Ayhan Dede Ph.D. & Arda M. Tonay Ph.D.

78 cetaceans exist around the world seas and freshwaters. Cetacea ordo is divided into 2 different suborda that are; Odontoceti and Misticeti. Even though it can create some conflicts, if the cetacean is bigger than 4 m, we name them whale and if it’s smaller, we name them dolphins. They spend all of their life stages in the water.

There are 21 different Cetacea species in the Mediterranean, including the Black Sea. 10 of them live in Turkish waters (Table 1). Another marine mammal endangered in the Mediterranean and Aegean Seas is the Monk Seal, Monachus monachus.

Table 1. Marine Mammals in Turkey

Mysticeti

Balaenoptera physalus (Fin whale)

Odontoceti

Physeter catodon (Sperm whale)

Ziphius cavirostris (Cuvier’s beaked whale)

Globicephala melas (Long finned whale)

Pseudorca crassidens (False killer whale)

Grampus griseus (Grampus)

Tursiops truncatus (Bottlenose dolphin)

Stenella coeruleoalba (Striped dolphin)

Delphinus delphis (Common dolphin)

Phocoena phocoena (Harbour porpoise)

Pinnipedia

Monachus monachus (Mediterranean Monk Seal)

In Turkey, since 1983, marine mammal hunting has been prohibited and they are under protection by law.

Harbour Porpoise (Phocoena phocoena)

They live only in the cool waters of the northern hemisphere and subpolar regions. They are mostly found on the shores and coastal regions. The Harbor Porpoise is a little smaller than the other porpoises. It is about 70-90 cm long at birth. Both sexes grow up to be 1.4 m to 1.8 m. They weight 40-86 kg. They only live in the Black Sea in Mediterranean Basin and they are the smallest cetacean member. There are observations on North Aegean, Marmara. They forage both on benthic and pelagic fishes. Their group size is mostly less than 8 individuals but they can form a group of 50 to a hundred or more individuals during migration or foraging. Normally, they don’t jump out of the water. Bycatch also occurs for this species. They are distributed around the Black Sea coasts of Turkey. There is a sharp decline in the population numbers during the hunting season of turbot (April, May, June).

Bottlenose Dolphin (Tursiops truncatus)

They are wide-ranged, cosmopolite species distributed along the coast and inland sea. They can be observed all around the Mediterranean, especially near the shore and sometimes in the open sea. They have an obvious melon, short beak and a high dorsal fin. Their body color is mostly grayish white and the ventral part is brighter. They mostly feed with fishes like anchovy and blue fin. Their adults are 1,9-3,8 m in size and weigh 650 kg. Their pregnancy takes 11 months. Their group size is usually less than 20 but can be hundreds. It is reported that they race with sea vessels. They sometimes damage fishing nets when they hunt but they are sometimes drowned because of the nets in the Black Sea.

Common Dolphin (Delphinus delphis)

They live in tropical and warm oceans. Their rostrum is thin and long. Their dorsal fin is shaped like a hook and its middle part has a brighter color. The color of their dorsal area is grey and blackish, while their ventral area is white. The newborns are 80-85 cm in size and adult females can reach 2,3 m in size while the males can reach 2,6 m. They weight 135 kg. They are fast swimmers. Common dolphins travel in groups of approximately 10-50 individuals and frequently gather into schools of 100 to 2000 individuals. They can be found in all the seas of Turkey.

Striped Dolphin (Stenella coeruleoalba)

The Striped Dolphin likes temperate or tropical offshore waters and is a cosmopolite species. They come close to the shore where deep seas are near the coast. Their rostrum is long and their dorsal fin shapes like a hook. There are one or two black bands that circle the eye and run across the back, to the flipper. These bands widen to the width of the flipper. There are two further black stripes running from behind the ear: a short one that ends just above the flipper and a longer one that thickens along the flanks until it curves down under the belly just prior to the tailstock. Above these stripes, the dolphin’s flanks are colored light blue or grey. All the appendages are black. By adulthood, they have grown to 2.6 m and weigh 150 kg. Gestation lasts approximately 11 months. They are fast swimmers and jump out of the water frequently. They are distributed in the Aegean and Mediterranean coasts. They are known to drown from tangling in the swordfish nets.

