Antalya körfezi littoralindeki makrobentik derisi dikenliler (Echinodermata) faunası ve mevsimsel dağılımlarını etkileyen bazı ekolojik faktörler
Macrobenthic echinoderm fauna of the littoral zone of the Gulf of Antalya and some ecological factors effecting their seasonal distribution
Yazar: ELİF ÖZGÜR ÖZBEK
Danışman: YRD. DOÇ. DR. EMİNE ŞÜKRAN OKUDAN ASLAN
Akdeniz Üniversitesi / Fen Bilimleri Enstitüsü / Su Ürünleri Mühendisliği Ana Bilim Dalı
Derece: Doktora, 2013
Konu: Biyoloji = Biology ; Su Ürünleri = Aquatic Products ; Zooloji = Zoology
Dizin: Akdeniz = Mediterranean ; Antalya Körfezi = Antalya Bay ; Bentos = Benthos ; Biyokütle = Biomass ; Biyolojik çeşitlilik = Biological diversity ; Dalma = Diving ; Dağılım = Distributions ; Derisi dikenliler = Echinodermes ; Ekoloji = Ecology ; Trol = Trawl

Özet:
Antalya Körfezi littoralinde derisi dikenli faunasına ait tür çeşitliliği, bolluğu ve biyokütlesinin belirlenmesi ve dağılımlarını etkileyen bazı ekolojik faktörlerin saptanmasını amaçlayan bu çalışmada mevsimsel olarak, Ağustos 2009- Nisan 2010 tarihleri arasında yumuşak substratlarda 6 istasyonda, 0-200 metre derinlikler arasında ve Ağustos 2010- Mayıs 2011 tarihleri arasında sert substratlarda 7 istasyonda, 0-30 metre derinlikler arasında örneklemeler gerçekleştirilmiştir. Yumuşak substratlarda örneklemeler, Akyarlar isimli ticari trol teknesi ile sekiz farklı derinlikte (5, 10, 25, 50, 75, 100, 150 ve 200 m) kum kapanı (van Veen grab) ve bentik kızak (sledge) çekimleri ve altı farklı derinlikte (25, 50, 75, 100, 150 ve 200 m) trol çekimleri yoluyla gerçekleştirilmiştir. Sert substratlarda örneklemeler SCUBA dalış ile 30 metre derinliğe kadar kayalık bölgelerin en alt derinlik sınırına kadar gerçekleştirilmiştir. Taranan hat uzunluklarına göre eşit aralıklarla 1m2lik kuadratlarda derisi dikenli bireylerinin sayımı ve örneklemeleri yapılmıştır. Örnekleme noktalarında deniz suyu ve sediment örnekleri alınmıştır.Örneklerin incelenmesi sonucunda, çalışma bölgesinde derisi dikenli filumuna ait, 5 klasis, 14 ordo, 30 familya, 39 cins ve 50 tür (1 Crinoid, 18 Asteroid, 14 Ophiuroid, 12 Echinoid, 5 Holothurid) tayin edilmiştir. Literatür bilgilerine göre 12 türün (Astropecten spinulosus (Philippi, 1837), Chaetaster longipes (Retzius, 1805), Hacelia attenuata Gray, 1840, Hymenodiscus coronata (G.O. Sars, 1872), Luidia ciliaris (Philippi, 1837), Luidia sarsi sarsi Düben & Koren, in Düben, 1845, Sclerasterias richardi (Perrier, 1882), Ophiacantha setosa (Bruzelius, 1805), Ophiura grubei Heller, 1863, Echinus melo Lamarck, 1816, Genocidaris maculata A. Agassiz, 1869, Spatangus purpureus O.F. Müller, 1776) Türkiye'nin Akdeniz kıyıları için ve Sclerasterias richardi (Perrier, 1882)'nin Türkiye denizleri için yeni kayıt olduğu belirlenmiştir. Bu çalışmada elde edilen 50 türün 42'si AM, 4'ü E, 2'si K ve 2'si IP kökenlidir. Endemik türler A. mediterranea, A. jonstoni, A. spinulosus ve P. microtuberculatus, kozmopolit türler A. squamata ve E. cordatum, Indo-Pasifik kökenli, yabancı türler ise O. savignyi ve S. reciprocans'tır.