CARTILAGINOUS FISH (SHARKS AND RAYS) RESEARCH AND CONSERVATION PROGRAMME IN TURKEY BY TURKISH MARINE RESEARCH FOUNDATION

INTRODUCTION

Turkish Marine Research Foundation (TUDAV) has been engaged in research, educational seminars and conservation efforts to protect biodiversity in marine environments since its establishment. Cartilaginous fish consisting of rays, sharks and chimaeras are endangered around the world. They’ve been becoming the focus of attention in terms of biodiversity and conservation due to their slow growth and low fecundity, gathering public attention due to their decreasing numbers caused by incidental bycatch, overfishing, pollution and habitat loss. Multiple organizations such as IUCN, SPA/RAC and GFCM have conservation action plans for cartilaginous fish.

Most people, under false impressions arising from the movie ‘Jaws’, are intimated and repulsed by sharks, not helped in the least by their often misleading names. The reality is different; they have been a valuable part of marine ecosystems for millions of years.

Our foundation has organized an international conference on cartilaginous fish in 2005 and published the proceedings as a book in order to raise awareness of the issue.

Historical workshop proceedings and some of the participants

The workshop was followed up with national meeting held on 10-11 March 2017, gathering experts and beginning the work on a national action plan to be published.

National Workshop for the Action Plan of Cartilaginous Fish Conservation

12 species have been placed under protection as the result of a ministry appeal by TUDAV in 2018. This included several species of rays, gaining protection for the first time.

Our foundation has been keeping track of the protected species of rays and sharks, and we have taken appropriate actions against the offending parties by applying to the relevant authority – CIMER (Republic of Turkey, Directorate of Communications).

 

Sharks and rays are long-lived, slow-growing marine animals possessing a cartilaginous skeleton. Found all over the world from coral reefs to deep seas, they can be anywhere from less than 1 meter to more than 10 meters in length. Sharks have 6 senses: smell, taste, sight, hearing, touch and electromagnetism. Their sight has evolved based on their environment and their prey. They have a very well developed sense of smell but taste is not their strong point. They can sense muscle contractions from nearby animals thanks to their sense of electromagnetism. Mostly ovoviviparous and occasionally viviparous, they are live-bearing marine animals with low fecundity – some species do, however, lay a few eggs.  (Smithsonian, 2018).

Egg cases of a few sharks and rays are below. Please send us photographs if you find these eggs as they are important indicators of the presence of these species in surrounding waters.

Shark and ray egg capsules

Shark and ray teeth can be used to identify the species. Having sharp teeth makes them easy targets for fisheries.

Teeth of some shark (left) and ray (right) species

Some shark and ray teeth are sold as souvenirs.

Some sharks are served as food on our tables.

Shark meat in a supermarket

Sandbar shark (Carcharias plumbeus) comes to Boncuk Cove in Gokova Bay every year to reproduce.

Sandbar shark, Gokova Bay, Boncuk Cove

Occasional shark attacks do happen around the world but the likelihood of it happening is extremely small.

SPECIES

77 species of cartilaginous fish are found in the Mediterranean: 43 species of sharks, 33 species of rays and a single species of chimaera. Carcharhinus brevipinna, Himantura uarnak, Sphyrna mokarran and Sphyrna lewini are not endemic to the region. 57 species can be observed at the Aegean Sea (IUCN, 2016).

CARCHARHINIDAE (REQUIEM SHARKS)
Carcharhinus altimus
Carcharhinus brachyurus
Carcharhinus brevipinna
Carcharhinus limbatus
Carcharhinus obscurus
Carcharhinus plumbeus
Prionace glauca

SCYLIORHINIDAE (CATSHARKS)
Galeus atlanticus
Galeus melastomus
Scyliorhinus canicula
Scyliorhinus stellaris 

SPHYRNIDAE (HAMMERHEAD SHARKS)
Sphyrna lewini
Sphyrna mokarran
Sphyrna zygaena

TRIAKIDAE (HOUNDSHARKS)
Galeorhinus galeus
Mustelus asterias
Mustelus mustelus
Mustelus punctulatus

