Lake Manyas Research Articles

Threatened Fishes of the World, Cobitis puncticulata (Erk’akan, Atalay-Ekmekçi & Nalbant, 1998) (Cobitidae)

Keywords Cobitis puncticulata.Brownspinedloach.Distribution.WesternAnatoliaCommon name: Brown spined loach (English) Kah-verengi copcu baligi (Turkish). Conservation status:Critically Endangered (IUCN 2009). Identification:Brownish body, consisting only of small dark-greydots through the body and head and blotches of Z2and Z4 (Gambetta 1934) are very small, indistinct orconfluent (Kottelat and Freyhof 2007). A strong keelis present above and below the caudal peduncle.Sexually dimorphic; males have one lamina circularisor scale of Canaestrini in the second pectoral fin ray(Erkakan et al. 1998). Females up to78 mm SL, malesare smaller. Distribution: Apart from the Kocacay andthe Karadere from the Manyas (Kus) Lake drainage(Erk’akan and Ekmekci 2000), recorded from theRiver Evros in Greece (Thrace) and in the UluabatLake catchment in the east of Manyas Lake (Freyhofet al. 2008). In 2005, we found this species inBakacak Stream a tributary of the Kocabas drainage(Marmara Sea) in Canakkale (Ekmekci et al. 2008).Abundance: Recorded as rare by IUCN (Crivelli 2006).Habitat and ecology: Still to moderate flowingstreams, with muddy or sand substrate. Reproduction:No data, only known to spawn in spring. Threats:InTurkey, pollution and flow regulation are the mostimportant threats, with decline of the habitat qualityand further loss of habitat. No threats were recorded inthe lower Evros. Conservation recommendations:Water level change causing habitat loss should becontrolled. Detailed information is required on thepopulation size and biology. Remarks: After recordingC. puncticulata from two new localities, Freyhof et al.(2008) suggested changing the status to “vulnerable”.We have recently extend the range of this species to a

Reproductive efficiency of the narrow-clawed crayfish, Astacus leptodactylus, in several populations in Turkey

Studies were carried out to evaluate the reproductive efficiency of the narrow-clawed crayfish, Astacus leptodactylus Eschscholtz, 1823, in three different populations in the lakes Apolyont, Iznik, and Manyas in Turkey. Crayfish were sampled monthly using fyke-nets of 34 mm mesh size from April 2002 until March 2003. The average number of pleopodal eggs (with their range), per female, was 200 ± 12 (8-556) in Lake Apolyont, 202 ± 13 (6-350) in Lake Iznik, and 257 ± 13 (18-465) in Lake Manyas. The average number of ovarian eggs (with their range), per female, was 348 ± 20 (126-630) in Lake Apolyont, 305 ± 11 (162-465) in Lake Iznik, and 400 ± 18 (205-776) in Lake Manyas. The average egg diameter and ranges were 2.23 ± 0.004 (1.80-2.98) mm in Lake Apolyont, 2.53 ± 0.003 (2.06-2.92) mm in Lake Iznik, and 2.65 ± 0.027 (1.98-3.04) mm in Lake Manyas. Neither egg diameter nor egg weight increased with body size, but the variability of egg size and weight was high. No relationship was found between egg size and female crayfish size for any of the lakes. Mean size at maturity of female A. leptodactylus varied among the lakes. Females in Apolyont populations reached sexual maturity at a size of 64.3 mm TL, but spawning occurred only when females attained 82-128 mm TL, indicating that the mean minimum reproductive size was 82 mm TL in Lake Apolyont. Average female size was 88.7 mm (±SD 0.6; max. 142 mm; min. 48 mm; n = 154). In Iznik Lake, size at maturity of females was 78 mm TL, while spawning size was 83142 mm TL; average female size was 90.6 mm (±SD 0.5; max. 139 mm; min. 66 mm; n = 99). Finally, female size at maturity was 72.6 mm TL, and spawning size was 80-130 mm TL in Manyas Lake; average female size was 89.0 mm (±SD 1.1; max. 141 mm; min. 29 mm; n = 122). The total observed sex ratio (male/female) was found to be 1.00/0.53 in all three lakes together. Mature A. leptodactylus reproduce only once a year under natural conditions. No evidence was found in this study to suggest the occurrence of multiple spawnings.

