THE STORY OF THE CUTE GHOSTS IN A SHALLOW LAKE: ZOOPLANKTON

Shallow lakes are ecologically and economically important ecosystems because they are significant for biodiversity and they provide many ecosystem services, but most of them are under the eutrophication and desiccation hazard. The first approach towards the evaluation of ecologic conditions of a lake is to determine the patterns of the biological communities, and zooplankton is one of the best indicators. Zooplankton have an important position in the food web between the upper and lower layers both as prey and consumer. Therefore, the determination of species composition and the diversity of zooplankton in a shallow lake can be used as a biological indicator of ecosystem health. In the present study, monthly (except snow covered months) zooplankton variation of Lake Hafik (Sivas, Turkey), and their interaction with the environmental conditions were studied for the first time. Lake Hafik is a mesotrophic lake based on its limnological variables. A total of 19 zooplankton species were recorded with Crustaceans (86% of the total zooplankton abundance) were being dominant. The main abundant taxa (N% > 5 of the total zooplankton abundance) were copepod nauplii, Arctodiaptomus bacillifer (Koelbel, 1885), Keratella quadrata (Müller, 1786), and Daphnia (Daphnia) cucullata Sars, 1862, respectively. The high density and biomass of the zooplankton were determined in May. In terms of diversity, Lake Hafik was not rich. Statistically, the rotifer density and biomass were mainly affected by physical variables (temperature, DO, and pH), whereas the crustaceans was primarily related to nutrients and EC

Eski Riva ve Bıçkı Dereleri’nin Zooplankton Faunası (İstanbulTürkiye)

Bu çalışmada, İstanbul’un en büyük içme suyu rezervuarının en önemli kaynakları olan Eski Riva ve Bıçkı Dereleri’nin zooplankton kommunite yapısı ve çeşitliliği Eylül 2006- Ağustos 2007 tarihleri arasında aylık olarak incelenmiştir. Ölçülen çevresel parametreler su sıcaklığı, elektriksel iletkenlik, çözünmüş oksijen ve pH’dır. Belirlenen çevresel parametre değerlerinin teşhis edilen organizmaların yaşamlarını sürdürmeleri için uygun olduğu ve Çevre ve Orman Bakanlığı’nın Su Kirliliği Kontrolü Yönetmeliği’ne göre derelerin su kalitesinin I. Sınıf olduğu tespit edilmiştir. Çalışmada 33 Rotifer, 3 Kopepod ve 4 Kladoser olmak üzere toplam 40 takson tespit edilmiştir. Her iki derede de Rotifera en bol bulunan grup olmuştur (Bıçkı Dere % 97.3, Eski Riva Deresi %83). Eski Riva Deresi’nde Euchlanis dilatata Ehr., Canthocamptus staphylinus (Jurine), Lecane (Monostyla) lunaris (Ehr.), Colurella colurus (Ehr.), Trichocerca (Diurella) porcellus (Gosse), Lepadella patella (O.F.M.), Trichocerca cylindirica (Imhof), Rotaria rotatoria (Pallas), Cephalodella gibba (Ehr.) ile Alona rectangula Sars ve Bıçkı Dere’de Lepadella ovalis (O.F.M.), T. (D.) porcellus, C. colurus, C. staphylinus ile A. rectangula çalışma periyodunda baskın türler olarak teşhis edilmiştir. Teşhis edilen zooplankton türleri açısından iki istasyon arasındaki benzerlik oranı %53.9 olarak belirlenmiştir. Teşhis edilen zooplankton türleri çalışma alanı için ilk kayıttır

INDICATOR ZOOPLANKTON SPECIES AND ECOLOGICAL REQUIREMENTS OF ZOOPLANKTON COMMUNITIES IN MAN-MADE RESERVOIRS

In the present study, eleven man-made reservoirs were visited between 17 and 20 June 2009 and 18 and 21 July 2010 to determine ecological requirements of zooplankton communities by major environmental variables (water temperature, dissolved oxygen concentration, pH, conductivity). The water temperature, dissolved oxygen concentration, pH, conductivity values during the study among the sites ranged between 15.6-28.3 degrees C; 7.94-13.4 mg L-1; 8.07-8.66; and 219-464 (mu S cm(-1)), respectively. Major limnological variables showed significant differences both temporally (between years) (except for DO and EC) and spatially (i.e. sampling sites) (p < 0.05). A total of 62 taxa of zooplankton represented by 41 Rotifera, 11 Cladocera, and 10 Copepoda was identified. The most common species were rotifers Keratella cochlearis (Gosse) (11 sampling sites), Asplanchna priodonta (Gosse) and Synchaeta oblonga Ehrenberg, Polyarthra vulgaris (Carlin) (10 sampling sites), cladocerans Bosmina longirostris (Muller) and Chydorus sphaericus (Muller) (11 sampling sites) and copepod Acanthocyclops venustus (Norman & Scott) (6 sampling sites). Predominant and also most of the other identified species in the present study were known as eutrophication indicators. Species richness (as total number of species) of the sampling sites changed between 9 (Utuk reservoir) and 27 (Kirazoglu reservoir). Abundances of main taxonomic zooplankton groups were similar but varied temporally and spatially. Sampling sites were determined as beta-mesosaprobic. Statistically, cladoceran C. sphaericus was determined as the indicator species throughout the study, which is common and resistant to the wide range conditions. The results of the present study are generally indicative of unpolluted waters. All of the identified zooplankton species are the first report for the studied water bodies