HEXANCHIDAE (COWSHARKS)
Heptranchias perlo
Hexanchus griseus
Hexanchus nakamurai

ALOPIIDAE (THRESHER SHARKS)
Alopias superciliosus
Alopias vulpinus

CETORHINIDAE (BASKING SHARKS)
Cetorhinus maximus

LAMNIDAE (MACKEREL SHARKS)
Carcharodon carcharias
Isurus oxyrinchus
Isurus paucus
Lamna nasus

ODONTASPIDIDAE (SAND TIGER SHARKS)
Carcharias taurus
Odontaspis ferox

CENTROPHORIDAE (GULPER SHARKS)
Centrophorus granulosus

DALATIIDAE (KITEFIN SHARKS)
Dalatias licha

ECHINORHINIDAE (BRAMBLE SHARKS)
Echinorhinus brucus

ETMOPTERIDAE (LANTERN SHARKS)
Etmopterus spinax

OXYNOTIDAE (ROUGH SHARKS)
Oxynotus centrina

SOMNIOSIDAE (SLEEPER SHARKS)
Centroscymnus coelolepis
Somniosus rostratus

SQUALIDAE (DOGFISH SHARKS)
Squalus acanthias
Squalus blainville
Squalus megalops

SQUATINIDAE (ANGEL SHARKS)
Squatina aculeata
Squatina oculata
Squatina squatina

DASYATIDAE (STINGRAYS)
Dasyatis centroura
Dasyatis marmorata
Dasyatis pastinaca
Himantura uarnak
Pteroplatytrygon violacea
Taeniurops grabata

GYMNURIDAE (BUTTERFLY RAYS)
Gymnura altavela

MOBULIDAE (DEVIL RAYS, MANTAS)
Mobula mobular

MYLIOBATIDAE (EAGLE RAYS)
Myliobatis aquila
Pteromylaeus bovinus

PRISTIDAE (SAWFISHES)
Pristis pectinata
Pristis pristis

RAJIDAE (SKATES, RAYS)
Dipturus batis
Dipturus oxyrinchus
Leucoraja circularis
Leucoraja fullonica
Leucoraja melitensis
Leucoraja naevus
Malacoraja clavata
Raja asterias
Raja brchyura
Raja miraletus           
Raja montagui
Raja polystigma
Raja radula
Raja undulata
Rostroraja alba

RHINOBATIDAE (GUITARFISHES)
Glaucostegus cemiculus
Rhinobatos rhinobatos

RHINOPTERIDAE (COWNOSE RAYS)
Rhinoptera marginata

TORPEDINIDAE (ELECTRIC RAYS)
Tetronarce nobiliana
Torpedo marmorata
Torpedo torpedo

CHIMAERIDAE (RABBITFISHES, CHIMAERAS)
Chimaera monstrosa

THREATS

Sharks and rays are endangered most by incidental capture. 17 species are still under protection (including M. japonica), 12 being placed there in 2018 with the help of our foundation.

Acanthias vulgaris stocks have declined in the Black Sea due to overfishing.

Bycatch is a major threat for Guitarfish. Thankfully, they are now under protection after TUDAV’s initiative and application to relevant authorities.

Guitarfish under protection

Small spotted catshark, Scyliorhinus canicula

 

PROTECTED SPECIES ACCORDING TO STATEMENTS OF THE MINISTRY OF FOOD, AGRICULTURE AND LIVESTOCK OF TURKISH REPUBLIC REGULATING THE COMMERCIAL (No 4/1) AND AMATEUR (No. 4/2) FISHERIES

Figures are taken from the ‘Fishes of the Eastern Mediterranean’ book.