Spatial and temporal dynamics of the steady-state phytoplankton assemblages in a temperate shallow hypertrophic lake (Lake Manyas, Turkey)

Spatial and temporal dynamics of phytoplankton biomass and species composition in the shallow hypertrophic Lake Manyas, Turkey, were studied biweekly from January 2003 to December 2004 to determine steady-state phases in phytoplankton assemblages. Steady-state phases were defined when one, two or three coexisting species contributed to at least 80% of the standing biomass for at least 2 weeks and during that time the total biomass did not change significantly. Ten steady-state phases were identified throughout the study peiod. During those periods, Achnanthes microcephala (Kutzing) Cleve twice dominated the phytoplankton biomass alone and contributed to more than 50% of the total biomass in seven phases. Microcystis aeruginosa (Kutzing) Kutzing, Anabaena spiroides Klebahn, Cyclotella stylorum Brightwell, Pediastrum boryanum (Turpin) Meneghini and Phacus pusillus Lemmermann were also represented once in steady-state phytoplankton assemblages. A. microcephala was dominant usually during cold periods of the year, while M. aeruginosa and A. spiroides were usually dominant in warm seasons. The total number of species showed a clear decrease during steady-state phases at all stations. All stations were significantly different in terms of the measured physical and chemical parameters (P < 0.05) and phytoplankton biomass (F = 117, P < 0.05).

Effects of water quality and hydrologic drivers on periphyton colonization on Sparganium erectum in two Turkish lakes with different mixing regimes

The aim of this paper is to determine and compare the environmental factors controlling vertical colonisation of periphyton on Sparganium erectum in a shallow eutrophic turbid lake, Manyas Lake, and an oligo-mesotrophic deep lake, Sapanca Lake, Turkey during the July 1997--November 1998. To investigate the effect of the environmental factors on periphyton colonization on S. erectum, the stem was cut above the rhizomes and subdivided into three equal sections. Multivariate statistical analyses have been applied to clarify relationships between environmental variables and periphyton colonization on S. erectum. Results indicated that physical disturbance and trophic level of the lakes influenced the colonization of the periphyton. Among the measured parameters, low light intensity, total suspended solids, temperature and water level fluctuation were observed as driving factors in Manyas Lake whereas nutrient deficiency was found as key factor in Sapanca Lake. The zonation of the periphyton, density, composition and dominant/subdominant taxa were significantly different in these lakes. However, Oedogonium sp., Mougeotia sp., Cylindrocapsa sp., Cladophora glomerata (Linn.), Aulacoseira italica (Ehr.) Simonsen, Melosira varians C. Agardh, Navicula tripunctata (O.F. Müller) Bory and Fragilaria ulna (Nitzsch) Lange-Bertalot were found as dominant species at all sections of S. erectum both in Manyas Lake and Sapanca Lake. It can be thought that these species have a broad range of tolerance to several physical, chemical and hydrologic disturbances. This is the first study to introduce how much the water quality and hydrologic drivers have affected vertical colonization of periphyton on S. erectum in two lakes with different mixing regimes.

A travel cost study to estimate recreational value for a bird refuge at Lake Manyas, Turkey

This paper investigates the recreational economic value of bird watching in the Kuşcenneti National Park (KNP) at Lake Manyas, one of the Ramsar sites of Turkey and an important endangered species habitat. The lake and KNP provide considerable benefits for the region, although they have faced many environmental conflicts due to diverse stakeholders’ needs. An economic valuation for the benefits provided by the KNP is important data for stakeholders and local authorities. The travel cost method is used to estimate recreational demand for the KNP. The recreational value of the KNP is 103,320,074 USD annually. Results shed light on important policy issues and help to resolve conflicts among stakeholders. This calculated value is considerably higher than the annual investment and operation expenditures of the KNP. Sustainability of the important species around the lake could be achieved if the region's inhabitants are compensated by KNP visitors.

Seasonal Dynamics of Phytoplankton Assemblages across Nutrient Gradients in Shallow Hypertrophic Lake Manyas, Turkey

Species composition, abundance and size distribution (the average measure of the longest cell dimension and surface area to volume ratio) of phytoplankton in the shallow hypertrophic Lake Manyas, Turkey were studied between January 2003 and December 2004. A total of 165 species were recorded during the study. Diatoms and Cyanobacteria were the dominant taxa at most stations. Nitrate and phosphate values showed a decreasing gradient with the distance from Sigirci Inlet to Karadere Outlet. Bacillariophyta dominated the phytoplankton in spring, while Cyanobacteria prevailed in summer. Each summer, a peak of Euglenophyta was also observed at Sigirci Inlet. Nutrient gradients seemed to have a greater control over overall density than of species composition. The size distribution of the Cyanobacteria showed positive correlations with nutrient levels, while green algae and diatoms did not. There was a negative correlation between the average cell dimension of the phytoplankton cells and the surface area to volume ratio in general. The objective of this study was to determine the seasonal dynamics of species composition, abundance and size distribution of phytoplankton assemblages across nutrient gradients along a distance in the shallow hypertrophic Lake Manyas, Turkey.