Zooplankton abundance in the lower Sakarya River Basin (Turkey): Impact of environmental variables

In the present study the community structure and diversity of zooplankton were investigated seasonally in the polluted water of the lower Sakarya River Basin during February 2008-January 2009. The environmental variables measured were river flow, water temperature, conductivity, dissolved oxygen, pH, suspended particulate matter, chlorophyll a and nutrients (NO2-N, NO3-N, SiO2, PO4-P, TP). Determined environmental parameters were at the suitable intervals for habitat choice of identified zooplankton species. Thirty-two zooplankton taxa were determined , which were mostly indicators of eutrophic water of the study area. Rotifera was the most abundant group (96.4%), followed by Copepoda (2.7%) and Cladocera (1.0%). The dominant taxa were Brachionus budapestinensis Daday, Keratella cochlearis (Gosse), Polyarthra vulgaris (Carlin), Synchaeta oblonga Ehrenberg and Trichocerca ruttneri Donner from Rotifera, Copepod nauplii from Copepoda and Bosmina longirostris (Müller) from Cladocera. Depending on the station, zooplankton abundance and environmental parameters showed seasonal variation. Generally, higher zooplankton abundance and higher temperature resulted in a higher zooplankton diversity index. Statistical analyses indicated that rotifers and total zooplankton were highly associated with environmental parameters, especially water temperature and nutrients. Degree of pollution determines the quality as well as the quantity of plankton in the study area. Consequently, waste waters should be controlled, and pollution must be prevented to conserve biodiversity of zooplankton fauna and in consequence food web of the study area. All zooplankton species identified were the first records for the study area

A Preliminary Study on Using Rotifera Fauna to Determine The Trophic Level of The Buyukcekmece Reservoir (istanbul, Turkey)

In this study, the abundance of rotifera fauna, in the Buyukcekmece Reservoir (Istanbul) and some physicochemical features of the reservoir, were investigated between May 2009 and February 2010. In terms of physicochemical conditions, the trophic state of the reservoir was determined as eutrophic (CTSI= 57.8). A total of 33 rotifera species were identified. Keratella cochlearis represented 40.62% of the total annual rotifera present, and was predominant. It was followed by Polyarthra vulgaris (10.14%), Synchaeta oblonga (9.06%), Brachionus urceolaris (5.58%), Pompholyx sulcata (5.21%) and Epiphanes macroura (%4.86), respectively. The contribution of the other rotifer species to the annual presence of rotifera was determined as being 24.52%. The dominance of these species was attributed to the eutrophic state of the reservoir, because K. cochlearis, P vulgaris, B. urceolaris and P. sulcata are known as eutrophication indicator species, due to their saprobic valences. Also, the trophic state of the reservoir was found to be eutrophic according to the Q(B/T) index (= 3). According to the present data about rotifera species, and the abundance of them, the Buyukcekmece Reservoir was specified as eutrophic. However it is necessary to follow the conditions with periodic monitoring to observe the alterations in the Buyukcekmece Reservoir, in this respect the results of the present study would constitute an important baseline for subsequent studies

Effects of environmental factors on seasonal and spatial changes in surface zooplankton in Golden Horn Estuary (Istanbul, Turkey)

The abundance and spatial distribution of zooplankton at monthly intervals were studied in polluted Golden Horn Estuary (Istanbul, Turkey), from July 2006 to December 2007. Selected water quality parameters also were measured. The zooplankton community was characterized by the presence of freshwater, estuarine and marine species, with a total of 59 taxa. Rotifers were the most important fraction of the total zooplankton, comprising 36.5% of all the samples. The zooplankton exhibited seasonal patterns, with the highest abundance occurring in the summer (979 ind. L_1) and the lowest in the spring (856 ind. L_1). Rotifera was the most abundant group in the upper and middle estuary, whereas Copepoda usually reaches the maximum densities in the higher salinity waters in the lower estuary. The study results indicated that both the sampling time (seasons) and sampling sites jointly had significant effects on the zooplankton densities (MANOVA P &lt; 0.05), and horizontal patterns were related to electrical conductivity, water temperature, dissolved oxygen, suspended particulate matter, pH and chlorophyll a measured in the estuary

A New Rotifer Species for Turkish Inland Waters

The zooplankton fauna of Lake Sapanca (Turkey) was studied during January 2009-May 2010 of monthly intervals. One Rotifera species, Ploesoma truncatum (Levander, 1894) is a new record for the Turkish inland waters fauna