Below are the cartilaginous fish currently under protection in Turkey;

  • Cetorhinus maximus (Basking shark)
  • Carcharhinus plumbeus (Sandbar shark)
  • Squalus acanthias (Spiny dogfish)
  • Lamna nasus (Porbeagle)
  • Galeorhinus galeus (Tope)
  • Squatina oculata (Smoothback angelshark)
  • Squatina squatina (Angelshark)
  • Squatina aculeata (Sawback angelshark)
  • Rhinobatos rhinobatos (Blackfin guitarfish)
  • Rhinobatos cemiculus (Kemane balığı)
  • Oxynotus centrina (Angular rough shark)
  • Mobula mobular (Giant devilray)
  • Alopias vulpinus (Common thresher)
  • Isurus oxyrinchus (Shortfin mako)
  • Raja clavata (Thornback skate)
  • Squalus blainville (Longnose spurdog)

Further knowledge and research on cartilaginous fish is necessary and a priority as it is a crucial conservation strategy for our country.

Sampling for research

LET’S WORK TOGETHER!!!!!

Help us by sharing your photos of rays and sharks:

Join in the dissemination of knowledge and conservation of biodiversity. Let’s work together. Help us conserve these noble and extraordinary creatures.

Pristis pristis (Largetooth Sawfish)

IUCN ©R. Mitchell, CMS ©Marc Dando

Sawfish is a species of ray living in temperate and tropical shallow waters. Usually found lying on sandy, muddy bottoms, they mostly stay at depths less than 10 meters. They are facing extinction due to various anthropological factors such as fisheries pressure and habitat degradation.

Sawfish have been hunted down for their teeth, meat and fins for a long time. This slow-growing species reaches maturity at 10 years of age and has a small number of offspring. Their life span is estimated as being around 35 years. They can give birth to 1-9 young every two years. Their slow growth and increasing fishing pressures drove them into the brink of extinction (Florida Museum, 2018).

This species is critically endangered and has been the subject of incidental catch. Their elongated rostrum has been used as a blade.

Blades made from sawfish rostrum

Sawfish records from our waters are quite old. For this reason, our foundation is gathering distribution data of sawfish in our waters.

We will have humble prizes for anyone sharing pictures or other relevant information about sawfish in Turkish waters.

YOU CAN WIN A PRIZE…

PRESS RELEASES

ABOUT MANTA RAY FISHERIES

On 11 March 2017, 30 Manta rays were caught in the Mediterranean and landed in Izmir to be exported to Greece. The news was covered by Anadolu Agency (AA) and circulated via various agencies. On 14 March 2017, 14 of those have been sold off to a fisherman in Istanbul to be exhibited and the news was covered by Ihlas News Agency (IHA).

Fishermen lacked awareness of the protected state of this species via various multilateral agreements that Turkey is party to, as the prohibition of fishing, landing, selling and exhibiting Manta rays wasn’t included in the Statements of the Ministry of Food, Agriculture and Livestock of Turkish Republic regulating the Commercial (No 4/1) and Amateur (No. 4/2) Fisheries (No: 2016/35, 36).

The Manta rays were bycatches of a purse-seiner targeting commercially high-value fish such as tuna. Instead of releasing the rays back to the sea, this fisherman tried to make a profit out of them despite their low commercial value. Few studies that exist on the survival rates of Manta rays upon catch and release indicate that it’s best to release them directly from the brailer of the purse seine and refrain from handling, boarding or removing the fish altogether.

The catching, landing and exhibition of Manta rays became the focus of national and international NGO’s, academicians and the general public. Turkish Marine Research Foundation actively pursued this event since the beginning, and has undertaken the task of informing and mobilizing all relevant organizations.

Manta rays, also called Giant Devilrays and Spinetail Devilrays, are oceanodromous, pelagic cartilaginous fish belonging to the genus Mobula. This ovoviviparous species is found on the continental shelf and gives birth to 1 or 2 young in undetermined intervals. They are listed as ‘Endangered’ by IUCN so fishing, landing, exhibition, sale and trade of these species is forbidden by various international, national and regional regulations.

CMS Appendix I & II (2014), European Union (2015), IATTC (2015), and CITES (2016) restrict the fishing and/or trade of various Mobula spp. species. M. mobular is also listed in the GFCM (2015), Barcelona Convention SPA/BD Protocol Annex II (2001) and Bern Convention Appendix II (2001). Turkey is party to CITES and GFCM, as well as the Barcelona and Bern Conventions.

