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Introduction
Ecologically and economically, aquatic ecosystems are important resources and, to this end, a framework for the management and protection of water resources in each main catchment basin across Europe was established in 2000, known as the European Water Framework Directive (WFD; Directive, 2000) (Kaiblinger et al. 2009). Diatoms are a very diverse group of algae (Mann 1999; Wojtal 2009) and good indicators in aquatic ecosystems. They occur in a wide variety of environments and show a broad range of tolerance along several gradients of abiotic factors (Blanco et al. 2008, Alakananda et al. 2011, Rimet 2012, Tornes & Sabater 2015).
Historically, the first freshwater diatom study in Turkey was conducted by Ehrenberg (1844) based on the material collected from the Murat and Aras Rivers. Subsequently, Schröder (1895) collected samples from Anatolia (the Tarsus River in Mersin) and Brunnthaler (1903) investigated diatoms from Lake Iznik. The above studies were followed by the study of Lake Van (the largest lake in Turkey) performed by Legler & Krasske (1940) and Gessner (1957). Numerous phycological studies have since been performed in different catchments in Turkey. These additional studies focused primarily on plankton diatoms, while riverine systems have received less attention. Situated between large continents (Eurasia and Africa), Turkey comprises areas of very diverse geological, climatic and environmental conditions, so we should expect that the diversity of diatoms is high in this region. The aim of this study is to present new sites of rare and new records of diatoms in Turkey from different genera along with morphological characteristics of the species identified.
Materials and methods
Study Area
Kütahya is a border between Inner and Western Anatolia, and Türkmen Mountain is particularly important because it serves as a barrier between the regions. There are three different river catchments in the study area: Sakarya, Susurluk and Gediz. In total, 21 locations were investigated in this study (Figure 1).
Figure 1
Distribution of the investigated localities (Sakarya River Catchment 1 – Türkmen Mountain spring, 2 – Felent Stream, 3 – Porsuk Stream, 4 – Murat Stream, 5 – Kokar Stream, 6 – Ilıca Stream; Susurluk river catchment 7 – Ilıcaksu, 8 – Kocasu Stream, 9 – Emet Stream, 10 – Hisarcık Stream, 11 – Domaniç forest, 12 – Safa Stream, 13 – Muhacırköy district, 14 – Güneyköy district, 15 – Kırık Stream; Gediz river catchment, 16 – Gediz river, 17 – Simav Stream, 18 – Kocaçay Stream, 19 – Naşa district, 20 – Eynal district, 21 – Maden Mountain)
Sampling
Samples were collected at 21 locations. Epilithic samples were collected by brushing submerged stones and epipelic samples were obtained by using a pipette aspirator. The samples were boiled with H2O2 and HCl to remove the organic matter. After repeated washing with distilled water, the material was air-dried on cover glasses and mounted in Naphrax. Observations of the diatoms were performed partly at Szczecin University and Dumlupınar University. The micrographs were taken with a Nikon DS-Fi1 camera.
Dimensions. Valve 9.72-16.16 μm in diameter and 12-20 striae in 10 μm.
Distribution in Kütahya running waters. Kokar Stream (Sakarya river catchment) and Gediz Stream (Gediz river catchment).
Distribution in Turkey. Previously found at a few sites in Western Anatolia (Sakarya river catchmentAcarlar forest– Tunca et al. 2014, Poyrazlar reservoir – Olgun-Sevindik et al. 2015), Northern Anatolia (Yeşilırmak river catchment-Simenit Lake – Ersanlı & Gönülol 2006), Eastern Anatolia (Fırat river catchment-Köprüköy – Altuner & Pabuçcu 1993, 1994, Aras-Demirdöven Reservoir – Kıvrak & Gürbüz 2005 and Tortum Lake – Altuner 1984).
Lindavia balatonis (Pantocsek) T. Nakov et al. Fig. 2: 6, 7
Dimensions. Valve 11.70-11.87 μm length and 3.25-4.18 μm breadth.
Distribution in Kütahya running waters. Spring in Türkmen Mountain (Sakarya river catchment), Sefa Streams (Susurluk river catchment) and Kocaçay (Gediz river catchment).
Dimensions. Valve 26.82-43.54 μm length and 2.18-2.34 μm breadth, 17-19 striae in 10 μm.
Distribution in Kütahya running waters. Spring in Türkmen Mountain (Sakarya river catchment) and Muhacırköy district (Susurluk river catchment).
Distribution in Turkey. Previous record of this taxon is from Eastern Anatolia (Çoruh river catchment-Tortum Waterfall-Kıvrak & Gürbüz 2006), Inner Anatollia (Konya closed basin-Melendiz Stream – Sıvacı & Dere 2007) and Southern Anatolia (Burdur river catchmentDarıören & Isparta Streams – Çiçek et al. 2010).