The Relationships Between Certain Physical and Chemical Variables and the Seasonal Dynamics of Phytoplankton Assemblages of Two Inlets of a Shallow Hypertrophic Lake with Different Nutrient Inputs

The relationships between water discharge, temperature, total dissolved solids (TDS) conductivity, turbidity, nitrate, ammonium, phosphate and the seasonal dynamics of phytoplankton assemblages of two inlets of a shallow hypertrophic lake (Lake Manyas, Turkey) were studied between January 2003 and December 2004. The results showed that different levels of water discharge, turbidity, conductivity, TDS and nutrients could lead to the development of significantly different phytoplankton assemblages in inlets of shallow hypertrophic lakes. The multiple regression analysis identified water discharge, turbidity and water temperature as the driving factors behind the dynamics of phytoplankton biovolume in the studied inlets. The first two axes of Canonical Correspondence Analysis (CCA) explained 78% of the total variance in dominant phytoplankton species at Siğirci Inlet and 88% at Kocaçay Inlet, respectively. The purpose of this study was to determine the relationships between water discharge, temperature, conductivity, turbidity, pH, TDS, nitrate, ammonium, phosphate and the seasonal dynamics of phytoplankton assemblages of two inlets of the shallow hypertrophic Lake Manyas, Turkey by means of multivariate statistical analysis.

Spatial and Seasonal Variations in Chlorophyll-Nutrient Relationships in The Shallow Hypertrophic Lake Manyas, Turkey

Regression and correlation analyses were used to predict responses of phytoplankton biomass (chlorophyll) (microg L(-1)) to nitrate (NO(3)) (mg L(-1)), phosphate (PO(4)) (mg L(-1)) and ammonium (NH(4)) (mg L(-1)) dynamics in the shallow hypertrophic Lake Manyas, Turkey. Nutrient concentrations showed a descending gradient with distance, while chlorophyll concentrations showed an ascending gradient with the distance from the Siğirci Inlet to the Karadere Outlet. Higher nutrient concentrations did always not coincide with higher chlorophyll concentrations. The results showed that regression models developed using seasonal data were more accurate in predicting chlorophyll concentrations than those developed using the pooled data from whole year (based on R (2) and the difference between the measured and predicted values). The findings also revealed that within a single large shallow lake, chlorophyll-nutrient relationships might show significant variations spatially. The objective of this study was to determine the seasonal and spatial variations in the relationships between chlorophyll, nitrate, phosphate and ammonium in the shallow hypertrophic Lake Manyas, Turkey.

Determination of traits some growth and morphometric of crayfish (Astacus leptodactylus Eschscholtz, 1823) at Manyas Lake (Balıkesir).

Determination of traits some growth and morphometric of crayfish (Astacus leptodactylus Eschscholtz, 1823) at Manyas Lake (Balıkesir).

Sulfur-isotope distribution and contamination related to the Balya Pb?Zn Mine in Turkey

Sulfur-isotope (δ34S) values and weight (%) of acid-volatile sulfur (AVS), chrome-reducible sulfide (CRS), elemental sulfur (ES), and acid-soluble sulfates were determined in Balya Mine ore rock, mine wastes, and Kocacay River and Lake Manyas sediments. Estimation of isotopic fractionation (Δ34S) between product sulfate and initial CRS (pyrite) was used to evaluate the progress of sulfide oxidation in the mine-waste area. Water- and acid-soluble sulfate produced from different mine-waste samples, such as metallurgical waste (MW) and waste rock (WR), in laboratory experiments also shows distinct δ34S values and allows identification of the acid-mine-drainage sources in the mine-waste area. Average δ34SSO4values are −1.43‰ for MW (n=4) and +2.06‰ for WR (n=8). Short (24 hr) and long (60 days) term leach experiments were considered using alternating wet/dry conditions to simulate sulfate-production capacity and metal-discharge characteristics for MW and WR piles. Release of heavy metals follows the order of Pb2+ >Mn2+ >Zn2+ >Cu2+ for these pile samples. Values of δ34SSO4 for river water that was collected after 3–4 h of heavy rainfall are close to values of δ34SSO4 for water-soluble sulfates from mine-waste piles used in laboratory leach experiments.