Örneklenen derisi dikenli komüniteleri arasında örnekleme metoduna göre önemli derecede fark bulunmuştur. Antalya Körfezi'nde yumuşak substratumda trol örneklemeleri ile 24, kızak örneklemeleri ile 32 ve grab örneklemeleri ile 22, sert substratumda SCUBA dalış örneklemeleri ile ise 7 derisi dikenli türü bulunmuştur.Antalya Körfezi'nde trol örneklemelerinden elde edilen E. sepositus `devamlı', A. mediterranea, A. placenta, C. longispinus, S. affinis, P. regalis ve sert substratumdan örneklenen P. lividus ve S. reciprocans `yaygın', diğer türler ise `nadir bulunan türler' olarak gruplanmıştır. En sık bulunan türler trol örneklemelerinde E. sepositus, kızak örneklemelerinde C. longispinus, grab örneklemelerinde A. filiformis ve sert substratumda SCUBA dalış örneklemelerinde P. lividus'dur. Önem derecelerine (Ö.D.) göre sırasıyla ilk beş tür, trol örneklemelerinde S. affinis, S. granularis, E. sepositus, A. mediterranea, P. regalis; kızak örneklemelerinde H. tubulosa, A. filiformis, H. mammata, P. microtuberculatus, A. mediterranea ve grab örneklemelerinde A. filiformis, E. cordatum, O. ophiura, A. mediterranea ve O. setosa'dır.Antalya Körfezi'nin sırasıyla Kaleiçi Yat Limanı ve Büyük Liman bölgelerinde yer alan C ve D istasyonlarında bulunan tür sayısının düşük olmasının mevcut antropojenik etkilerden kaynaklandığı, Manavgat Irmağı'nın denize döküldüğü alana yakın olan A istasyonunda ise düşük tür sayısının, düşük tuzluluk ve nehirle taşınan karasal kökenli materyalden kaynaklandığı düşünülmektedir. 75 ve 100 m'de bulunan yüksek derisi dikenli tür sayısı (34), bolluk ve biyokütlesinin bu derinliklerde bulunan yüksek kalsiyum karbonat (TKK) miktarı ile ilişkili olduğu bulunmuştur. Deniz suyunda birçok parametrenin mevsimsel olarak değişmesine rağmen, epifaunada mevsimsel bir değişim gözlenmemiş, infaunada ise en yüksek tür sayısı ve bolluğa sahip Ophiuridae mevsimsel değişim göstermiş, tür sayısı, bolluk ve biyokütlede kışın azalma görülmüştür.Derinlik, tuzluluk, NH4-N, TKK, TOK, %çakıl, %çamur ve %kum (0,5- 0,25mm) trol örneklemelerinde derisi dikenli bolluk ve biyokütle değişimlerini en iyi açıklayan parametrelerdir. Kızak örneklemelerinde derisi dikenli bolluk ve biyokütle değişimlerini en iyi açıklayan parametreler çözünmüş oksijen, %kum (1-0,5mm) ve %kum (0,125-0,063 mm), grab örneklemelerinde ise derinlik ve %kum (0,125-0,063 mm) olarak belirlenmiştir.Bentik fauna biyokütlesinin önemli bir yüzdesini oluşturan derisi dikenli türlerinin saptanması ile Antalya Körfezi'nde uzun süreli izleme çalışmaları için bir veri tabanı ve komünite yapılarındaki değişimleri ve bu değişimleri en iyi açıklayan çevresel parametrelerin belirlenmesi ile ileride yapılacak benzer çalışmalara altlık oluşturulması hedeflenmiştir.

