Scleractinian anthozoans, commonly known as hard corals, are one of the most important and distinctive groups among all marine species in the seas and oceans. Their ecological value has increased in recent years (Waller 2005). Formation of the hard substrate, which is highly important as a habitat for shelter, feeding, nursing and breeding, is the main benefit to other organisms such as fish, crustaceans, echinoderms, sponges, mollusks and polychaetes. With the help of these communities, overhangs, colony banks, encrusted rocky walls and coralligenous formations support a variety of life around these areas (Zibrowius 1980; Fabri et al. 2014).
The Mediterranean Sea is an important marine ecosystem with less than 5% of the total number (over 6000) of coral species distributed throughout the world (OCEANA 2004). Although it is a reserve for a very limited number of anthozoans when compared to those living in the tropics, the scleractinians living as both solitary animals or in colonies, also form diverse and complex habitats with their specific characteristics. Due to the coralligenous formations and other calcareous bio-concretions around the rocky substrate, also accepted as major contributors to coral frameworks, the area may be considered as a coral reef system in its ecosystem (Kružic & Požar-Domac 2003; Ballesteros 2006; Kružic & Rodic 2008; Coll et al. 2010). Whether or not the Mediterranean scleractinians do not basically create the reef form, their geographical and bathymetrical limits are broader (Barbeitos et al. 2010). Owing to the contribution of the Mediterranean to the biodiversity and the increased habitat loss resulting from the global warming, studies of these species have recently also increased around these regions. To date, a number of surveys have been carried out on benthic invertebrates distributed in the Mediterranean, Aegean, Marmara and Black Sea coasts of Turkey. However, coral facies that are also highly important to other aquatic species have not yet been thoroughly researched with regard to the community structure. This caused data deficiency on taxonomy, ecology, biology and distributional features of the species over time. Although the complete checklist of anthozoans has recently been released for the Turkish coasts (Çinar et al. 2014), scleractinian corals are still the least studied order among marine species groups.
In Turkey, the anthozoan studies started with new geographical reports from the Aegean Sea (Forbes 1844). During surveys conducted by the author, two scleractinian species (
The Turkish Straits System and the Marmara Sea have been important to the research on corals in Turkey since the end of the 1800s.
The 1970s, more comprehensive surveys were conducted on zoogeographic and ecological features of the species at the Aegean Sea coasts of Turkey. The first information on the anthozoan fauna of the above-mentioned area was provided by Bacescu et al. (1971), Geldiay & Kocataş (1972), Coşar (1974) and Kocataş (1978). The huge effort made by Zibrowius’ (1979, 1980), so far the most extensive research on scleractinians around the Mediterranean Sea, added four species
In addition to these data, Gözcelioglu (2011) added 10 coral species (Hexacorallia, Octocorallia) to the scleractinian inventory, three of which (
The surveys in the Turkish coasts were limited until 2011 and only some distributional records which did not cover the ecological and morphological features of species were released. Some limited ecological information regarding the Scleractinia was also given in the references. However, the particular point as to the more advanced assessments of the subject began with the surveys in the Dardanelles (Özalp & Alparslan 2011). This was also a critical time because a scleractinian corallite was subjected to a detailed laboratory procedure and in-situ measurements regarding the marine ecology were performed for the first time in Turkey. The Dardanelles (Çanakkale Strait) as part of the Turkish Straits, has served as a significant sampling area in other researches. When considering the current knowledge, it can be observed that there are a number of ongoing investigations into the benthic invertebrate fauna of the strait (Çelik et al. 2007; Palaz et al. 2010; Ateş et al. 2014). During the first regional ROV observations referred to as the MARNAUT cruise onboard the French R/V
No thorough research has been carried out in the past few years on the species taxonomy, ecology, morphology and regional distribution in the above-mentioned coastal waters. Although some studies made a major contribution to the zoogeographical data, the knowledge of scleractinians is still scarce. In this sense, the current investigation carried out in the Dardanelles and the Marmara Sea represents the initial stage of a large-scale research on hard coral communities occurring in the Turkish seas.
The Dardanelles is known as the longest and deepest waterway of the Turkish Straits System, which extends nearly 65 km between the eastern coasts of the Gallipoli peninsula (Seddülbahir-Gelibolu) and the coastline of Çanakkale city up to Lapseki province (Fig. 1). It is an important connection between the Aegean and Black Sea via the Marmara Sea and Bosphorus. There are two current systems in the strait with some special areas such as the Capes of Nara and Eceabat, where strong water turbulence occurs. While the more saline Aegean waters enter the Marmara Sea as the bottom layer, the upper flow on the surface transports the waters of the Black Sea into the Aegean Sea (Beşiktepe 2003). The salinity and temperature values range from 20 to 40 (PSU) and from 6 to 20°C, respectively. In summer time, temperature of 25°C may also be observed at some locations (Baba et al. 2007; Özalp 2012). The Nara Cape where currents have the highest speed (150 cm s-1) in the strait is the narrowest (1260 m) and the deepest point with the maximum depth of 113 m.