Physical, Chemical and Microbiological Water Quality of the Manyas Lake, Turkey

Manyas, also known as the Bird Paradise Lake, is situated near the south-eastern coasts of the Marmara Sea in Turkey. This shallow lake, is a unique natural reserve providing habitat for migratory birds with its rich fauna and plankton species. The objective of this work is to study the ecological and water quality changes resulting from increasing anthropogenic pollution and human intervention on the natural variations of the water level. For this purpose, physical, chemical and microbiological aspects of the aquatic ecosystem in the lake of Manyas are being measured semi- monthly since more than a year. After the completion of field measurements associations between different parameters will be searched by means of a water quality model. Results obtained will be used in the sustainable restoration of the lake. In this paper, firstly the nutrient and trophic dynamics of the planktonic ecosystem are associated with the bio-geochemical water cycle in the lake. Secondly, space and time distributions of all physical, chemical and microbiological data are presented and interactions between the nutrient availability and some microscopic communities are discussed.

Late Holocene erosion in NW Anatolia from sediments of Lake Manyas, Lake Ulubat and the southern shelf of the Marmara Sea, Turkey

This paper deals with modern and ancient sedimentation in fresh water lakes and the marine shelf of the southern Marmara region, NW Anatolia, Turkey. Most of the information has been obtained from monitoring of suspended load discharged into two lakes (Manyas and Ulubat) in the last 45 years and from 8 to 11 m thick lacustrine sediments, in addition to radiocarbon-dated shelf sediments. This allows a holistic approach to the drainage basin denudation over time. The results show that the sedimentation rates in the lakes were low 0.22 cm year −1, from 4000 to 2000 years BP and then they increased (0.29 cm year −1) up to sub-recent times and reached 0.44 cm year −1 in the last century. It is suggested that deforestation created high rates of sedimentation in the basins and/or strong denudation of the region during the Late Holocene. This study also shows that for shallow freshwater lakes the calculation of sedimentation rates must include fine particles lost by the outlets and coarse-grained bed load deposited on their shores. In addition, a high rate of sedimentation has been created by short, but repetitive intense depositions. During the last century particularly during the last 45 years, the rate of sedimentation or denudation has increased dramatically in NW Turkey. The two World Wars and mismanagement of the land had important local effects by increasing deforestation and resulting in the present erosive conditions.

Heavy metal pollution and acid drainage from the abandoned Balya Pb-Zn sulfide Mine, NW Anatolia,Turkey

This study was conducted to determine the effects of the waste-rock dump (WRD) of the underground polymetallic Balya Mine on the Kocacay River and eventually on Lake Manyas in Turkey. Data presented in this paper include geochemical characteristics of various kinds of water (mine, surface and groundwater) and of suspended-particle samples in the vicinity of Balya. The more polluted mine waters have low pH and high conductivity, while high concentrations of Zn, Cd, Mn tend to be found in the dry and wet seasons. High concentrations of Pb, As, Cr, Cu and S appear only in the wet season. The sources of the heavy metal concentration within the Kocacay River are leached waste, surface run off, and overflow from the spillway of the WRD. To minimize the formation of acids and dissolved metal, and for the remediation of the harmful effects of extreme contamination conditions, it is recommended that lime or alkali materials and organic carbon be added to simulate the action of sulfate-reducing bacteria.

Trace Metal Levels In Surficial Sediments Of Lake Manyas, TURKEY AND TRIBUTARY RIVERS

Some trace element contents of surficial sediment samples from sampling stations in Lake Manyas (Bird Lake) in Turkey and its tributary rivers have been analyzed by flame atomic absorbtion spectroscopy. The mean levels (μgg −1 dry weight) of Mn, Fe, Cu, Pb, Ni, and Zn for five sampling stations in the first season (March 1996) and for eight sampling stations in the second season (May 1996) have been listed. The results have been compared with the values given in the literature. A comparison with the available benchmark sediment quality criteria and toxicity guideline values has also been made. The results in the light of those comparisons suggest that a pollution problem especially with respect to Cu, Pb, Zn and Ni exists at several stations which are effected by municipal and industrial effluents and at the middle of the lake.

