There are over 85 cetacean species in marine and freshwater environments of the world (Bearzi et al., 2008a, b). 20 cetacean species have been recorded in the Mediterranenan (Notarbartolo di Sciara 2002) and 12 species in Turkish waters (Güçlüsoy et al., 2014). Unfortunately the loss of biodiversity and irreparable loss of ecosystem functions as a result of climate change, marine pollution, overfishing at a global level has only been detected in the recent years (Ameer 2008). Intensive and continuously increasing use of Mediterranean and Black Sea basins is causing a negative pressure on the ecosystem (European Commission, 2013). Anthropogenic factors such as bycatch, overfishing, pollution, noise, marine traffic are threatening cetacean species.
First signs and warnings of negative effects of changing environmental condition on organisms can be identified through behavioral data (Caro, 1999). Behavior can help us to understand the relationship of an organism with its environment (Anthony and Blumstein, 2000). Changes in habitat use of an organism and/or a reduction in its population due to the anthropogenic activities are long term results of behavior changes (Caro, 1999; Anthony ve Blumstein, 2000). Though it is necessary to study behavior of an organism to create effective conservation strategies, there is a serious shortage of behavioral studies on wildlife in Turkey.
The majority of cetacean studies in Turkey are focused on species observation/stock records, stranding, by-catch and passive acoustic monitoring. In the beginning of 1900s general properties of dolphins were described along with information on dolphin fisheries (Deveciyan 1926, Tezel 1958, Tezel 1961, Toykarlı 1962, Üner 1971). A study, published in 1988 by Çelikkale on the determination of dolphin stocks in the Black Sea, stands out. Cetacean studies gained speed in 2000s (Öztürk et al 2001a, 2001b; Tonay and Öztürk 2003; Öztürk et al 2004; Dede and Öztürk, 2007; Tonay et al 2008; Dede et al 2009; Öztürk et al 2009a, 2009b; Dede and Tonay 2010; Tonay et al 2012a, 2012b; Dede et al 2013a, 2013b; Tonay and Dede 2013; Öztürk et al 2013). Prof. Dr. Bayram Öztürk pioneered dolphin and whale studies in Turkey.
Cetacean Studies in the Levantine Sea
It’s important to mention that while there are many dedicated surveys on cetacean distribution, abundance and site fidelity on the Western and Central Mediterranean Basin, there is a lack of research effort and data available in the Levantine Sea although some more recent studies have been put forth (Boisseaus et al. 2010, Dede et al. 2009, Francis et al 2003, 2009, Goffman et al. 2010, Panigada et al. 2011, Ryan et al. 2014). The earlier research on the cetacean fauna in the Levantine Sea mostly came from a few stranding reports (Kinzelbach 1986, Marchessaux 1980, Spannier et al. 1981, Wassif 1956).
Greece has carried on continuous cetacean fauna surveys since 1991 in Greek waters, including Crete and Rhodes which is the western border of the Levantine Sea (Carpentieri et al. 1994, Frantzis et al. 2003, Frantzis et al. 2013). These studies mainly focused on the abundance and distribution of cetacean species and individual identifications through photo-ID techniques. According to those previous studies, Hellenic Brench has been chosen as one of the core zone for cetacean diversity in the Mediterranean Sea.
There are few studies covered the Turkish part of the Levantine Sea and all dependent on opportunistic sighting data, stranding data or a single survey. Öztürk and Öztürk (1998) collected the stranding data between 1990-1997, covering the Turkish coast of Aegean and Mediterranean Sea. Dede et al. (2009) carried on a survey between 11-24 July in 2008 in the Turkish coast of Levantine Sea to determine the cetacean fauna. Öztürk et al. (2010) collected opportunistic sighting data, covering the Turkish coast of Aegean and Mediterranean Sea, from fisherman and sailors between 1999 and 2009. Also, Öztürk et al. (2012) reported the sightings of local fisherman between Rhodes and Fethiye in 2010. Öztürk et al. (2013) collected the opportunistic sightings about sperm whales in the Turkish part of the Aegean and Meditteranean Sea between 1994-2012. All of the studies above pointed out the importance of consistent long term studies in the Turkish part of the Levantine Sea. Lastly, Ryan et al 2014 surveyed the whole Levantine Sea for mostly sperm whales and harbour porpoises; it also included the Antalya Bay. According to these previous studies in the Levantine Sea, there are recordings of cetacean species mostly between Cyprus, Antalya Bay and Rhodes. The combined information of previous studies suggests that the area between Cyprus, Antalya and Rhodes has higher cetacean abundance thus proposed as a high seas protected area (Öztürk et al. 2012).
Systematic and exhaustive monitoring of abundance, density and distribution of marine mammals within the Eastern Mediterranean Basin is crucial for the successful creation and management of conservation efforts, as well to insure the compilation of accurate baseline information on these species. This can only be achieved through a continuous study of the area and sharing of information between the different parties, governments, NGOs and general public, this way creating a clearer picture of the Mediterranean cetacean fauna and more successful ways to protect it, thus protecting the entire ecosystem as well.