ACTA ZOOLOGICA BULGARICA Applied Zoology Acta zool. bulg., 70 (2), 2018: 259-268 Research Article Deep Sea Fisheries in Mersin Bay, Turkey, Eastern Mediterranean: Diversity and Abundance of Shrimps and Benthic Fish Fauna Yusuf Kenan Bayhan 1* , Deniz Ergüden 2 & Joan E. Cartes 3 1Fisheries Department, Kahta Vocational School, Adiyaman University, 02400, Kahta, Adiyaman, Turkey; E-mail: [email protected] 2Marine Science and Technology Faculty, Iskenderun Technical University, 31220, Iskenderun-Hatay, Turkey; E-mail: [email protected] 3ICM-CSIC Institut de Ciencies del Mar, Passeig Maritim de la Barceloneta 3-49, 08003 Barcelona, Spain; E-mail: [email protected] Abstract: This study was carried out by trawling at depths between 300-601 m in the Mersin Bay (Eastern Mediter - ranean) between May and June 2014. Seven shrimp species ( Aristaeomorpha foliacea , Aristeus antenna - tus , Parapenaeus longirostris , Plesionika edwardsii , Plesionika martia , Pasiphae sivado and Pontocaris lacazei ) were collected as a result of ten trawl operations with a commercial bottom trawl. The most abundant species were P. longirostris (52.06%), A. foliacea (35.64%) and P. edwardsii (9.50%), represent - ing 97.20% of all captured shrimps. The catch per unit eort (CPUE) ranged from 3.094 kg/h to 9.251 kg/h, with an average value of 5.44 ± 2.01 kg/h for shrimps. A total of 37 sh species (28 teleosts and nine elasmobranchs) were captured. The prevailing sh species in catches were Chlorophthalmus agassizi , Merluccius merluccius and Etmopterus spinax in terms of biomass and Helicolenus dactylopterus , Hoplo - stethus mediterraneus , Trachurus trachurus and Lepidopus caudatus in terms of abundance. Seventeen or 45.95% of the captured sh species were with commercial value, while the remaining 20 (54.05%) consisted of discard shes. Keywords: Deep-sea shery, Decapoda, Crustacea, benthic sh fauna, Eastern Mediterranean Introduction The Mediterranean Sea has a rich diversity of spe - arriving by several spread routes ( B et cies, incorporating more than 1,500 mollusc, 1,000 al . 2014, E et al. 2016). arthropods (only of Crustacea and Pycnogonida) Although there have been many studies on the and 650 sh species ( Q T 2000, identication of bio-ecological characteristics and P L 2008, C et al. 2010, deep-sea population structure in the Mediterranean, Öü et al. 2014, B et al. 2014, B there are limited numbers of studies on the compo - et al. 2014). Recent studies by B et al. sition, diversity, sh abundance and especially size (2014) and E et al. (2016) found a current distribution of the deep-sea species in the Eastern total of 517 sh species in Turkish marine waters: Mediterranean, Turkey ( A 1993, Bş 451 of Osteicthyes, 64 of Chondricthyes, one of 1997, B et al. 1999, C Aş 2005, C et Cephalospidomorphi and one of Holocephali. Some al. 2006, Göü et al. 2010, Yşç Kş 447 species of those sh species are distributed along 2011, D 2012, Yş et al. 2014). Turkey Mediterranean coasts. To date, the number of Large amounts of species in aquatic ecosystems reported sh species is increasing with alien species in the Mediterranean Sea are captured with deep *Corresponding author: [email protected] 259 Bayhan Y. K., D. Ergüden & J. E. Cartes trawl nets, mainly above the slope of the continental shelf. As in all the world’s oceans, overshing from the continental shelf in the Mediterranean Sea has led to the need of commercial exploitation of resources living in deeper waters and in more distant regions. However, one of the most important factors limit - ing deep-sea shing in the Eastern Mediterranean is the obligation of greater capacity (length and engine power of the boats and requirements for specic equipment); shing in deep water is hard, laborious and expensive. According to the latest obtained re - Fig. 1. Map indicating the study area. cords, there are 185 bottom trawlers in the Turkish Eastern Mediterranean ( A 2014). The Σ tn = duration of hauling number of boats with permission for shing in in - For the calculation of the swept-trawled area in ternational waters (12 miles and above) outside the the hauling legal shing period is 64 ( A 2014) and (a)= D x h x X 2 equality was used, only 15 of them have been shing in deep water (200 where m and above) in the 2014-2015 shing season. a – trawled area swept by the trawl net; In order to improve the management of marine D – length of the trawled area. living resources at a sustainable level, their species For the precise measurement the geographic diversity and abundances must be known. Therefore, coordinates from the GPS of the