Grampus (Grampus griseus)

They live in both hemispheres. They prefer temperate and tropical pelagic waters. They form small groups and may follow other species of dolphins. Juvenile color is bright grey or brownish grey, however, adult color is dark grey to white. It is observed that adults have scars and dots on their bodies. Their frontal fins are long and dotted. At birth, their size is 1,2-1,5 m, while adults reach 3-4 m and weigh 400 kg. They are pelagic. They are distributed in the Aegean and Mediterranean Seas of Turkey. They can get bycaught during swordfish hunting.

Pilot Whale (Globicephala melas)

They are distributed in the temperate and subpolar regions. Their body color is black and dark grey. Their pectoral fin is flat and long. Newborns are 1,7-1,8 m in length, while adult males reach 6,7 m and females reach 5,7m. Adults can weigh 2 tons. They usually form groups of 20-100 individuals. They can be observed in the Aegean and Mediterranean coasts.

Cuvier’s Beaked Whale (Ziphius cavirostris)

They live in the pelagic regions and mostly prefer temperate and tropical offshore regions. They are widely distributed all around the Mediterranean. They prefer depths like 1000m or more. They have a rough and long body. The front part turns white in the adults. Their group size is mostly 2 to 7 individuals and they can dive for 40 min. At birth, they are 2,7 m and adult females reach 7 m while males can reach 7,5 m. They can weigh 3 tons. They have been observed on the Mediterranean coast of Turkey.

False Killer Whale (Pseudorca crassidens)

They mostly live in tropical and temperate waters and prefer offshore areas. Their color is dark grey-black and the ventral part is grey-white. There are brighter parts on the front and ventral. Their group is formed of 10 to 50 individuals. Mass mortality is frequently observed in this species. At birth, their length is 1,5-2,1 m. and adult males reach 5,5-6 m whereas females reach 4,5-5 m in size. One individual of this species was found wounded and died a while later in Urla in 1994. They are rarely present in the Aegean and Mediterranean coasts of Turkey.

Sperm Whale (Physeter catodon)

Sperm whales are a cosmopolite species in the world’s seas and oceans. They can dive to 1500m in depth. They live offshore, in deep waters and can be observed close to the coastal areas if deep sea is present. They form groups of 2-50 individuals. They can stay underwater for 1-2 hours. They are the biggest species in Odontoceti. Their body color is mostly black and grey-brownish, and the ventral part is white. They have a big angular head and one blowing hole. Mostly, prior to their long dive, their tail goes up. Newborns can be 3,5-4,5 m in length and adult males reach 18-20 m., whereas females reach 12 m. They weigh 30-50 tons. They are observed in the Aegean and Mediterranean coasts of Turkey. In 2002, a female sperm whale was bycaught from the mouth and rescued by divers of navy forces and fishermen in Ölüdeniz.

Fin Whale (Balaenoptera physalus)

Members of this species show cosmopolite behavior and are frequently observed in the central and west Mediterranean. They mostly live in open seas. They can be solitary or form groups of 6 to 10 individuals. Their dorsal part is black and dark brown and ventral part is brighter in color. They have 260-480 plates in the maxilla. They are the biggest whales of the Mediterranean. Newborns are 6-6,5 meters in length. Adult length is 18-27 m and can weigh 45-75 tons. They are observed on the Aegean and Mediterranean coasts of Turkey. In 2000, a juvenile fin whale was stranded and died in Adana, Yumurtalık, and was buried for a year. After a year, its skeleton was taken out and prepared for educational exhibitions.