This area has a coarser sediment compared to other areas (Gökaşan et al. 2008). The Dardanelles is a specific habitat representing the abundance of the Mediterranean species. The dense occurrence of seagrasses such as
There is also an extensive spread of coralligenous concretions around the rocky substrate. Due to its benthic features, affected mainly by the Aegean deep waters, the Dardanelles resembles the Mediterranean ecological conditions to some extent (Özalp & Alparslan 2011; Özalp & Ateş 2015; Topçu & Öztürk 2015).
This study was carried out mainly in the Dardanelles (Çanakkale Strait) at 197 stations to a maximum depth of 50 m during the BASI coral research, between 2011 and 2014 (Fig. 2). Three sampling stations were also selected as pilot locations in the south of the Marmara Sea to compare the scleractinian distribution and ecological features. SCUBA equipment was the main tool during the ecological research in situ. For some other critical stations where the current was strong and effective up to deep waters, technical diving instruments also supported the field studies. A scooter was also used throughout the surveys to observe the characteristic of benthos. Assessment of the species occurrence, as well as ecological, biological and distributional measurements were conducted at six different depth levels (0-5 m; 6-10 m; 11-20 m; 21-30 m; 31-40 m; 41-50 m). At the first depth level (0-5 m), both SCUBA and free diving techniques were used as required. The manta-tow technique (one of the most suitable methods for monitoring the coral reefs in the tropics) was successfully applied at all stations between 0 and 5 m depth, where the visibility is good (Kenchington 1978).
During these studies, a free diver was towed at certain intervals behind the research vessel by holding a rope (20 m) and a total of 324 tows were carried out along the Dardanelles coasts up to the initial point of the Marmara Sea (Karabiga stations included) and the distributional pattern of species, the substrate type, the number of individuals (or colonies) and GPS points were noted on the data sheet. Since the sandy substrates cover a larger area than rocky habitats in the strait, there was no fixed timing during the tow survey. Thus, the intervals varied depending on the benthic character of the region so that some nonstop tows lasted about two hours. The SCUBA manta-tow technique was also used approximately once for each station to check the general occurrence of species around the rocky substrates. The 50 m transect and visual counting were the suitable methods for colonial corals to determine their abundance, the number of individuals and the cover area, while a 20 × 20 cm quadrat technique was randomly applied to solitary species with the same purpose.
For colonial species (Fig. 3), lengths of D1/ D2 and height of each colony (H) were measured with a plastic ruler under the water (D1: Width 1; D2: Width 2; H: Height of a colony measured from the substrate). The total corallite number for each colony was estimated with a 2 × 2 cm quadrat (Peirano et al. 2001). For solitary and colonial species, length, width and height of the sampled individual corallite were also measured (Length: the maximum axis of the oral disc; Width: the minimum axis of the oral disc; H: height of a corallite individual) (Caroselli et al. 2012). A 20 × 20 cm quadrat was also used to determine the abundance of solitary individuals (Bianchi et al. 2004).
In addition to the above measurements, all specimens were photographed and recorded with a wide-angle featured HD camera in situ and the ecological characteristics such as temperature (by depth), substrate type, bottom declination, depth at which a species occurred and the water current were determined. Macro photographs of the species were also taken. Salinity was another physicochemical factor measured, representative of 15 stations (rocky habitats).
To prevent habitat damage, only 10 corallites were carefully sampled with pliers from the main colony or its position on the rock, and later used in biomass analyses. All collected corallites were first washed in clean water, soaked in H2O2 solution (Peirano et al. 2001) for about three days to remove the organic matter and then dried at 80°C for 48 hours in a laboratory. To determine the skeletal weight, ten corallites representing one colony were weighed on an analytical balance. These procedures were followed by the examination of skeleton structures under an Olympus binocular stereo microscope for taxonomic analyses. The photograph of each corallite structure was also taken under the microscope via an Olympus HD camera. Later, all specimens were deposited in the Piri Reis Naval Museum, the Faculty of Marine Science and Technology, the University of Çanakkale Onsekiz Mart, with the pre-code “OM/PRM”.
The dried corallites were examined for morphological differences in calyx, columella, palus, coenosteum, costa, theca, septa and basal structure. The scleractinian species reported here were taxonomically identified according to Zibrowius (1980). For each colony, mean values of ecological characteristics such as biomass, the total number of corallites, the total number of colonies, dimensions of corallites (the greatest length and the smallest length of a calix, height of corallites) and the cover rate on the substrate were determined by using PAST and MTB software and standard errors were given. The frequency and dominance of species was calculated using the Soyer’s (1970) (F%) and Bellan-Santini’s (1969) dominancy index (DI%), respectively.