Abstract:
The aim of this study is to investigate the species diversity, abundance and biomass of the echinoderm fauna in the littoral zone of the Gulf of Antalya and to determine some ecological factors affecting their distributions. Samplings were carried out seasonally in soft substrates at six stations, between the depths of 0-200 meters between August 2009 and April 2010 and in hard substrates at seven stations, between the depths of 0-30 meters, between August 2010 and May 2011. A commercial bottom trawler called Akyarlar was used for the samplings in the soft substrates. A total of 117 trawl hauls were carried out at six depth levels (25, 50, 75, 100, 150, 200 m) and 165 sledge hauls and grab (van Veen grab) samplings at eight depth levels (5, 10, 25, 50, 75, 100, 150, 200 m) in soft substrates. 32 SCUBA dives were conducted at four depth levels (0-5 m, 5-10 m, 10-20 m ve 20-30 m) to count and sample the echinoderm specimens inside 1 m2 quadrates located at equal intervals in the transects of hard substrates. Sea water and sediment samples were taken from the sampling points.As a result of the examination of the sampled specimens, 5 classis, 14 orders, 30 families, 39 genera and 50 species (1 Crinoid, 18 Asteroid, 14 Ophiuroid, 12 Echinoid, 5 Holothurid) belonging to the phylum of Echinodermata were determined in the study area.According to the literature 12 species (Astropecten spinulosus (Philippi, 1837), Chaetaster longipes (Retzius, 1805), Hacelia attenuata Gray, 1840, Hymenodiscus coronata (G.O. Sars, 1872), Luidia ciliaris (Philippi, 1837), Luidia sarsi sarsi Düben & Koren, in Düben, 1845, Sclerasterias richardi (Perrier, 1882), Ophiacantha setosa (Bruzelius, 1805), Ophiura grubei Heller, 1863, Echinus melo Lamarck, 1816, Genocidaris maculata A. Agassiz, 1869, Spatangus purpureus O.F. Müller, 1776) are new records for the Mediterranean coasts of Turkey and Sclerasterias richardi (Perrier, 1882) is a new record for Turkey. Among the total of 50 species found in this study, most species (42) have an Atlanto-Mediterranean distribution, while 4 are Mediterranean endemics, two are cosmopolitan and two are Lessepsian immigrants in the Mediterranean Sea. The Mediterranean endemics are A. mediterranea, A. jonstoni, A. spinulosus ve P. microtuberculatus and Lessepsian immigrants are O. savignyi and S. reciprocans.Significant differences were found between the echinoderm communities sampled by different sampling methods. 24 echinoderm species were sampled by trawl, 32 by sledge, 22 by grab and 7 by SCUBA diving. According to Soyer's frequency (F) index, E. sepositus was `continuous?, A. mediterranea, A. placenta, C. longispinus, S. affinis, P. regalis, P. lividus and S. reciprocans were `common? and the other 18 species sampled by trawl, 32 species sampled by sledge, 22 species sampled by grab and the other 5 species sampled by SCUBA diving were rare species. The most frequent species were E. sepositus in trawl samplings, C. longispinus in sledge samplings, A. filiformis in grab samplings and P. lividus in the hard substrates.According to the importance values of the species, the first five species were S. affinis, S. granularis, E. sepositus, A. mediterranea, P. regalis in the trawl samplings; H. tubulosa, A. filiformis, H. mammata, P. microtuberculatus, A. mediterranea in the sledge samplings and A. filiformis, E. cordatum, O. ophiura, A. mediterranea ve O. setosa in the grab samplings.Significant differences were found between the stations in the number of echinoderm species sampled by all different sampling methods and in the communities sampled by trawl and sledge. In soft substrates, 30 echinoderm species were found in the station A, 37 in B, 18 in C, 17 in D, 39 in E and 35 in F. In hard substrates 1 species were found in the station 1, 2 in 2, 3 in 3, 5 in 4 and 3 in 7. No echinoderm species was found in the stations 5 and 6. The overall average abundance were high in the stations of B, E, F, A, D, and C in trawl samplings; stations of C, A, B, E, F and D in sledge samplings and E, F, A, B, C, and D in grab samplings, respectively. The overall average biomass were high in the stations of E, B, A, F, D, and C in trawl samplings; stations of C, B, E, F, D and A in sledge samplings and B, E, F, A, C