Dimensions. Valve 11.22-24.41 μm length and 3.84-5.57 μm breadth, 14-17 striae in 10 μm.
Distribution in Kütahya running waters. Safa Stream (Susurluk river catchment), Murat Stream (Sakarya river catchment), Simav Stream (Gediz river catchment).
Distribution in Turkey. It was found only in Inner Anatolia (Konya-closed basin-Beyşehir Lake – Cirik et al. 1991).
Dimensions. Valve 54.69-68.02 μm length and 11.07-12.66 breadth, 7-8 striae in 10 μm.
Distribution in Kütahya running waters. Murat Stream (Sakarya river catchment) and Naşa district (Gediz river catchment).
Distribution in Turkey. It was found only in Inner Anatolia (Kızılırmak river catchment-Karagöl Lake – Açıkgöz & Baykal 2005), Southern Anatolia (Antalya river catchment-Darıören and Isparta Streams – Çiçek et al. 2010).
Dimensions. Valve 59.1-69.60 μm length and 8.93-10.06 μm breadth, 7-11 striae in 10 μm.
Distribution in Kütahya running waters. Murat Stream (Sakarya river catchment) and Kocasu Stream (Susurluk river catchment).
Distribution in Turkey. This species was previously found only in Blacksea (Eastern Blacksea river cathment-Uzungöl Lake – Şahin 1998) and Western Anatolia (Büyük Menderes river catchment-Akçay Stream-Solak et al. 2005 and Sakarya river catchmentPorsuk River – Yıldız 1987).
Dimensions. Valve 17.30-19.74 μm length and 5.70-5.92 μm breadth, 14-15 striae in 10 μm.
Distribution in Kütahya running waters. Hisarcık Stream (Gediz river catchment) and Kocaçay Stream (Gediz river catchment).
Distribution in Turkey. This taxon was previously found only in Inner Anatolia (Konya closed basin-Hotamış Marshes – Yıldız et al. 1998, Hirfanlı reservoir – Baykal & Açıkgöz 2004 & Çamlıdere reservoir – Baykal 2006) and Blacksea (Eastern Blacksea river catchment-Uzungöl Lake – Şahin 1998).
Humidophila contenta (Grunow) Lowe, Kociołek, Johansen, Van de Vijver, Lange-Bertalot & Kopalová Fig. 4: 75-77
Dimensions. Valve 11.98-19.93 μm length and 4.52-6.52 μm breadth, 18-22 striae in 10 μm.
Distribution in Kütahya running waters. Spring in Türkmen Mountain (Sakarya river catchment).
Distribution in Turkey. Previous records indicate this taxon was found only in Western Anatolia (Sakarya river catchment-Türkmen Mountain – Levkov et al. 2013).
Dimensions. Valve 6.05-19.21 μm length and 4.13-6.51 μm breadth, 18-22 striae in 10 μm.
Distribution in Kütahya running waters. Spring in Türkmen Mountain (Sakarya river catchment).
Distribution in Turkey. This endemic species was previously found in Turkey in Western Anatolia (Sakarya river catchment-Türkmen Mountain – Levkov et al. 2013).
Dimensions. Valve 20.82-26.51 μm length and 6.58-7.42 μm breadth, 21-24 striae in 10 μm.
Distribution in Kütahya running waters. Kırık Stream and Ilıcaksu (Susurluk river catchment).
Distribution in Turkey. Previously found only in Inner Anatolia (Kızılırmak river catchment-Hirfanlı Reservoir – Baykal & Açıkgöz 2004) and Northern Anatolia (Yeşilırmak river catchment-Ladik Lake – Maraşlıoğlu et al. 2005).
Dimensions. Valve 30.56-54.58 μm length and 2.38- 3.15 μm breadth, 18-21 fibulae in 10 μm.
Distribution in Kütahya running waters. Murat Stream (Sakarya river catchment), Kocaçay Stream, Simav Stream, Eynal district (Gediz river catchment).
Distribution in Turkey. Previously found only in Inner Anatolia (Kızılırmak river catchment-Çanıllı reservoir – Atıcı et al. 2008 and Asartepe reservoir – Atıcı & Obalı 2010).
Dimensions. Valve 58.05-82.85 μm length and 12.07-14.31 μm breadth, 9-11 striae in 10 μm.
Distribution in Kütahya running waters. Spring in Türkmen Mountain (Sakarya river catchment).