The frequency index was estimated by:
where
where
A total of nine scleractinian coral species, two of them zooxanthellates, were found between 0 and 50 m in this study, five of which were reported for the first time from the Dardanelles. Four of them were solitary species, while five were colonial. According to the recently updated anthozoan list from the Turkish Seas, 75 corals (15 scleractinians) have been recorded to date. For instance, the Marmara Sea is represented by 52 species, nine of which are the hard corals (Çinar et al. 2014). Considering the checklist, the colonial coral
Phylum CNIDARIA
Class ANTHOZOA
Order SCLERACTINIA
Suborder ASTROCOENIINA
Family POCILLOPORIDAE
Family FAVIIDAE
Family CARYOPHYLLIIDAE
the species were given from the Atlantic Ocean by Zibrowius and Saldanha (1976), Monteiro et al. (2013); from the Mediterranean by Zibrowius (1980) and Koukouras (2010); from the Aegean Sea by Zibrowius (1979) and Sini et al. (2014). The first reports from the Aegean and Mediterranean Sea coasts of Turkey were released by Zibrowius (1979) and Çinar et al. (2014), respectively. The occurrence of the species in the Marmara Sea and Dardanelles is newly recorded.
Family DENDROPHYLIIDAE
Dardanelles. Sometimes observed in dense clusters resembling the colony structure. Younger corallites rarely grow on large individuals. Columella porous, broad and elliptical. Theca ribbed, serrate and at some points with holes. Septa slightly visible (Fig. 11).
In total, 208 colonies and 556 solitary individuals (polyps/corallites) belonging to four families were observed on rocky, gravelly and shingly substrates at 200 stations. Sixty seven stations were excluded from the statistical assessment due to the nonexistence of the species. Ten corallites per colony/individual were assessed.
According to Soyer’s Index,
The largest total number of
Dendrophylliidae and Caryophylliidae are the dominant families of the colonial and solitary corals, respectively. Although these Mediterranean originated corals are rare in the studied areas and their occurrence is limited to the rocky substrate, their presence in the Marmara Sea is still remarkable.
At only 17 stations out of the 133 studied ones (4 replicated assessments at six depth ranges), the number of species was more than two. The correspondence analysis was conducted in relation to the number of stations where at least two species occurred. As a result, there was a clear relation between the stations 45 and 103 for
Similarly, the distance of
The mean morphological diameters and coral cover values are presented in the tables (Tables 1, 2). Stations with the zero mean value (i.e. study stations where only one colony or solitary individuals of the coral species occurred) were excluded from the assessments, but they were added to the tables to provide the ecological information.
Colonial corals, morphological diameters and coral cover values assessed per station
TNC | Covering Area |
Total Biomass |
Length |
Width |
Height |
|
---|---|---|---|---|---|---|
(cm2) |
(g) |
(cm) |
||||
Mean±SE (Range) | ||||||
Station 1 | 674.5±329.5 (345-1004) | 2850±550 (2300-3400) | 285.3±87.15 (198-372) | 77±1 (76-78) | 37.5±7.5 (30-45) | 6±1 (5-7) |
Station 45 | 761±41 (720-802) | 2340±400 (1900-2700) | 70.09±12.31 (57-82) | 64±4 (60-68) | 36±4 (32-40) | 3±1 (2-4) |