It is evident that public reaction has formed an awareness regarding the situation despite the insensitivity observed in this case. TUDAV will be tracking the mobilization of the relevant organizations in taking action and filling the legal loopholes on the subject.

Regards,

Endangered sharks and rays must be protected:

National Cartilaginous Fishes Conservation Programme is published!

 

REFERENCES

Send us your research in pdf form and it will be added to our references section.

Akyol, O., Erdem, M., Ünal, V., Ceyhan, T. (2005) Investigations on drift-net fishery for swordfish (Xiphias gladius L.) in the Aegean Sea. Turkish Journal of Veterinary and Animal Sciences 29: 1225-1231.

Akyol, O., Ünal, V., Capapé, C. (2015) Occurrence and biological observations on Angel Shark Squatina squatina (Chondrichthyes: Squatinidae) from the Turkish waters (Eastern Mediterranean). Turkish Journal of Fisheries and Aquatic Sciences 15: 925-929.

Akyüz, E., Artüz, I. (1957) Some observations on the biology of tuna (Thunnus thynnus) caught in Turkish waters. GFCM Proc Tech Papers 4: 93-99.

Başusta, N., Başusta, A., Özbek, E.Ö. (2016) Cartilaginous fishes and fisheries in the Mediterranean coast of Turkey. In: The Turkish Part of the Mediterranean Sea; Marine Biodiversity, Fisheries, Conservation and Governance (eds., C. Turan, B. Salihoğlu, E. Özgür Özbek, B. Öztürk), Turkish Marine Research Foundation (TUDAV), Istanbul, pp. 248-274.

Başusta, N., Erdem, U., Kumlu, M. (1998) Two new fish records for the Turkish seas: round stingray Taeniura grabata and skate stingray Himantura uarnak (Dasyatidae). Israel Journal of Zoology 44(1): 65-66.

Başusta, N., Özgür Özbek, E. (2017) New record of giant devil ray, Mobula mobular (Bonnaterre, 1788) from the Gulf of Antalya (Eastern Mediterranean Sea). J Black Sea/Mediterranean Environment 23(2): 162-169.

Bengil Tunka, E.G., Başusta, N. (2018) Chondrichthyan species as by-catch: A review on species inhabiting Turkish waters. J Black Sea/Mediterranean Environment 24(3): 288-305.

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Bilecenoğlu, M. (2008). Gökova Özel Çevre Koruma Bölgesi Boncuk Koyu Kum Köpekbalığı (Carcharhinus plumbeus) Koruma ve İzleme Projesi. Özel Çevre Koruma Kurumu Başkanlığı, T.C. Çevre ve Orman Bakanlığı, Ankara, 32 s.

Celik, S., Korun, J., Gokoglu, M., Ozvarol, Y. (2014) The marine leech Stibarobdella moorei (Oka, 1910) (Hirudinea, Piscicolidae) parasitic on the thornback ray Raja clavata Linnaeus, 1758 and angelshark Squatina squatina (Linnaeus, 1758) in Antalya Bay, Mediterranean Sea of Turkey. Helminthologia 51(3): 250-252.

Cilasın, M., Öztekin, A., Ayaz, A. (2015) Catching Efficiency and Catch Composition of the Trammel Nets (Marya Nets) Used in Çanakkale Region. Adıyaman University Journal of Science 5(2): 94-104.

Filiz, H. (2012). Gökova Özel Çevre Koruma Bölgesi Boncuk Koyu Kum Köpekbalığı (Carcharhinus plumbeus)’nın İzlenmesi (12 Mayıs – 28 Eylül 2012 Raporu), Muğla, 29 s.

Filiz, H. (2018) Year-round aggregation of sandbar shark, Carcharhinus plumbeus (Nardo, 1827), in Boncuk Cove in the southern Aegean Sea, Turkey (Carcharhiniformes: Carcharhinidae). Zoology in the Middle East 65(1): 35-39.

