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Marine Turtle Newsletter 131:7-9, © 2011

Marine Turtle Newsletter-Online

Nesting Characteristics at Samandağ and Extended Beaches, Turkey

Şükran Yalçın-Özdilek1 & Bektaş Sönmez2
1Çanakkale Onsekiz Mart University, Science and Letters Faculty, Biology Department, Division of Ecology 17100 Canakkale Turkey (E-mail: syalcinozdilek@gmail.com);
2Çanakkale Onsekiz Mart University Sea Turtle Research and Application Centre, Samandağ Governor Scientific Research Centre Samandağ Hatay Turkey (E-mail: bektass@gmail.com)

Two endangered marine turtle species, loggerheads (Caretta caretta) and greens (Chelonia mydas), nest regularly in the Mediterranean (Casale & Margaritoulis 2010). The beach of Samandağ in Turkey is one of the most important nesting grounds for green turtles in the Mediterranean (Kasparek et. al 2001; Broderick et al. 2002; Canbolat 2004), and is also used by loggerhead turtles for nesting. Green and loggerhead turtles also nest along additional stretches of beach near Samandağ. Existing literature has indicated that dramatic fluctuations in green turtle nesting numbers may arise in response to inter-annual variations in weather conditions (Limpus & Nicholas 1987; Broderick et. al. 2001), which may cause bias in calculations of population density (Demetropoulus & Hadjichristophorou 1995; Limpus 1996). For this reason, continuous long-term annual monitoring programs have been proposed by conservation organizations to obtain reliable data about sea turtles (Kasparek et al. 2001). At Samandağ beach, previous studies have been conducted intermittently across short monitoring periods (Yerli & Demirayak 1996; Yerli & Canbolat 1998; Yalçın 2003). There are a few studies about nesting activity of sea turtles at the additional sites near Samandağ (Yalçın-Özdilek & Sönmez 2006). A continuous conservation program was started at Samandağ Beach in 2001 and at the additional sites from 2005 onwards. Here we provide reliable data about sea turtle nesting numbers at Samandağ beach and at the additional sites (Çevlik-Kale).


Figure 1. Samandağ (Meydan, Şeyhhızır and Çevlik beaches) and the extended beaches (Tr- H-1, Tr-H-2, Tr-H-3 and Kale beaches).

Samandağ beach is bordered by Çevlik harbour to the North and Cape Sabca to the South (Fig. 1). The beach has been divided into three sections; Çevlik beach (approximately 5.5 km long), Şeyhhızır beach (approximately 4.1 km long), and Meydan beach (approximately 4.4 km long). The Asi river passes between Seyhhızır and Meydan beaches. The coastline between Çevlik and Kale, which is termed here as the extension of Samandağ beach, is about 26 km in length (Fig. 1), along which there are five additional small beaches: TRH-1, TRH-2, TRH-3, Kale1, and Kale2. Beach monitoring data were collected during 10 years for Samandağ beach and six years for the extended beaches, following the methodology described in Yalçın-Özdilek & Sonmez (2006) and Yalçın-Özdilek (2007).

Total nesting and non-nesting emergences for both species were recorded and assessed by beach sections for the Samandağ area and for the five additional nesting beaches combined and grouped together as the ‘extended beaches’ (Çevlik-Kale area). Furthermore, we calculated nest density (nest number per km) specifically for Samandağ and Kale beach.

Green turtles: Between 2001-2010, 7014 green turtle emergences were recorded at Samandağ Beach (mean= 701.4 ± 590.6 SD, range= 52-1825;). Of these emergences, 2411 were nests, ranging from 16 to 621 per year (mean = 241.1 ± 208.1 SD). When considering Samandağ beach by section, the Şeyhhızır sector had the most nests during the 10 year period (mean = 190 ±164 SD, range =14-468;), followed by the Meydan sector (mean = 40 ±29 SD, range = 2-83), and lastly the Çevlik sector (mean =19 ± 22 SD, range = 1-70). Nest density ranged from 1.1 to 44.3 nests per km for the monitored years (mean = 17.5 ± 14.5 SD; Fig. 2). Şeyhhızır was the most densely nested sector during the 10 year period (mean 46.3 ± 39.9 SD, range = 3.4-114.1), followed by the Meydan sector (mean 8.2 ± 6.8 SD, range = 0-18.9), and lastly the Çevlik sector (mean = 2.7 ± 3.8, range 0-12.7). Human pressure is greatest at the Çevlik sector, followed by Meydan and Şeyhhızır, respectively. At the Şeyhhızır and Meydan sectors, nests were primarily concentrated along a 3 km stretch on either side of the north and south parts of the Asi River, which is the least disturbed area of all Samandağ Beach. In general, the majority of nests were laid in July (10 year mean: 59% ± 12.2 SD, range = 45-85%), except for in 2008 and 2009 when the majority of nests were laid in June (2008 = 52% nests, 2009 = 53% nests).


Figure 2. Annual green turtle nesting densities along the three sectors of Samandağ Beach: Cevlik (white bars), Şeyhhızır (grey bars), and Meydan (black bars).