Station 1 | 112±17 (16-300) | 630±150 (80-2100) | 4.979±0.384 (2.81-9.9) | 29.83±3.113 (17-61) | 19.28±2.15 (10-39) | 9.17±1.17 (2-19) |
Station 2 | 214±84 (64-355) | 520±100 (350-710) | 2.873±0.576 (2.1-4) | 26.67±2.96 (21-31) | 19.23±1.86 (17-23) | 8.33±2.33 (4-12) |
Station 3 | 251±19 (67-1000) | 2400±140 (570-6900) | 5.412±0.185 (2.64-10.14) | 56.77±1.59 (30-96) | 41.31±1.38 (19-72) | 8.4±0.35 (3-20) |
Station 4* | 112 (112) | 300 (300) | 3.43 (3.43) | 26 (26) | 14 (14) | 5 (5) |
Station 20 | 1518±1408 (110-2925) | 1240±1160 (80-2400) | 5.48±1.22 (4.26-6.69) | 31±32.5 (23-54) | 28±25.5 (10-46) | 14±14.1 (4-24) |
Station 24* | 78 (78) | 800 (800) | 5.54 (5.54) | 30 (30) | 27 (27) | 8 (8) |
Station 41* | 23 (23) | 100 (100) | 3.44 (3.44) | 15 (15) | 7 (7) | 3 (3) |
Station 1 | 73±12 (19-270) | 610±170 (100-4600) | 4.082±0.35 (1.9-8.6) | 20.69±2.18 (9-60) | 28.54±2.65 (13-78) | 5.11±0.5 (2-11) |
Station 2 | 71±12 (32-136) | 240±50 (140-600) | 4.537±0.422 (1.8-5.75) | 10.44±1.21 (7-18) | 22.78±2.17 (18-34) | 5.67±1.08 (2-11) |
Station 21* | 40 (40) | 100 (100) | 3.1 (3.1) | 8 (8) | 21 (21) | 3 (3) |
Station 45 | 228±52 (30-1600) | 7540±4220 (90-151000) | 3.585±0.152 (1.94-5.6) | 47.7±9.74 (6-345) | 66.4±13.5 (15-440) | 6.56±0.61 (2-17) |
Station 51* | 90 (90) | 700 (700) | 4.66 (4.66) | 30 (30) | 26 (26) | 6 (6) |
Station 52* | 40 (40) | 100 (100) | 3.51 (3.51) | 10 (10) | 15 (15) | 2 (2) |
Station 56* | 140 (140) | 1200 (1200) | 4.4 (4.4) | 30 (30) | 40 (40) | 4 (4) |
Station 103 | 37±7 (23-55) | 20±3 (10-30) | 3.105±0.434 (2.17-4.21) | 4.75±0.47 (4-6) | 5.5±0.95 (4-8) | 3.5±0.28 (3-4) |
Station 104* | 46 (46) | 200 (200) | 4.88 (4.88) | 10 (10) | 20 (20) | 4 (4) |
Station 108 | 212±176 (36-388) | 950±850 (100-180) | 4.045±0.205 (3.84-4.25) | 19±5 (14-24) | 43.5±31.5 (12-75) | 7.5±4.5 (3-12) |
Station 109* | 41 (41) | 400 (400) | 2.23 (2.23) | 22 (22) | 21 (21) | 4 (4) |
Station 110* | 86 (86) | 900 (900) | 3.24 (3.24) | 22 (22) | 41 (41) | 4 (4) |
Station 117 | 108±21 (10-423) | 510±100 (30-1700) | 4.66±0.219 |
16.29±2.33 |
19.95±1.99 |
4.04±0.51 |
Station 140* | 12 (12) | 20 (20) | 1.68 (1.68) | 4 (4) | 7 (7) | 4 (4) |
Station 2* | 210 (210) | 2000 (2000) | 17 (17) | 41 (0-41) | 55 (0-55) | 21 (0-21) |
Solitary corals, morphological diameters calculated per station
TNI | Total Biomass |
Length |
Height |
|
---|---|---|---|---|
(g) |
(cm) |
|||
Mean±SE (Range) | ||||
Station 6* | 18 (18) | 28.53 (28.53) | 0.65±0.15 (0.5-0.8) | 1.2±0.2 (1-1.4) |
Station 27* | 18 (18) | 10.42 (10.42) | 0.34±0.05 (0.15-0.5) | 0.96±0.06 (0.6-1.2) |
Station 103* | 18 (18) | 15.63 (15.63) | 0.59±0.03 (0.4-0.9) | 0.76±0.05 (0.5-1.2) |
Station 140 | 96±128 (6-187) | 18.43±11.78 (10.1-26.76) | 1.87±0.11 (1.69-2.1) | 1.67±0.19 (1.4-1.8) |
Station 141* | 31 (31) | 24.66 (24.66) | 1.74±0.09 (1.59-1.82) | 1.56±0.06 (1.5-1.7) |
Station 142* | 131 (131) | 8.24 (8.24) | 1.92±0.11 (1.69-2.1) | 1.64±0.15 (1.5-1.8) |
Station 1* | 6 (6) | 2.49±0.67 (2.01-2.97) | 0.65±0.15 (0.5-0.8) | 1.2±0.2 (1-1.4) |
Station 45 | 16±9 (6-25) | 2.61±0.57 (1.98-3.09) | 0.34±0.05 (0.15-0.5) | 0.96±0.06 (0.6-1.2) |
Station 103* | 137 (137) | 2.91 (2.91-2.91) | 0.59±0.03 (0.4-0.9) | 0.76±0.05 (0.5-1.2) |