Abrupt environmental changes within a late Holocene lacustrine sequence south of the Marmara Sea (Lake Manyas, N-W Turkey): possible links with seismic events

A coring campaign in Lake Manyas (Kuş Gölü) on the southern coast of the Sea of Marmara (Turkey) has provided insights into basin infilling processes during the upper 11 metres of the sedimentary record. Combined sedimentary features between 5 and 4 m depth have been explained by a seismite. A brittle mixed layer (uniquely rich in seeds and ostracod valves) was widely detected at 4 m downcore. This has been interpreted as being the result of a seiche either through a salt inundation linked to a tsunami in the Sea of Marmara (the large-scale scenario) or a local hydrothermal fluid discharge (the small-scale scenario). Ostracod valves, which are usually not preserved in Lake Manyas sediment, are either incorporated here as tsunami debris (providing a spatially averaged snapshot of the regional assemblage) or are locally preserved following a temporary geochemical/hydrochemical change of the water of unknown duration (but probably several decades). The brittle mixed layer overlies cracks resulting from the direct effects of the seismic shock wave on slightly compacted sediment. At around 964 cm depth palynological and particle-size analyses indicate a change from backswamp to open lacustrine conditions. The end of the backswamp has been correlated with a decrease in the level of the Sea of Marmara from 4000 to 3000–2800 yr ago (uncal.), caused by regional tectonic movements. An age–depth model is presented based on two AMS radiocarbon dates, on the palynological detection of the end of the Beyşehir Occupation Phase (130 cm above the event) and on maximal sedimentation accumulation rates obtained by radionuclide analyses. The entire study sequence covers the last 4300 yr. The paper examines the possibility of an Early Byzantine age for the seismic event. This may have been the historical event at AD 460 that destroyed Cyzicus (the ancient Erdek, 20 km north of the lake) and various villages in the interior and was felt widely in the then-known world. Other possibilities include various local and regional events in that same period: the Early Byzantine Tectonic Paroxysm and the large earthquake in AD 447 that affected the entire Sea of Marmara region.

Trace metal levels in surficial sediments of Lake Manyas, Turkey and its tributary rivers

Some trace element contents of surficial sediment samples from sampling stations in Lake Manyas (Bird Lake) in Turkey and its tributary rivers have been analyzed by flame atomic absorption spectroscopy. The mean levels (pgg ' dry weight) of Mn, Fe, Cu, Pb, Ni, and Zn for five sampling stations in the first season (March 1996) and for eight sampling stations in the second season (May 1996) have been listed. The results have been compared with the values given in the literature. A comparison with the available benchmark sediment quality criteria and toxicity guideline values has also been made. The results in the light of those comparisons suggest that a pollution problem especially with respect to Cu, Pb, Zn and Ni exists at several stations which are effected by municipal and industrial effluents and at the middle of the lake.

Dascylium

The identification of the lakes of the Cyzicene and the determination of the site of Dascylium, the seat of the Hellespontine satraps, are problems which have worried every scholar who has had to deal with the history or geography of the district. They are inseparable, because not only the names themselves, but also the statements of our ancient authorities, prove that Dascylium involves the neighbourhood of a Dascylite lake, and the Dascylite lake the neighbourhood of a Dascylium. Investigators have generally adopted one of two theories. Those who, like Dr. Richard Kiepert, have started from a place Dascylium, have fixed it at Daskeli or Diaskeli (Yaskil, Eskil Liman), a roadstead and village on the coast midway between Mudania and the Rhyndacus, and have conjured up a vanished lake in the valley of the Ulfer or Nilufer a few miles to the south. Since the publication of Heinrich Kiepert's large map this view has become an accepted tradition, and still holds the field. Those on the other hand who have started from a lake have usually found it in Lake Manyas, 10 or 12 miles south of Panderma, and have cast about for a site for Dascylium in its vicinity. Mr. F. W. Hasluck discusses the problems in his scholarly book on Cyzicus and the country adjacent to it, and regards this latter solution as the more probable of the two, but hazards a conjecture that Dascylium is perhaps to be sought farther eastward near Brussa. Some new evidence which has lately accrued from the recently published Hellenica Oxyrhynchia and from archaeological discoveries justifies a fresh examination of the questions.