Loggerhead turtles: Along the 14 km stretch of Samandağ beach, 205 loggerhead turtle emergences were recorded across the 10 year monitoring period. Of these emergences, 87 were nests, ranging from 0 to 20 per year (mean = 10 ± 5.6 SD). Of interest, in 2001 only three non-nesting emergences were observed, and no loggerhead emergences were seen in 2008 (Fig. 3). In 2001, a conservation plan was not in place; hence, illegal sand extraction may have contributed to the low number of green turtles being recorded, and the absence of loggerhead turtles. However, additional human impact was not observed in the 2008 season at Samandağ Beach.


Figure 3. Annual number of loggerhead nests (dark grey bars) and total number of emergences (light grey bars) for loggerhead turtles along the Samandağ Beach.

Loggerhead nesting density ranged from 0 to 1.4 nests per km across the 10 year period (mean = 0.7 ± 0.4 SD). When loggerhead turtle nest numbers were classified per section of Samandağ beach, Şeyhhızır had the highest number and density of nests (mean number = 5 ± 4 SD, mean density = 1.2 ± 1 SD), followed by Çevlik (mean number = 3.1± 4.4 SD; mean density = 0.6 ± 0.8 SD) and Meydan (mean number = 0.6 ± 1 SD; mean density= 0.1 ± 0.2 SD).

The majority of nests were laid in July (10 year mean = 57.1% ± 27.7 SD, range = 0-83.3), except for in 2003, 2006, 2007 and 2009 when the majority of nests were laid in June (2003 = 63.6% nests; 2006 = 55.6%; 2007 = 50%; 2009 = 60%).


Figure 4. Annual number of green turtle nests (dark grey bars) and emergences (light grey bars) along the five beach sectors distributed between Çevlik and Kale.

Extended Beach (Çevlik-Kale Beaches): Along the five beach sectors distributed between Çevlik and Kale, 126 green turtle emergences were recorded across a six year monitoring period (2005-2010). Of these emergences, 47 were nests (mean = 7.8 ± 8.3 SD, range = 0-23). Of interest, no green turtle emergences were recorded in the 2010 (Fig. 4). In total, 422 loggerhead turtle emergences were recorded across the six year monitoring period. Of these emergences, 93 were nests (annual mean = 15.5 ± 7.7 SD, range 5-25, Fig. 5). The majority of nests and emergences were recorded at Kale Beach, which is about 1.5 km in length. The nest density per km of loggerhead turtle at this beach was mean = 10.3 ± 5.1 SD, range = 3.3-16.7, indicating its importance for loggerhead nesting in the Eastern Mediterranean. The loggerhead nest density is highest on the western part of Turkey and decreases toward to eastern beaches. The observed nest density of Kale section is higher than that of the adjacent beaches in the eastern part of the Turkey (Canbolat 2004). There is no direct human access to the Kale section due to its distance from villages in the region; hence it is a favourable nesting site for loggerhead turtles.


Figure 5. Annual number of loggerhead turtle nests (dark grey bars) and emergences (light grey bars) the five beach sectors distributed between Çevlik and Kale.

The results of this long term study indicate that mean annual nest numbers in Samandağ and extended sections are higher than indicated in previous studies based on short term monitoring (Yalçın-Özdilek & Sönmez, 2006, Yalçın-Özdilek 2007). Therefore, this area represents one of the most important nesting areas for sea turtles, and a long-term conservation plan should be implemented in this area.

A number of anthropogenic problems threatening sea turtle nesting effort exist at Samandağ Beach. These have been reported in scientific, governmental and public sector literature (Yerli & Demirayak 1996; Yerli & Canbolat 1998; Yalçın 2003; Yalçın- Özdilek & Sönmez 2003; Yalçın-Özdilek & Yerli 2006). In brief, they include illegal sand extraction, litter, flooding and tourism activities. In addition, coastal erosion, which occurs as a consequence of human activities, contributes indirectly and is the main problem in nesting areas.

A conservation plan has been implemented at Samandağ beach for the past 10 years and at the extended beach area for the last six years. The conservation plan principally outlines actions for identifying short term problems and their solutions, and developing long term solutions. The regular daily monitoring of sea turtles during the nesting and hatchling seasons serves as a deterrent for illegal sand extraction. In order to improve public awareness, regular and continuous training activities were performed for children, adults, tourists and also fishermen. Unfortunately, even at reduced levels, anthropogenic problems continue to occur, in addition to natural problems such as predation by ghost crabs, foxes and dogs on the nesting beaches. Furthermore, attempts to install wind energy plants near the beaches are in progress. In parallel, facilities for developing tourism activities continue in this region, particularly in the most popular beach sector, with Şeyhhızır and Kale possibly facing increased pressure from tourism in the near future. 
The management plan is dependent on the collaboration among governmental, non-governmental and academic organizations, who supply student volunteers to conduct the monitoring work. The daily monitoring program during the nesting season should continue to operate until local inhabitants undertake conservation responsibilities. Particularly, the conservation plan suggests an increase in the contribution of local NGOs to conservation actions in future, and also strongly recommends national and international collaborations for the sustainable development of tourism activities and installation of energy resources in a sustainable manner in Samandağ and extended beach areas.

Acknowledgements: The long term study at Samandağ was implemented with the assistance of the Samandağ Governor, Hatay Directorate of Environmental Ministry and Natural Parks and Nature Protect Division. We are thankful to all these organizations. We also thank Sait Gürsoy and K. Mehmet Ali Sönmez and many other student volunteers for their assistance on the field. We also thank the reviewers for their valuable contributions.

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