Station 117* | 6 (6) | 1.88 (1.88-1.88) | 0.6 (0.6-0.6) | 0.9 (0.9-0.9) |
Station 1* | 18 (8) | 8.8 (8.8) | 0.6±0.06 (0.6-0.8) | 1.1±0.5 (1-1.2) |
Station 2* | 12 (12) | 8.21 (8-21) | 0.6±0.1 (0.5-0.7) | 1.05±0.05 (1.-1.1) |
Station 45 | 8±5 (6-18) | 9.15±0.88 (7.89-10.11) | 0.87±0.14 (0.5-1.2) | 1.4±0.15 (1-1.7) |
Station 51* | 6 (6) | 9.13±1.52 (8.05-10.2) | 1.05±0.05 (1-1.1) | 1.45±0.05 (1.4-1.5) |
Station 52* | 6 (6) | 9 (6) | 1.8 (1.8) | 1.5 (1.5) |
Station 56* | 12 (12) | 8.77 (6) | 0.9±0.3 (0.6-1.2) | 1.35±0.35 (1-1.7) |
Station 103* | 18 (18) | 6 (6) | 0.8±0.1 (0.7-1) | 1.2±0.15 (1-1.5) |
Station 104* | 6 (6) | 7.55 (7.55) | 0.5 (0.5) | 1 (1) |
Station 108* | 6 (6) | 6.54 (6.54) | 0.7 (0.7) | 1.2 (1.2) |
Station 117* | 6 (6) | 11.3 (11.3) | 0.7 (0.7) | 1.1 (1.1) |
Station 1* | 12 (12) | 29.9 (29.9-29.9) | 1.65±0.25 (1.4-1.9) | 2.65±0.15 (2.5-2.8) |
Station 2* | 6 (6) | 24 (24-24) | 1.4 (1.4-1.4) | 2.5 (2.5-2.5) |
Station 3* | 6 (6) | 21.98 (21.98-21.98) | 0.6 (0.6-0.6) | 1.6 (1.6-1.6) |
Station 9* | 6 (6) | 25 (25-25) | 1 (1-1) | 2.1 (2.1-2.1) |
Station 10* | 6 (6) | 21.28 (21.28-21.28) | 1.9 (1.9-1.9) | 3 (3) |
Station 11* | 12 (12) | 13.9 (13.9-13.9) | 0.75±0.05 (0.7-0.8) | 1.75±0.15 (1.6-1.9) |
Station 18* | 12 (12) | 10.66 (10.66-10.66) | 0.75±0.05 (0.7-0.8) | 1.35±0.15 (1.2-1.5) |
Station 20* | 6 (6) | 33.95 (33.95) | 0.7 (0.7) | 1.6 (1.6) |
Station 23* | 6 (6) | 28.3 (28.3) | 1.8 (1.8) | 2.3 (2.3) |
Station 24* | 12 (12) | 20 (20) | 1.4±0.3 (1.1-1.7) | 2.5±0.1 (2.4-2.6) |
Station 26* | 6 (6) | 24.41 (24.41) | 1.1 (1.1) | 1.9 (1.9) |
Station 27 | 122±116 (6-237) | 32.97±4.53 (28.44-37.5) | 1.32±0.07 (0.5-2.4) | 2.54±0.1 (1.2-3.9) |
Station 30* | 12 (12) | 12.65 (12.65) | 0.7±0.1 (0.6-0.8) | 1.3±0.1 (1.2-1.4) |
Station 35* | 12 (12) | 14.2 (14.2) | 1.15±0.05 (1.1-1.2) | 2.2±0.3 (1.9-2.5) |
Station 38* | 18 (18) | 12.47 (12.47) | 1.4±0.11 (1.2-1.6) | 2.43±0.32 (1.8-2.9) |
Station 39* | 18 (18) | 11.98 (11.98) | 1.73±0.12 (1.5-1.9) | 2.5±0.2 (2.2-2.9) |
Station 40* | 18 (18) | 10.1 (10.1) | 1.36±0.03 (1.3-1.4) | 2.36±0.06 (2.3-2.5) |
Station 41* | 6 (6) | 15.45 (15.45) | 1.1 (1.1) | 1.8 (1.8) |
Station 42* | 6 (6) | 15 (15) | 1.3 (1.3) | 1.9 (1.9) |
Station 43* | 6 (6) | 14.64 (14.64) | 0.8 (0.8) | 1.9 (1.9) |
Station 44* | 6 (6) | 12.08 (12.08) | 1.3 (1.3) | 2.2 (1.9) |
Station 103* | 6 (6) | 42 (42) | 1.6 (1.6) | 2.5 (2.5) |
Station 117* | 6 (6) | 16.76 (16.76) | 2.3 (2.3) | 2.2 (2.2) |
Station 119* | 6 (6) | 11.4 (11.4) | 1.1 (1.1) | 2 (2) |
Station 1 | 87±6 (81-93) | 7.79±0.63 (7.16-8.42) | 1.57±0.04 (1.2-1.5) | 1.09±0.02 (0.8-1.4) |
Station 2 | 49±12 (37-62) | 4.21±0.1 (4.11-4.32) | 1.59±0.06 (1.2-1.5) | 1.08±0.03 (0.8-1.4) |
Station 21* | 6 (6) | 4.19 (4.19-4.19) | 1.5 (1.5) | 1.1 (1.1) |
Station 45 | 124±56 (68-181) | 11.67±3.03 (6.64-14.7) | 1.41±0.02 (1.1-1.4) | 2.41±0.12 (1.5-3.9) |
Station 51* | 6 (6) | 11.18 (11.18) | 1.5 (1.5) | 1.1 (1.1) |
Station 52* | 6 (6) | 12.43 (12.43) | 1.3 (1.3) | 1.5 (1.5) |
Station 56* | 6 (6) | 9.86 (9.86) | 1.5 (1.5) | 3 (3-3) |
Station 104* | 6 (6) | 8.89 (8.89) | 1.4 (1.5) | 1.4 (1.4) |
Station 108* | 6 (6) | 18.85 (18.85) | 1.4 (1.4) | 3.1 (3.1) |
Station 109* | 6 (6) | 12.71 (12.71) | 1.5 (1.5) | 1.1 (1.1) |
Station 110* | 6 (6) | 10.65 (10.65) | 1.4 (1.4) | 1.8 (1.8) |