boat were con - the aims of this studies are: determination of sher - verted to degrees and transferred to UTM (Universal ies abundance, deep-water species composition of Transverse Mercator) coordinate system with Netcad shrimp and benthic sh fauna, their incidence and program; and the distance between the start and end size distribution of shrimp species living in the deep points for each hauling was calculated. sea for the rst time in international waters of the H – length of the oatlineof the trawl net (23 m). Mersin Bay, Eastern Mediterranean, Turkey. X2 – opening ratio of the oatline was taken as 0.5 according to ( P 1980). After each hauling, shes were selected ac - Materials and Methods cording to their species and the total weight of shes Our sampling was carried out on 17 May 2014 in large amounts and lengths of the units separated and 25-27 June 2014 at Mersin Bay (Eastern by sub-sampling method. The number and size of Mediterranean, Turkey) in international waters rang - the shes in small amounts were separately placed in ing between 12.7–35.9 nautical miles from the coast plastic boxes. Fish samples were taken to the Kahta and at water depths between 300 and 601 m. Towing Vocational School laboratory. After the taxonomic was carried out with the commercial trawler “Çınar analyses, the total length and weight of each speci - Bey” (length 26.15 m and engine power 480 hp), men were measured with ± 0.01mm and 0.1 g preci - equipped with a two-warp bottom trawl net. This sion, respectively. All the meristic characters were type of net is legally specied for the Mediterranean recorded through microscopic inspection; Olympus and has a 44 mm mesh cod-end and PE material was SZ61 microscope was used for the determination of used. The average towing speed was 2.4 knots, the meristic values. Species determination was accom - trawl operation lasted a total of 53 h and 10 min and plished by specialized keys ( W et al. 1989, the total trawled area was 2,85 km 2. The coordinates N 2006, E 2016). and depths were measured by satellite GPS and The coordinates, depths, hauling time and dura - echo sounder on the boat, respectively. After every tion of the trawl operation are given in Table 1 and hauling the weight of the shrimps which were over - the shery region of the study is shown in Figure 1. weight were measured using digital scales (± 0.1 g) on board and the lightweight shrimps were measured on 0.001 gram precision digital scales in the labora - Results tory. The catch per unit eort (CPUE) values was As a result of ten trawl operations, seven calculated according to the following formula: shrimp species were captured. These included CPUE = ∑Wn / ∑ tn Aristaeomorpha foliacea and Aristeus antennatus ∑Wn = total weight of samples captured in the of the family Aristeidae, Parapenaeus longirostris nth hauling time for type a of the family Penaeidae, Plesionika edwardsii and 260 Deep Sea Fisheries in Mersin Bay, Turkey, Eastern Mediterranean: Diversity and Abundance... Table 1. Coordinates, depth, time and duration of hauling in the trawl operations. Coordinates Depth Total Trawling time Average Hauling (N/E) (m) trawling speed number time Da t e nished (knot/h) start nished start nished start (minutes) 36 0 18 ’ 283 ’’ / 36 0 12 ’ 606 ’’ / 410 411 1st 04 55 am 10 00 am 305 2.4 34 0 26 ’ 134 ’’ 34 0 39 ’ 903 ’’ 17.3* 29.7* 36 0 13 ’ 100 ’’ / 36 0 18 ’ 831 ’’ / 399 415 2nd 10 55 am 16 00 pm 305 2.4 34 0 38 ’ 570 ’’ 34 0 25 ’ 760 ’’ 27.0* 16.2* 2014 17 May 36 0 15 ’ 295 ’’ / 36 0 23 ’ 196 ’’ / 522 446 3rd 18 15 pm 22 30 pm 255 2.4 34 0 19’ 806 ’’ 34 0 26 ’ 713 ’’ 12.7* 14.3* 36 0 23 ’ 938 ’’ / 36 0 12 ’ 187 ’’ / 300 542 4th 05 05 am 10 00 am 295 2.4 34 0 28 ’ 532 ’’ 34 0 33 ’ 780 ’’ 15.2* 25.4* 0 ’ ’’ 0 ’ ’’ th 36 12 253 / 36 11 095 / 513 349 50 40 5 0 ’ ’’ 0 ’ ’’ 10 am 15 pm 290 2.4 2014 34 33 986 34 48 085 25.9* 34.6* 25 June 36 0 11 ’ 196 ’’ / 36 0 14 ’ 754 ’’ / 388 386 6th 16 30 pm 20 40 pm 250 2.4 34 0 46 ’ 990 ’’ 34 0 35 ’ 375 ’’ 34.0* 25.4* 36 0 14 ’ 061 ’’ / 36 0 10 ’ 402 ’’ / 377 364 7th 05 40 am 10 05 am 265 2.4 34 0 37 ’ 002 ’’ 34 0 49 ’ 538 ’’ 26.7* 35.9* 0 ’ ’’ 0 ’ ’’ 2014 th 36 08 604 / 36 17 766 / 582 459 15 00 26 June 8 12 pm 20 pm 465 2.4 34 0 38 ’ 593 ’’ 34 0 22 ’ 533 ’’ 30.5* 14.6* 36 0 16 ’ 417 ’’ / 36 0 09 ’ 041 ’’ / 601 557 9th 05 20 am 12 05 pm 405 2.4 34 0 22 ’ 132 ’’ 34 0 35 ’ 851 ’’ 15.4* 28.0* 0 ’ ’’ 0 ’ ’’ 2014 th 36 09 478 / 36 15 501 / 555 593 05 00 27 June 10 13 pm 19 pm 355 2.4 34 0 33 ’ 900 ’’ 34 0 21 ’ 292 ’’ 26.0* 16.2* 3190 (53 hr and 10 Total trawling time min) (*) Distances from the coast (nautical miles) P.