 40 years the Black Sea ecosystem has been found subjected to diverse anthropogenic factors. Among one of it appears to be the fishing pressure. Up till recently no common viewpoint is available regarding its influence on the ecosystem. The main objective of the study is to evaluate the role of commercial fishery in structural and functional alterations of the Black Sea ecosystem on a basis of a data-series relative to long-term dynamics of fisheries statistics and biological population indices.

Diet and Growth of 1+ Siberian Sturgeon, Acipenser baerii in Alternative Pond Culture

Abstract: The culture of 1+ Siberian sturgeon (Acipenser baerii) was performed in concrete storage ponds with natural water temperature regime during the growing season. Fish were separated into two groups - with supplementary feeding using trout pellets (FF) and control variant (CF). Specific growth rates in FF and CF were 0.26 and 0.16%.day-1 in length and 0.53 and 0.18%.day-1 in weight, respectively. The average indices of weight condition rose from initial 0.377 and 0.372 to final values of 0.393 and 0.322 in FF and CF, respectively. Fish diet consisted of 25 food items. Chironomid larvae, cladocerans (Daphnia sp.) and detritus prevailed in fish guts with 40.4 - 52.8, 19.1 - 28.8 and 16.3 - 19.4%, respectively. Pelleted feed occurred in 8.7% proportion in one third of examined FF fish. The highest indices of preponderance were found for chironomid larvae (40.06 - 62.90) and Daphnia (17.50 - 29.00). The index of preponderance for artificial feed was only 3.53; however, its role in the growth performance and condition of Siberian sturgeon in pond culture was very important.

The Oligochaeta (Annelida) Fauna of Yuvarlak Stream (Köyceğiz-Turkey)

Abstract: To detect the distribution of Oligochaeta fauna of Yuvarlak Stream in the Koycegiz-Dalyan protected area in SouthWestern Turkey, monthly samplings were made from 11 stations from May 2001 to April 2002. The samples were collected by using 180 µ and 500 µ mesh size hand nets and an Ekman-Birge Grab in 9th and 10th stations. As a result of the study, totally 50 taxa comprised of 17 species from Tubificidae, 28 species from Naididae, 3 species from Enchytraeidae and 2 species from Lumbriculidae were determined. Tubifex newaensis, Nais alpina and Nais behningi are new records for the inland water fauna of Turkey.

Cladocera and Copepoda (Crustacea) Fauna of İkizcetepeler Dam Lake (Balikesir, Turkey)

Abstract: Cladocera and Copepoda (Crustacea) fauna of Ikizcetepeler Dam Lake were studied by monthly sampling between August 2004 and May 2005. Examination of the samples revealed a total of 12 species, composed of eight cladoceran and four copepod species.

A Taxonomic Study on the Phytoplankton in the Littoral Zone of Karagöl Lake (Borçka-Artvin/Turkey)

Abstract: The composition of phytoplankton community of Karagol Lake was studied between April-October 2001 and April-October 2002. Thirty-two taxa (21 belonging to Bacillariophyta, 8 to Chlorophyta, 1 to Cyanophyta, 1 to Chrysophyta and 1 to Euglenophyta) were determined. Some physical factors, such as ice, light and temperature affected development of the phytoplankton community. In addition, wind and water current caused mixing between phytoplankton and benthic algae.

Investigation of Some Population Parameters of the Tench (Tinca tinca L., 1758) Inhabiting Beyşehir Lake (Konya-Turkey)

Abstract: This study was carried out between April, 2004 and March, 2005 in Beysehir Lake in the Central Anatolian Region of Turkey. The present study of 210 Tinca tinca from Beysehir Lake shows that 52.38 % are female and 47.62 % male ranging between I+-VIII age groups. The sex ratio was 1.10 female:1 male in the studied samples. Specimens ranged from 14.9 to 38.5 cm in fork length, and 48.5 to 967.10 g in weight. At the same time, fork length and weight distributions of Tinca tinca were also given in this study. Age-length and age-weight relations were calculated by the von Bertalanffy growth formula. The following equations were found for males and females, respectively. Lt=41.36[1- e1-0.152(t+3.1396)], Lt=44.23[1- e1-0.1176(t+3.6745)],Wt= 1202.16 (1- e-0.52(t+3.1396 )3.0993, Wt=1458.30 (1- e-0.1176 (t+3.6745) )3.0718.