Station 117* | 50 (50) | 12.5 (12.5) | 1.22±0.1 (1-1.5) | 1.66±0.13 (1.3-2) |
Station 140* | 850 (850) | 4.22 (4.22) | 0.48±0.02 (0.4-0.6) | 0.67±0.03 (0.5-0.9) |
Of the 14 stations, the maximum MNC of
The largest number of corallites from one group was found at 23 m depth, i.e. 137 individuals (Station 103). The highest MNC among five groups of
The abundance of the rocky substrate and its cover area were calculated in the assessment of the coral cover.
Since the distributional area of corals is small, only stations with a dense cover of colonial corals were included in the calculations.
Coral cover determined in terms of the rocky substrate range at the stations with the highest species abundance
Station/tars (m2) |
species/cover area (m2) |
|||
---|---|---|---|---|
Sta 1 – 800 | 0.63 | 1.14 | 1.58 | - |
Sta 2 – 410 | - | 0.15 | 0.22 | 0.2 |
Sta 3 – 350 | - | 18.11 | - | - |
Sta 20 – 200 | - | 0.24 | - | - |
Sta 45 – 1120 | 0.48 | - | 27.89 | - |
Sta 108 – 208 | - | - | 0.19 | - |
Sta 117 – 110 | - | - | 1.07 | - |
TARS: Total Spreading Area of Rocky Substrate at a given station; Cover area: total cover area of the species at a station
Rock-based percent cover of
Colony’s number |
Cover Area (m2) |
Surface Area of Rock (m2) |
Percent Cover on Rock (%) |
|||
---|---|---|---|---|---|---|
p1 | 0.009 | 0.33 | 2.72 | |||
p2 | 0.036 | 0.42 | 8.57 | |||
p3 | 0.09 | 0.33 | 27.27 | |||
p4 | 0.03 | 0.19 | 15.7 | |||
p5 | 0.039 | 0.18 | 21.6 | |||
p6 | 0.032 | 1.01 | 3.16 | |||
p7 | 0.03 | 0.3 | 10 | |||
p8 | 0.15 | 0.68 | 22.05 | |||
p9 | 0.036 | 0.33 | 10.9 | |||
p10 | 4.8 | 7.6 | 63.15 | |||
p11 | 2.2 | 2.76 | 79.71 | |||
p12 | 1.1 | 3 | 36.6 | |||
p13 | 15.1 | 20 | 75.5 | |||
p14 | 0.08 | 1.15 | 6.95 | |||
p15 | 0.12 | 0.15 | 80 | |||
p16 | 0.02 | 0.18 | 11.1 | |||
p17 | 0.03 | 1.26 | 2.38 | |||
p18 | 0.34 | 1.25 | 27.2 | |||
p19 | 0.14 | 1.54 | 9.09 | |||
p20 | 0.17 | 0.25 | 68 | |||
p21 | 0.1 | 0.5 | 20 | |||
p22 | 0.14 | 0.25 | 56 | |||
p23 | 0.09 | 0.3 | 30 | |||
p24 | 0.05 | 1.33 | 3.75 | |||
p25 | 0.14 | 0.87 | 16.09 | |||
p26 | 0.2 | 1.2 | 16.6 | |||
p27 | 0.13 | 1.4 | 9.28 | |||
p28 | 0.28 | 1.11 | 25.22 | |||
p29 | 0.12 | 2.52 | 4.76 | |||
p30 | 0.08 | 0.6 | 13.3 | |||
p31 | 0.29 | 2.43 | 11.93 | |||
p32 | 0.3 | 1.5 | 20 | |||
p33 | 0.08 | 0.9 | 8.8 | |||
p34 | 0.3 | 1.14 | 26.31 | |||
p35 | 0.6 | 3.36 | 17.85 | |||
p36 | 0.35 | 0.48 | 72.91 | |||
p37 | 0.09 | 0.8 | 11.25 | |||
c1 | 0.057 | 0.095 | 60 | |||
c2 | 0.027 | 0.09 | 30 | |||
c3 | 0.048 | 0.096 | 50 | |||
c4 | 0.056 | 0.08 | 70 | |||
c5 | 0.026 | 0.34 | 7.64 | |||
c6 | 0.2 | 0.2 | 100 | |||
c7 | 0.07 | 0.093 | 75.26 | |||
c8 | 0.023 | 0.04 | 57.5 | |||
c9 | 0.029 | 0.029 | 100 | |||
c10 | 0.018 | 0.02 | 90 | |||
c11 | 0.075 | 0.075 | 100 | |||
c12 | 0.022 | 0.028 | 78.57 | |||
c13 | 0.033 | 0.88 | 3.75 | |||
c14 | 0.008 | 0.06 | 13.3 | |||
c15 | 0.036 | 0.072 | 50 | |||
c16 | 0.18 | 0.39 | 46.15 | |||
c17 | 0.21 | 0.21 | 100 | |||
c18 | 0.022 | 0.16 | 13.75 | |||
pm1 | 0.2 | 0.6 | 33.3 | |||
m1 | 0.23 | 2.08 | 11.05 | |||
m2 | 0.34 | 0.64 | 53.12 | |||
m3 | 0.19 | 1.12 | 16.96 | |||
m4 | 0.27 | 1.88 | 14.36 |