Mediterranean Monk Seal (Monachus monachus)

They are one of the most endangered species and currently can be observed in Madeira island and Mediterranean, mostly in Turkey and Greece. They prefer rocky shores and islands, as well as isolated caves. They come on land for sleeping and resting. They hunt in the coastal region up to 30 m depth. Their deepest dive is 75 m. At birth, they are 80-120 cm and weigh 15-26 kg. Adults can reach 2,8-3,1 m in length and weigh 250-400 kg. They can form groups of 5-6 individuals or form colonies along wide beaches. Members of this species are frequently observed as isolated and solitary in the Mediterranean. They feed on various types of fish, crustacean and cephalopods. It is estimated that there are only 50-100 individuals left on the Aegean and Mediterranean coasts of Turkey. In recent years, it can no longer be observed in the Black Sea and the Marmara Sea.

Marine mammals are at the top of the food pyramid and they can only give birth once every two years. They are under threat for many reasons. All of those threats originate from anthropogenic factors like bycatch, water and noise pollution, drifting wastes, overfishing and intentional killing. In the Mediterranean region, common dolphins, striped dolphins and Grampus get bycaught in the swordfish nets. Moreover, in the Black sea, harbor porpoises, common dolphins and bottlenose dolphins get bycaught due to turbot fishing. Unfortunately, mass mortalities, as well as the frequency of diseases increase due to pollution and decreasing amounts of prey. All of the Odontocete and some of the Mystacoceti whales use echolocation to find their food so the effect of noise pollution on them is vital.

We are neither aware of our seas nor are we interested in them. Common dolphins are classified as endangered by IUCN since 2003. It’s assumed that the total population of Monk Seals is less than 250 adults, and they are critically endangered.

Since 1993, by the leadership of Prof.Dr. Bayram Öztürk, our team conducts scientific studies on marine mammals. Our studies are mostly focused on fisherman interaction, stranding, population distribution and size, migration path in Istanbul Strait, photo-id, genetic structure, skull collection, stomach content, conservation strategies and etc.

Please, inform us about the cetacean observations you did. All of these notifications are important for our scientific studies.

References:

Jefferson, A.T., Leatherwood, S., Webber, M.A. 1993. Marine Mammals of the World. FAO Species Identification Guide. UNEP/FAO. Rome

Öztürk, B. 1992. Akdeniz Foku. Anahtar Yayınevi, İstanbul. (in Turkish)

Öztürk B. 1996. Balinalar ve Yunuslar Setolojiye Giriş. Anahtar Yayınları. İstanbul.(in Turkish)

Öztürk, B., Topaloğlu, B., Dede, A., 2003, Deniz Canlıları Rehberi. TUDAV Eğitim Serisi No: 6. 181s.İstanbul. (in Turkish)

Öztürk B., Dede A. (1995) Present status of the Mediterranean monk seal, Monachus monachus (Hermann, 1779) on the coast of Foça in the bay of İzmir (Aegean Sea). Turkish Journal of Marine Sciences 1(2/3):95-107

Dede, A. 1998. Investigation on the Mediterranean Monk Seal (Monachus monachus Herman, 1779) in Gökçeada (Northern Aegean Sea). 35 th C.I.E.S.M XXXV. Congress 1-5 June 1998, Vol. 35 (2) Dubrovnik (Crotia) p 534

Öztürk, B., Öztürk, A. A., Dede, A. 2001. Dolphin by-catch in the swordfish driftnet fishery in the Aegean Sea. 36th CIESM Congress Proceedings, Monte Carlo, Vol 36, p 308.

Tonay A.M.& Öztürk B. 2003. Cetacean Bycatches in Turbot Fishery on the Western Coast of the Turkish Black Sea. In: Oray, I.K., Çelikkale, M.S., Özdemir, G. (Eds.), International Symposium of Fisheries and Zoology (In memory of Ord. Prof. Dr. Curt KOSSWIG in His 100th Birth Anniversary), İstanbul. 131-138pp.