COMU Journal of Marine Sciences and Fisheries

109-118

Authors: Abdolsaleh QARANJIKI, Mine KIRKAĞAÇ

In this study, Artemia parthenogenetica was fed with either Spirulina (S), yeast (Y), rice bran (R), oat (O) or their combinations in 10 experimental groups in triplicate for 20 days in laboratory conditions and growth, biomass, feed conversion rate (FCR), specific growth rate (SGR), survival rate, crude protein, crude lipid contents were determined. The highest average body length obtained at the end of the experiment was 2.805±0.003 mm in treatments (S) and (SYR), and the highest average individual dry weight was 23.057 µg in treatment (S). The mean biomass changed between 167.2±0.003 mg and 115.7±0.012 mg. The highest biomass value was 20.9 g/m3 in treatment (S), followed by 20.5 g/m3 in treatment (SYR). The highest FCR was found to be similar in (S) and (Y) with 1.14±0.02. SGR was 1.01±0.001 in all experimental groups. The highest survival rate was in treatment (S), and overall it ranged between 78.22±1.78 - 90.64±0.06%. The highest crude protein contents of Artemia were found in (SR) and (S) and the highest lipid content was found in treatment (O). As a result, it is thought that combinations of by-products such as rice bran and yeast together with microalgae will be economical in the cultivation of Artemia parthenogenetica.

143-149

Authors: Herdem ASLAN

The demand for the roe of Paracentrotus lividus is increasing despite world-wide fisheries bans and the balance of marine ecosystems is disturbed due to this overexploitation. Although not consumed locally, there has been fishing pressure on this species, due to the intense export demand in recent years. For an ecosystem-based sustainable fishery of P. lividus, it is very important to establish the stock status as well as the reproductive biology of this species in Turkish seas. However, studies on the stock information of the species are limited. This study reports preliminary findings on the abundance of P. lividus on the coasts of Gökçeada by using the visual counting technique with SCUBA during the summer of 2012 and 2018. In the study carried out with transects of different lengths, the highest number of individuals was observed on the rocky shores of Laz Bay in 2012 with 4 individuals m-2, between 112-120 m of the Kuzulimanı transect with 5 individuals m-2 in 2018, and between 0-52 m transect of Kokina III in 2018. According to the SACFOR scale, when P. lividus species was observed on the coasts of Gökçeada, it was either common or frequent in terms of abundant. For an effective and sustainable sea urchin management plan, the stock status of the P. lividus species in Turkish waters should be determined immediately.

160-168

Authors: Burhan TAŞLI, Adnan AYAZ

As in every business sector, the safety factor in fishing is too important to ignore. Although there is no deficiencies of equipment and materials in fishing boats, we can say that if the safety issue is not internalized by the employees, the danger continues. In addition, the idea that the safety at sea can only be provided by the equipment on the boat remains missing. Especially the fishermen's ignorance of the navigation restrictions and difficulties in the fishery areas causes a serious danger. The Turkish Straits, which is our field of study, is also the most dangerous and heavily trafficked strait in the world. For this reason, fishermen must be aware of all meteorological, navigational and geographical restrictions. Semi-structured interviews were conducted with the fishermen who navigate the straits to reach the fishery area or use the straits as fishery grounds. As a result of the interview, it was aimed to determine the awareness of safety and navigational safety at sea. With 1 fisherman in Yeniköy Harbor, 1 fisherman in Kumkale Harbor, 2 fishermen in Gallipoli Harbor, 2 fishermen in Şarköy Harbor, 4 fishermen in Hoşköy Harbor, 5 fishermen in Çakılköy Harbor, 5 fishermen in Karşıyaka Harbor and 3 fishermen in Kurşunlu Harbor in Turkey, interviews were held a total of 23 fishermen. The interviews were audio recorded with the permission of the participants and analyzed by content analysis method. As a result of the analysis, it has been determined that the fishermen mostly ignore the safety factor and especially see the safety equipment as an expense item that creates a financial burden. It has been determined that navigational safety awareness is higher than safety awareness at sea. It has been observed that there are no lack of equipment possession, but it is generally equipped with survey reservations.