and D in grab samplings, respectively.The lowest species numbers of the stations C and D, located in the Kaleiçi Marina ve Great Harbour of Antalya, in comparison with those of other stations should mainly be attributed to the high anthropogenic effects present in these stations. The low species number of the station A, where is located in the mouth of Manavgat River, should be a result of the very peculiar oceanographic conditions prevailing in the area, especially the low salinities and terresterial material carried by the river to the sea.Significant differences were found between the depth levels in the number of echinoderm species sampled by all different sampling methods and in the communities sampled by trawl and sledge. In soft substrates, 8 echinoderm species were found in the depth of 5 m, 15 in 10 m, 25 in 25 and 50 m, 34 in 75 and 100 m, 26 in 150 m and 19 in 200 m. In hard substrates 3 species were found in the depth of 0-5 m, 2 in 5-10 m, 4 in 10-20 m and 3 in 20-30 m. The reason of the highest species numbers of the depths of 75 and 100 m was found to be mainly related to the high calcium carbonate levels (CaCO3) in these depth levels.The overall average abundance were high in the depths of 75 m, 100 m, 150 m, 200 m, 50 m, and 25 m in trawl samplings; depths of 10 m, 75 m, 100 m, 25 m, 150 m, 50 m, 200 m, and 5 m in sledge samplings and 75 m, 25 m, 100 m, 50 m, 10 m, 150 m, 200 m, and 5 m in grab samplings, respectively. The overall average biomass were high in the depths of 100 m, 75 m, 200 m, 150 m, 50 m, and 25 m in trawl samplings; depths of 10 m, 25 m, 75 m, 200 m, 100 m, 5 m, 50 m and 150 m in sledge samplings and 75 m, 25 m, 100 m, 10 m, 150 m, 50 m, 200 m and 5 m in grab samplings, respectively.No significant seasonal differences were found in the number of echinoderm species and communities sampled by trawl and sledge. However, significant seasonal differences were found in the number of echinoderm species sampled by grab. In all samplings, 45 echinoderm species were found in summer, 43 in autumn, 35 in winter and 43 in spring. The overall average abundance were high in summer, spring, winter, and autumn in trawl samplings; autumn, spring, summer and winter in sledge samplings and summer, spring, autumn, and winter in grab samplings, respectively. The overall average biomass were high in summer, spring, autumn, and winter in trawl samplings; autumn, winter, spring, and summer in sledge samplings and summer, spring, autumn, and winter in grab samplings, respectively.Although many parameters in sea water differ seasonally, no significant seasonal differences were found in the epifauna. However, Ophiuridae, possessing the highest species number and abundance in endofauna, showed seasonal difference and exibited low species number, abundance and biomass in winter.For the echinoderm abundance data in trawl samplings, the model that achieved the lowest value of AIC (and therefore was the best model on the basis of this criterion) had seven variables of environmental parameters (depth, salinity, NH4-N, total CaCO3, %pebble, %mud and %sand (0,5- 0,25mm)) explaining 25.4% of the variability in the data cloud. For the echinoderm biomass data, the best model had six variables of environmental parameters (depth, salinity, NH4-N, total CaCO3, total organic carbon and %pebble) explaining 24,1% of the variability.For the echinoderm abundance data in sledge samplings, the best model had three variables of environmental parameters (dissolved oxygen, %sand (1-0,5mm) and %sand (0,125-0,063 mm)) explaining 8,9% of the variability. For the echinoderm biomass data, the best model had two variables (dissolved oxygen and %sand (0,125-0,063 mm)) explaining 7,1% of the variability.For the echinoderm abundance and biomass data in grab samplings, the best model had two variables of environmental parameters (depth and %sand (0,125-0,063 mm)) explaining 10,3% and 9,5% of the variability, respectively.Echinoderm species constitutes a significant percentage of the benthic biomass. By determining the echinoderm fauna of the Gulf of Antalya and environmental parameters best explaining the changes in the community structures, this study provides a database for the further research and monitoring programmes.