The scleractinian communities (Fig. 18) in the Dardanelles form mainly separate colonies, bank-type structures and solitary assemblages. Despite the strait’s characteristics which mostly reflect the combined characteristics of the waters in the Mediterranean Sea, the Black Sea and the Sea of Marmara, the species adapted to the specific conditions that occur in the range of habitats associated with rocky overhangs, ceilings, coralligenous, calcareous bio-concretions, sponge-dominated localities and seaweed roots, some of which are widely distributed around the shaded parts of hard substrates and amidst the beds of
Additionally, the fact that the Mediterranean-originated colonial corals and several solitary individuals were discovered in the Marmara Sea draws attention with respect to the species’ distributional behavior. The species extend their distributional limits in the Aegean Sea (Çinar et al. 2014) to the northern part of the Marmara Sea. Although there were no reports regarding the scleractinians in the Dardanelles and the surrounding seas, the investigations showed that the coral colonies and solitary species in the strait have older facies, well-developed on the rocky substrate and thus occurring for years, especially around the calcareous bioherms. In terms of ecosystem differences, many well-structured and complex hard coral assemblages can be observed in other strait habitats worldwide (Loya 2004; Cairns 2004; Álvarez-Perez et al. 2005; Riegl et al. 2012). Some coral surveys were successfully carried out for nearly 35 years in the Red Sea, in the Strait of Bap el Mandeb and around their coastal waters aiming at species’ sustainability (Rosenberg & Loya 2004). In other studies concerning the same issue, the water characteristics and light were regarded as the most important factors for the distribution of scleractinians in the strait of Gibraltar (Álvarez-Perez et al. 2005).
It has been found, in a detailed manner, that the Dardanelles is strongly influenced by saline waters after nearly 12 m and salinity continues to increase with depth to deep levels (lower layer flow) with an average value of 38.67 PSU (Beşiktepe 2003, Baba et al. 2007, Artüz 2013). According to recent studies, the wide distribution of
In comparison, there was an extensive distribution of scleractinians in the Dardanelles, mainly below 15 m depth due to physical conditions similar to those discussed above. Morri et al. (2000) recorded
Since the new communities of coral species discovered after 2014 were excluded from the statistical analysis, they were represented by only one station (Station 2). Colonies of species from the deep waters of the Adriatic Sea were also reported by Kružić (2002). When comparing the habitat characteristics, it was also revealed that
Additionally, it was also found that the mean colony length (D1), measured on the basis of 74 colonies in the Dardanos region, showed a higher value (56.77±1.59 cm). The lower and upper limits, accepted as significantly important for the calcification of
In the current study, the temperature varied between 8 and 26°C in the Dardanelles. There was one colony of
At some locations, corallites of
Among the solitary corals,
Also
Consequently, the highest calix length in the current study was determined as 24 mm. Comparing the data from the Dardanelles to the other studies presented above, it appears that the species’ dimensions are similar despite lower salinity levels in the strait.