Filiz, H., Gulsahin, A. (2014) “One Year Monitoring of Sandbar Shark from a Special Environmental Protection Area in Turkey”. 8th International Symposium on Underwater Research.

Filiz, H., Irmak, E., Mater, S. (2005) Occurrence of Squatina aculeata Cuvier, 1829 (Elasmobranchii, Squatinidae) from the Aegean Sea, Turkey. EU Journal of Fisheries/Aquatic Science 22(3-4): 451-452.

Filiz, H., Mater, S. (2002) A preliminary study on length-weight relationships for seven elasmobranch species from North Aegean Sea, Turkey. EU J Fish Aqua Sci 19(3-4): 401-409.

Filiz, H., Yapıcı, S., Bilge, G. (2018) Chondrichthyan fishes in catch composition of the bottom trawl fishery on the coast of Didim, Turkey. Journal of the Black Sea/Mediterranean Environment. 24(1): 28-37.

Florida Museum (2018) Pristis pristis. Available at: https://www.floridamuseum.ufl.edu/ discover-fish/species-profiles/pristis-pristis/ (accessed 28 April 2020).

Godley, B.J., Gücü, A.C., Broderick, R.W., Furness, R.W., Solomon, S.E. (1998) Interaction between marine turtles and artisanal fisheries in the eastern Mediterranean: a probable cause for concern? Zoology in the Middle East 16: 49 – 64.

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Gücü A.C., Bingel F. (1994) Trawlable species assemblages on the continental shelf on the North Eastern Levant Seas(Mediterranean) with an emphasis on Lessepsian migration. Acta Adriatica 35: 83-100

Ismen, A., Cigdem Yigin, C., Altinagac, U., Ayaz, A. (2009) Length–weight relationships for ten shark species from Saros Bay (North Aegean Sea). J Appl Ichthyol 25: 109-112.

IUCN (2016) The Conservation Status of Sharks, Rays and Chimaeras in the Mediterranean Sea. Available at: https://www.iucn.org/sites/dev/files/content/documents/ brochure_medredlist_sharks.pdf (accessed 28 April 2020)

Kabasakal, H. (2003) Historical and contemporary records of sharks from the Sea of Marmara, Turkey. Annales Series Historical Naturalist 13: 1-12

Kabasakal, H., Kabasakal, O. (2014) Status of angelshark, Squatina squatina (Elasmobranchii: Squatiniformes: Squatinidae) in the Sea of Marmara. Annales Series Historia Naturalis 24(1): 41-46.

Kara, A., Sağlam, C., Acarli, D., Cengiz, Ö. (2017) Length-weight relationships for 48 fish species of the Gediz estuary, in İzmir Bay (Central Aegean Sea, Turkey). J Mar Biol Assoc UK 98(4): 879-884.

Karakulak, F.S., Erk, H., Bilgin, B. (2006) Length-weight relationships for 47 coastal fish species from the northern Aegean Sea, Turkey. Journal of Applied Ichthyology 22: 274-278.

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ÖÇK (2009) Gökova Özel Çevre Koruma Bölgesi Kum Köpekbalığı (Carcharhinus plumbeus) Türünün Korunmasi ve İzlenmesi Projesi Final Raporu, Ankara, 32 s.

Öğretmen, F., Yılmaz, F., Torcu Koç, H. (2005) An investigation on fishes of Gökova Bay (Southern Aegean Sea). Journal of Balikesir University Institute of Science and Technology 7: 19-36.

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Sakalli, A. (2017) Relationship between climate change driven sea surface temperature, Chl-a density and distribution of giant devil ray (Mobula mobular Bonnaterre, 1788) in Eastern Mediterranean: A first schooling by-catch record off Turkish coasts. YUNUS Research Bulletin 2017 1: 5-16.

Sakallı, A., Yücel, N., Capapé, C. (2016) Confirmed occurrence in the Mediterranean Sea of Mobula japanica (Müller & Henle, 1841) with a first record off the Turkish coasts. Journal of Applied Ichthyology 32: 1232-1234.