Distribution in Turkey. Previously found only in Northern Anatolia (Eastern Blacksea- Uzungöl Lake-Şahin 1998) and Inner Anatolia (Kızılırmak river catchment-Kuzgun Reservoir – Gürbüz & Kıvrak 2003).
Dimensions. Valve 18.78-21.54 μm length and 7.21-10.17 μm breadth, 21-27 striae in 10 μm.
Distribution in Kütahya running waters. Spring in Türkmen Mountain (Sakarya river catchment).
Distribution in Turkey. Previously known only from Inner Anatolia (Kızılırmak river catchment-Hirfanlı Reservoir – Baykal & Açıkgöz 2004) and Northern Anatolia (Sakarya river catchment-Melen River – Baykal et al. 2011).
Sellaphora radiosa (Hustedt) H. Kobayasi Fig. 6: 142, 143
Dimensions. Valve 6.71-18.73 μm length and 3.21-4.82 μm breadth, 19-24 striae in 10 μm.
Distribution in Kütahya running waters. Spring in Türkmen Mountain (Sakarya river catchment) and some springs in Domaniç forest (Susurluk river catchment).
Distribution in Turkey. Previously found only in Northern Anatolia (Sakarya river catchment-Acarlar forest – Tunca et al. 2014).
Sellaphora seminulum (Grunow) D. G. Mann Fig. 6: 144, 145
Dimensions. Valve 5.21-16.34 μm length and 3.12-4.42 μm breadth, 10-22 striae in 10 μm.
Distribution in Kütahya running waters. Spring in Türkmen Mountain (Sakarya river catchment) and some springs in Domaniç forest (Susurluk river catchment).
Distribution in Turkey. Previously known only from Inner Anatolia (Kızılırmak river catchment-Hirfanlı
Dimensions. Valve 6.82-19.94 μm length and 3.45-4.52 μm breadth, 16-30 striae in 10 μm.
Distribution in Kütahya running waters. Spring in Türkmen Mountain (Sakarya river catchment).
Distribution in Turkey. NEW RECORD.
Discussion
Of the study sites on which this work is based, the Sakarya River catchment is one of the most extensively studied areas, while only a few previous studies have addressed Gediz and Susurluk River catchments (detailed inSolak et al. 2012). Among the study sites, the Sakarya River catchment is especially important since many of the new records (50 species, 68.5%) were noted from Türkmen Mountain and the Murat River. Türkmen Mountain is located between two different climatic zones; the Aegean region has cool, rainy winters and hot, moderately dry summers, while Inner Anatolia experiences extremes of hot summers and cold winters with reduced rainfall (Ünal et al. 2003). Most of the identified species from this area would be considered indicators of eutrophic conditions, while several species identified from Türkmen Mountain, including the Kocaçay Stream and the Kırık Stream, would be classified as characteristic of oligotrophic conditions (e.g. Cymbella subleptoceros, Fallacia insociabilis, Navicula kotschyi, Nittzschia brunoi, Pinnularia nodosa and Sellaphora stroemii).
In total, more than 800 diatom taxa have been found in Turkish lentic and lotic systems to date. However, many of the diatoms commonly reported from very diverse water bodies in Turkey are taxa known from European and Asiatic areas (Solak & Wojtal 2012). The number of diatoms has been estimated to include approximately 100,000 species in over 1,000 genera (Mann 1999, Fourtanier and Kociołek 1999, 2003). The diversity of diatoms in Turkey is relatively low compared to the total number worldwide. The number of species in Turkey is also low compared to other countries, such as Korea (Park et al. 2014). Some species probably have been confused with morphologically similar taxa. For example, Cymbella affinis Kützing is one of the most common species in the Turkish flora. However, the species was split into several new species by Krammer (2002), similarly to what was done with the C. cistula group. Navicula cryptotenella Lange-Bertalot is also very common in Turkey and N. cryptotenelloides Lange-Bertalot (reported here as a new record for Turkey) is morphologically very similar to N. crytotenella (valve breadth and striation are important to distinguish between the two taxa). The tendency to use older taxonomy that recognizes fewer species is one of the reasons the freshwater diatom flora of Turkey may apparently seem to have a reduced number of species.
The fact that some species occur only in specific environments could be another reason why the freshwater diatom flora of Turkey may appear poorer in species than it might be expected. For example, Pinnularia nodosa is common only in Türkmen Mountain springs. Many of these unique environments in Turkey have not been researched yet. It is extremely important to pay constant attention via continuous monitoring of diverse areas to understand the diversity of diatoms in Turkey. In this regard, the Murat Stream was an important sampling site. This system has brought some new records and rare species in this study. A detailed investigation of this system may reveal additional interesting taxa for the flora of Turkey.