Despite all the efforts spent on diving surveys and measurements aimed at carrying out the first detailed scleractinian research on the Turkish coasts, we believe that there may be more species to be found attached to dimly-lit cryptic localities of rocky habitats and coralligenous formations at deep waters in the Dardanelles. All species surveyed within the current study (Table 5) were the Mediterranean-originated corals. It is interesting that species (
List of scleractinian corals from the Turkish coasts with the updated distributional data
Species |
BS |
M |
AE |
MS |
D |
Habitat |
DR |
---|---|---|---|---|---|---|---|
Phylum: Cnidaria | |||||||
Class: Anthozoa | |||||||
Family: Pocilloporidae | |||||||
Heller, 1868; |
- | FL1 | FL2 | - | FL3-PR | H | VII |
Family: Faviidae | |||||||
Linnaeus, 1767; |
- | FL4 | FL5-PR | - | FL6-PR | H | II |
Family: Caryophylliidae | |||||||
Stokes & Broderip, 1828; |
- | FL7 | FL7* | FL8-PR | FL10-PR | H | IV |
Ellis and Solander, 1786; |
- | - | - | FL23 | - | H | 70-300 m** |
Milne-Edwards and Haime, 1848; |
- | - | - | FL10 | - | H | 65-250 m** |
Gosse, 1860; |
- | - | FL22 | - | - | H | 0-150 m** |
Duncan, 1878; |
- | FL11 | FL12 | - | PR | H | IX |
Philippi, 1842; |
- | - | - | FL13 | PR | H | VIII |
Abel, 1959; |
- | FL14 | FL15 | PR | PR | H,S | V |
Lacaze-Duthiers, 1897; |
- | FL16 | FL17 | - | PR | H | III |
Esper, 1794; |
- | - | - | FL24 | - | H | 8-2460 m** |
Family: Dendrophylliidae | |||||||
Risso, 1826; |
- | FL18 | FL19 | - | FL19-PR | H,R | I |
Lacaze-Duthiers, 1897; |
- | FL21 | FL22* | - | PR | H | VI |
Linnaeus, 1758; |
- | - | - | FL10 | - | H | 40-150 m** |
De Angelis, 1908; |
- | FL25 | - | - | - | H | 0-10 m** |
BS: Black Sea; M: Mediterranean Sea; AE: Aegean Sea; MS: Marmara Sea; D: Dardanelles (Çanakkale Strait); DR: Depth range in the current study; H: hard substrate; S: soft substrate; R: Posidonia oceanica roots; PR: Present research; Authors:
I: 0-23 m; II: 2- 23 m; III: 18-19 m; IV: 12-44 m; V: 15-44 m; VI : 17-44 m; VII: 20-39 m; VIII: 20-43 m; IX: 25-40 The first and the latest report of scleractinian coral from the Turkish coasts: FL1: Zibrowius 1979; FL2: Forbes 1844/Gökalp 2011; FL3: Özalp and Alparslan 2015; FL4: Özturk et al. 2004/Özturk et al. 2013; FL5: Forbes 1844/PR; FL6: Özalp and Alparslan 2011/PR; FL7: Özturk et al. 2004/Gönülal and Güreşen 2014*; FL8: Özturk et al. 2004; FL9: Ostroumoff 1896/PR; FL10: Ostroumoff 1896/PR; FL11: Gözcelioglu 2011; FL12: Zibrowius 1979; FL13: Demir 1952; FL14: Çinar et al. 2015; FL15: Zibrowius 1979a/Gökalp 2011; FL16: Zibrowius 1980**/Bitar and Zibrowius 1997; FL17: Zibrowius 1980/Gökalp 2012; FL18: Gözcelioğlu 2011; FL19: Zibrowius 1979/PS; FL20: Ostroumoff 1896/PR; FL21: Gözcelioğlu 2011; FL22: Gökalp 2011/ Gönülal and Güreşen 2014*; FL23: Colombo 1885; FL24: Taviani et al. 2011; FL25: Çinar et al. 2006.
Although some of the projects on monitoring and conservation biology were successfully implemented for the strait’s communities, the general information about their population dynamics still needs to be increased.
We are very thankful to Harun Kiran, Kamil Emre Bariş, Ünal Asimoğlu, Malik Selek and Oğuzhan Naldöken for their great effort during the field surveys carried out in 200 stations. We also would like to express our gratitude towards Dr. Melih Ertan Çinar, Dr. Andrea Peirano, Dr. Helmut Zibrowius, Dr. Carla Morri, Dr. Petar KruŽić, Dr. Stephen C. Cairns, Dr. Stefano Goffredo and Dr. Erik Caroselli for their valuable suggestions, guidance and patience to our unceasing emails.
Although this is the first detailed investigation on Scleractinian Anthozoans of the Turkish coasts ever made, every stage of this marine research has been conducted with huge personal support and unfortunately without any national funds or contribution of any project. Thus, as the first author of this strenuous work, I feel myself very obliged to my wife Simge Ozalp for everything.