179-187

Authors: Soner ÇETİNKAYA

In this study, electrolyzed water (EW), which is being used for disinfection in various food production applications, is discussed. Today, research on green production has intensified, aiming to preserve food for a longer time, using fewer chemicals or none, in order to preserve the initial nutritional properties of the food and deliver it to the consumer. In this context, it is an undeniable fact that there is a need to improve existing methods and practices and develop new technologies for the long-term storage of foods without quality losses and health concerns. One of the methods developed for this purpose is the use of electrolyzed water in food disinfection. While the use of electrolyzed water in various stages of the food processing industry creates a relatively new field of application, many studies have focused on its antimicrobial and antioxidant activity. However, studies on the use of this method in the fish processing industry are very limited and need to be developed. Previous studies are mainly related to the antimicrobial properties of electrolyzed water and there are limited studies on the effects of seafood products on storage times (shelf life). However, in light of the studies, it is seen that electrolyzed water has potential uses for the seafood processing industry.

199-202

Authors: Okan AKYOL, Halil ŞEN, Christian CAPAPÉ

In this study, a shoal of bull rays, Aetomylaeus bovinus (E. Geoffroy Saint-Hilaire, 1817), around a sea-cage fish farm in Iskenderun Bay, Turkey is reported. Such an aggregation is probably due to ontogenetic shift but may also be a factor of reproductive process as some pregnant females were observed. The number of individuals recorded, in all more than 25, shows that the species is still present in the area but needs a conservation plan due to its k-selected life-histories and potential for extinction.

11-18

Authors: Sevdan YILMAZ Ekrem Şanver ÇELİK Dilek KAHRAMAN YILMAZ Mehmet Ali KÜÇÜKER

In this study, cyanobacterial communities in mucilage samples collected from three stations in the Dardanelles Strait were analyzed with a metagenomic approach. Mucilage samples were collected at the beginning of June 2021 from three points of the Dardanelles (Station 1: 40°6'42.78"N, 26°23'57.00"E; Station 2: 40°9'8.09"N, 26°24'16.19"E; Station 3: 40°6 '21.62"N, 26°22'41.25"E). The dominant cyanobacteria were Prochlorococcus marinus (39.17%), Synechococcus sp. (20.85%), Lyngbya sp. (12.00%), Trichodesmium erythraeum (7.33%), Aphanocapsa sp. (4.33%) and Leptolyngbya sp. (3.33%), which constituted 87.00 % of the total number of sequences. In this study, cyanobacteria species that can cause harmful algal blooms and have toxic effects on the mucilage structure have been determined. The Marmara Sea and the Dardanelles Strait, which have been affected by serious disturbances, including industrial activities, anthropogenic impacts, tourism and artificial lighting, will never be fully restored to their former ecological state. In addition, cyanobacteria species in the mucilage may cause harmful algal blooms and have toxic effects that threaten the future well-being of coastal populations and ecosystem stability. Thus, the government and local authorities should pay more attention to combating the mucilage.

26-38

Authors: Deniz Anıl ODABAŞI Serpil ODABAŞI Ozan DENİZ Fikret ÇAKIR Belgin ÇAMUR ELİPEK Naime ARSLAN Onur ÖZBEK H. Barış ÖZALP

Caves are laboratories for many disciplines that work in natural sciences including mineralogy, biology, hydrogeology, and archaeology. In this study, bi-monthly samplings were carried out from three sampling locations within and around the Güvercinkaya Cave, a high-altitude cave located in northwestern Turkey, to evaluate the hydrochemical and microbiological properties and the aquatic macroinvertebrates of the cave stream. Some parameters of the water including pH, electrical conductivity, temperature, oxidation-reduction potential, and dissolved oxygen were measured in-situ, while elemental (70 in total) and ionic composition of water were analyzed in the laboratory. Microbiological analyses of the cave stream were examined through analyses of total bacteria, total coliforms, fecal coliforms, fecal Streptococcus, and Escherichia coli. According to the Piper diagram of hydrochemical data, the cave stream had mainly Ca-Mg-HCO3 character, on the other hand, the Schoeller diagram indicated a common water source in Güvercinkaya cave due to the similar components of the main ionic components of the water. As a result of microbiological analysis, fecal contamination was determined, indicating active wildlife in the cave. Additionally, several aquatic macroinvertebrates taxa, Rhynchelmis limosella, Dugesia sp., Gammarus uludagi which have non-troglobiont character were found in the cave stream. Rhynchelmis limosella detected in this study is the first record for the Turkish fauna.