Soykan, C.U., Moore, J.E., Zydelis, R., Crowder, L.B., Safina, C., Lewison, R.L. (2008) Why study bycatch? An introduction to the Theme Section on fisheries bycatch. Endang Species Res Vol. 5: 91-102.

Yağlıoğlu, D., Deniz, T., Gürlek, M., Ergüden, D., Turan, C. (2015) Elasmobranch bycatch in a bottom trawl fishery in the Iskenderun Bay, northeastern Mediterranean. Cah Biol Mar 56: 237-243.

Yaglioglu, D., Turan C., Gurlek, M. (2013) On the occurrence of the giant devil ray Mobula mobular (Bonnaterre, 1788) from the Mediterranean coast of Turkey a by-catch documentation. Journal of Applied Ichthyology 29: 935-936.

Yucel, N., Sakalli, A., Karahan, A. (2017) First record of the honeycomb stingray Himantura leoparda (Manjaji-Matsumoto & Last, 2008) (Myliobatoidei: Dasyatidae) in the Mediterranean Sea, confirmed by DNA barcoding. Journal of Applied Ichthyology 33: 530-532.

Yığın, C.C., İşmen, A., Daban, B., Cabbar, K., Önal, U. (2019) Recent findings of rare sharks, Squatina oculata Bonaparte, 1840 and Squatina squatina (Linnaeus, 1758) from Gökçeada Island, Northern Aegean Sea, Turkey. Journal of the Black Sea/Mediterranean Environment. 25 (3): 305-314.

Squatina aculeata

Başusta, N. (2002) Occurrence of a sawback angelshark (Squatina aculeata Cuvier, 1829) off the Eastern Mediterranean coast of Turkey. Turk J Vet Anim Sci 26: 1177-1179.

Başusta, N. (2016) New records of neonate and juvenile sharks (Heptranchias perlo, Squatina aculeata, Etmopterus spinax) from the north-eastern Mediterranean. Sea. Mar. Biodiver. 46 (2): 525-527.

Ergenler, A., Turan, F., Turan, C. (2020) Occurrence of A Sawback Angelshark (Squatina aculeata Cuvier, 1829) from the Iskenderun Bay, North-Eastern Mediterranean Coast of Turkey. Biharean Biologist 14(1): 57-59.

Ergüden, D., Bayhan, Y. (2015) Three Fish Species Known to be Rare for Turkey, Captured from the Northeastern Mediterranean Coast of Turkey, Mersin Bay, Sudis hyalina Rafinesque, Chlopsis bicolor Rafinesque, Squatina aculeata Cuvier. International Journal of Scientific and Technological Research 1(4): 1-8.

Filiz, H., Irmak, E., Mater, S. (2005) Occurence of Squatina aculeata Cuvier, 1829 (Elasmobranchii, Squatinidae) from the Aegean Sea, Turkey. Ege J Fish Aqua Sci 22(3-4): 451-452.

Squatina oculata

Başusta N., Erdem U. (2000) A study on the pelagic and demersal fishes of Iskenderun Bay. Turkish Journal of Zoology 24: 1-19.

Ergüden, D., Ayas, D., Gürlek, M., Karan, S., Turan, C. (2019). First documented smoothback angelshark Squatina oculata Bonaparte, 1840 from the North-Eastern Mediterranean Sea, Turkey. Cahiers de Biologie Marine 60: 189-194.

Filiz, H., Togulga, M. (2002) Türkiye Denizlerindeki Ekonomik Elasmobranş Türleri, Balıkçılığı ve Yönetimi. Türkiye’nin Kıyı ve Deniz Alanları IV. Ulusal Konferansı, In: Türkiye Kıyıları 02 Bildiri Kitabı (eds., Özhan, E., Alpaslan, N.), Ankara, Turkey. pp. 717-726.

Yeldan, H., Avşar, D. (2006) Sediment structure and occurrence of skates and rays inhabiting in Babadillimani Bight located in Northeastern Mediterranean. Proceedings of the International Workshop on Mediterranean Cartilaginous Fish with Emphasis on Southern and Eastern Mediterranean, 14-16 October 2006, Istanbul-Turkey, pp. 35-41.