48-55

Authors: Erhan MUTLU Yaşar ÖZVAROL

The present study reports the occurrence of Oceania armata in the Turkish Levantine Sea, and presents evidence to support a hypothesis established to link an increased recent and near-past records of many gelatinous zooplankton species in the Turkish seas, and particularly in the Turkish Levantine Sea to specific Mediterranean basin-scale currents (Atlantic-Ionian Stream and the Mid-Ionian Jet). One worldwide-distributed oceanic cnidarian specimen was collected from the surface water of a location of 36.59002 N and 29.02471 E by a SCUBA diver on January 18, 2019 in the eastern Mediterranean Sea. The hydrozoan specimen was then identified as O. armata and recorded for the first time in the Turkish Mediterranean coast and only second time in the Levant coast after about 30 years. This is the second report of the species from the Turkish waters, and the first report was from the Turkish Aegean coast. Recently, new records of the gelatinous species have increased from the Turkish marine coasts; Sea of Marmara, Aegean Sea, and Levantine Sea. Most of them are distributed in the West Mediterranean Sea, but are also present in the Adriatic Sea (East Mediterranean Sea). In the Mediterranean Sea, one branch of the Atlantic current (Atlantic-Ionian Stream) enters the eastern basin via the Mid-Ionian Jet, linked with the southern Adriatic current. Therefore, it is possible that zooplankton could have entered East Mediterranean by the Atlantic current through West Mediterranean.

67-76

Authors: Tekin DEMİRKIRAN Uğur ÖZEKİNCİ

This study was aimed to determine the effects of different bait types on the efficiency of fyke-nets and traps in catching narrow-clawed crayfish (Pontastacus leptodactylus (Eschscholtz, 1823)). The study was carried out in Atikhisar reservoir, Çanakkale, between July 2020 and March 2021. In the study, 12 traditional fyke-nets (“D” inlet, 5 rigid rings and a leader net) and 12 traps (double inlet) were used. Fyke-nets and traps were rigged with 34 mm stretched mesh that are commonly used in crayfish fishing in Türkiye. Three different bait types including fish, chicken and bread and a control treatment with no bait were allocated to each gear type. Baits were distributed randomly to each gear before fishing trials. The baits were placed in small bags corresponding to 1% of total trap volume. The results of 24 trials showed 68.8% (1940 crayfish) of the total catch was caught with fyke nets and 31.20% (880 crayfish) with traps. The highest average CPUEN values for both trap types were observed in those baited with the chicken meat which were 7.89±1.02 n/fyke net/day and 5.07±0.88 n/trap/day.. The mean length of the crayfish caught by the fyke nets was significantly smaller than those caught by the traps (p<0.05). When the mean CPUE values based on the number of fishing operations were compared, differences were significant for baits other than the chicken meat (p<0.05). These results showed that catching efficiencies of baited fyke-nets and traps were higher (especially chicken meat) than those of unbaited traps than those without bait.

87-93

Authors: Okan AKYOL Tevfik CEYHAN Faik Ozan DÜZBASTILAR Okan ERTOSLUK

This study presents some exotic fish diversity and catch per unit effort values of exotic fish from gillnet fishery along the southern Aegean Sea. Lessepsian puffer fish (Lagocephalus sceleratus), lionfish (Pterois miles), squirrelfish (Sargocentron rubrum), rabbitfish (Siganus sp.) and a blue crab (Portunus segnis) were caught in the Aegean Sea. Rabbitfish and blue crab sell in the fish markets. Seasonally, the average CPUE of exotic fish was calculated to be 0.7 ± 0.3 kg.1000 m-1 in autumn in catch. This value indicated that it was 72 times lesser than the total seasonal CPUE.

98-102

Authors: Seçil ACAR Yusuf ŞEN

Some morphometric and biological characteristics of a European spider crab, Maja squinado (Herbst, 1788) caught off Aksaz region, (Biga, Çanakkale, Türkiye) were investigated. In addition, an epizoic species infesting this M. squinado specimen has been identified. The crab specimen was caught by a commercial fisherman using trammel nets. Carapace length, carapace width and weight of the crab were 15.9 cm, 14.5 cm, and 1109 g respectively. The specimen was an ovigerous female with a calculated fecundity of 3.48x104 eggs. Eggs were in stage 4th of development and covered the whole carapace region. Additionaly, it was observed that the specimen was infested with the epixoic barnacle Octolasmis angulata (Aurivillius, 1894). A total of 46 O. angulata individuals were observed; 32 from the gill lamellae, and 14 from the carapace. This study reports the existence of the epizoic O. angulata on Maja squinado for the first time in Türkiye.