Yeldan, H., Avşar, D., Mavruk, S., Manaşırlı, M. (2013) Temporal changes in some Rajiformes species of cartilaginous fish (Chondrichthyes) from the west coast of İskenderun Bay (northeastern Mediterranean). Turkish Journal of Zoology 37: 693-698.

Yığın, C.C., İşmen, A., Daban, B., Cabbar, K., Önal, U. (2019) Recent findings of rare sharks, Squatina oculata Bonaparte, 1840 and Squatina squatina (Linnaeus, 1758) from Gökçeada Island, Northern Aegean Sea, Turkey. Journal of the Black Sea/Mediterranean Environment. 25 (3): 305-314.

List of Cartilaginous fishes of Turkey*

References*

Akyol, O. (2013). Record of the live sharksucker, E cheneis naucrates L innaeus, 1758 (O steichthyes: E cheneidae), from the northern A egean S ea (I zmir B ay, T urkey). Journal of Applied Ichthyology, 1(29), 263-264.

Akyol, O. K. A. N., Coker, T., & Perçin, F. (2011). The very rare and little‐known fishes along the coasts of Izmir (Aegean Sea, Turkey) in the past 40 years (1969–2008). Journal of Applied Ichthyology, 27(6), 1337-1345.

Avsar, D. (2001). Age, growth, reproduction and feeding of the spurdog (Squalus acanthias Linnaeus, 1758) in the South-eastern Black Sea. Estuarine, Coastal and Shelf Science, 52(2), 269-278.

BALCIOĞLU, E. B. (2019). Gökçeada kıyısal alan yüzey suyunda anyonik deterjan ve fosfat kirliliğinin araştırılması. Pamukkale University Journal of Engineering Sciences, 25(3).

Basusta, N., Erdem, U., & Kumlu, M. (1998). Two new fish records for the Turkish seas: round stingray Taeniura grabata and skate stingray Himantura uarnak (Dasyatidae). Israel Journal of Zoology, 44(1), 65-66.

Bengil, E. G. T., Başusta, A., & Başusta, N. (2018). Length-weight relationships of Glaucostegus cemiculus (Geoffroy Saint-Hilaire, 1817) from the Aegean Sea and northeastern Mediterranean coasts of Turkey. J. Black Sea/Mediterr. Environ., 24, 1-9.

Bengi̇l, E. G., Bengi̇l, F., & Özaydın, O. (2020). Feeding ecology and reproduction biology of Glaucostegus cemiculus (Geoffroy Saint-Hilaire, 1817) from the eastern Aegean Sea. Regional Studies in Marine Science, 33, 100952.

Bengil, F., Bengil, E. G., Mavruk, S., Heral, O., Karaman, O. D., & Ozaydin, O. (2019). Feeding ecology of four demersal shark species (Etmopterus spinax, Galeus melastomus, Scyliorhinus canicula and Squalus blainville) from the eastern Aegean sea. Turkish Journal of Fisheries and Aquatic Sciences, 19(6), 475-484.

Bilecenoglu, M., Taskavak, E., Mater, S., & Kaya, M. (2002). Checklist of the marine fishes of Turkey. Zootaxa, 113(1), 1-194.

Bilecenoğlu, M. (2008). Conservation and monitoring project of sandbar sharks (Carcharhinus plumbeus) in Boncuk Bay, Gökova special environmental protection area. Environmental Protection Agency for Special Areas, Republic of Turkey Ministry of Environment and Forestry, Ankara, 3-3.

Bok, T. D., Gokturk, D., Kahraman, A. E., Alicli, T. Z., Acun, T., & Ates, C. (2011). Length-weight relationships of 34 fish species from the Sea of Marmara, Turkey. Journal of Animal and Veterinary Advances, 10(23), 3037-3042.

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Demirhan, S. A., & Can, M. F. (2007). Length–weight relationships for seven fish species from the southeastern Black Sea. Journal of Applied Ichthyology, 23(3), 282-283.

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