By-catch in the commercial beam trawl fishery for Rapa Whelk in the Black Sea

In this work, the by-catch was investigated in commercial beam trawls used in the rapa whelk (Rapana venosa) fishery, in trials at sea between September 1, 2015 and April 30, 2016. Four commercial boats using beam trawls were chartered and catch data was collected from a total of 87 hauls. Hauls were performed between 7.1–28.3 meters deep for a duration of 20–77 minutes and haul speed varied between 1.4 – 2.7 knots. A total of 28 by-catch species were identified, which amount in average to 11.4% of the total number of specimens in the by-catch. Two different groups were identified in the by-catch (G1: 7-18 m, G2: 19-26 m) according to depth. Although there is a reduction in the amount of by-catch for G2 group, no significant difference was found between groups (p>0.05). According to Generalized Additive Models (GAM) results, the variables affecting the by-catch amount were identified as fishing area, depth, haul duration, and amount of captured rapa whelk (p<0.01). In addition, a large proportion of immature individuals of striped venus clams (Chamelea gallina), blood cockles (Anadara kagoshimensis), Mediterranean mussels (Mytilus galloprovincialis) and wedge clams (Donax trunculus) were caught as by-catch during the study. Finally, the impact of commercial beam trawls on the demersal macrofauna is discussed

A PRELIMINARY STUDY ON WHITING (MERLANGIUS MERLANGUS) BEHAVIOUR TO BOTTOM-SET POT IN THE BLACK SEA

WOS: 000449141700054Due to overfishing and decreasing in fish stocks, interactions between dolphins and deep gill nets have increased rapidly in recent years for the Black Sea. Dolphin-inflicted damage to fishing gear and catch losses have increased along the Black Sea coast of the Turkey and many small-scale coastal fishermen have been severely affected. the bottom set Norwegian two-chamber pot was tested as alternative to deep gill net for preventing dolphin damage and catch losses for whiting (Merlangius merlangus) fisheries in the Black Sea and catch efficiency was found to be very low. in this study, underwater video analyses were made to describe the behaviour of whiting in and around bottom-set Norwegian two chamber pot to determine factors that are related to the catch efficiency. A total of successful 8 deployments were carried out between July 2016 and March 2017 within the boundaries of Rize province (south-eastern Black Sea). Pot was deployed at depths of 55-75 m and a total of 51 hours' video records were obtained by GoPro Hero 4 and Sony action cameras. Results showed that the 98% of observed whiting individuals approached the pot from upstream direction. in addition, it was observed that all of entering the pot occurred from upstream direction. Finally, pots should have a number of entrances to ensure that one of the entrances stays in line with the downstream and the entrances should not be placed in such a way they face each other for improving capture efficiency of whiting.Recep Tayyip Erdogan University Research Project FundRecep Tayyip Erdogan University [FBA-2016-546]I would like to thank the captain and crews of the Piryoz 53 and Karadeniz Research Vessel. Thanks are also extended to Mehmet Saban Kutay and Yusuf Ceylan for their help in the sea trials. This study was financed Recep Tayyip Erdogan University Research Project Fund (Project No: FBA-2016-546)

EFFECTS OF SQUARE-MESH CODEND ON THE BENTHIC BY-CATCH FOR THE BEAM TRAWL FISHERIES OF VEINED RAPA WHELK, RAPANA VENOSA

WOS: 000438656900006Background. the beam trawl fisheries of veined rapa whelk, Rapana venosa (Valenciennes, 1846), cause small benthic organisms to be captured and also damage the other species living on the seafloor. To solve this problem, a proper modification that minimise the by-catch should be designed and put into practice. This study aims to compare 72 mm commercial diamond-mesh codend with 72 mm square-mesh codend to reduce the benthic bycatch in this fishery. Materials and methods. Totally 15 hauls were carried out in south-eastern Black Sea Region within 10-14 August 2017. A commercial diamond-mesh and square-mesh beam trawls were towed simultaneously behind a commercial fishing vessel to compare the by-catch compositions. Paired t-test was used to compare the catch amount of two codends based on species. GLMM (Generalised Linear Mixed Models) was used to compare the length of captured veined rapa whelk, mussel, and crab species. Results. There was a 77-percentage-point reduction in the mean number of the captured individuals as by-catch in square-mesh codend when compared with commercial diamond-mesh codend and this difference was found statistically significant (P < 0.05). A total of 17 species was captured as by-catch in both codends. Comparing to diamond-mesh codend, the catch amount of the 13 by-catch species had decreased in square-mesh codend. Conclusions. in conclusion, the square-mesh codend was found successful in decreasing the by-catch amount of many benthic species except for flatfish species and large crabs. in addition to this, the veined rapa whelk amount fell by half and this means a 25-percentage-point profit decrease for fishermen.Recep Tayyip Erdogan University Research Project FundRecep Tayyip Erdogan University [FBA-2017-781]I would like to thank the captains and crews of the FV Piryoz 53. Thanks are also extended to Dr Goktug Dalgic and Yusuf Ceylan for their help in the sea trials. This study was financed by the Recep Tayyip Erdogan University Research Project Fund (Project No: FBA-2017-781)

Microplastic pollution profile of Mediterranean mussels (Mytilus galloprovincialis) collected along the Turkish coasts

Gedik, Kenan/0000-0001-8244-6935WOS: 000575197000054PubMed: 32668364Plastics profoundly threatens ecological balance in marine ecosystems across the globe in the current era of industrialization. Microplastics (MP), in particular, can pose risks reaching humans through the food web via various marine organisms. Among these organisms, since they are consumed as a whole, mussels are vital vectors of MP transfer during human consumption. Hence, here we analyzed MP pollution in Mediterranean mussel (Mytilus galloprovincialis) sampled from 23 different locations all along the Turkish coasts of the Black Sea, Sea of Marmara, and the Aegean Sea. After digestion of the mussels with H2O2, the micro-particles were determined under a stereomicroscope and characterized by confirming with FTIR analyses. 48% of the sampled mussels were found to have MPs. the average MP abundance was 0.69 item/mussel and 0.23 item/g fresh weight (fw) of soft tissue. Morphology was ordered as follows: fragments (67.6%)> fibers (28.4%)> films (4.05%). the dominant size of MPs was detected less than 0.5 mm (26.58%). 12 different polymers have been identified by FTIR and PET (32.9%), PP (28.4%), and PE (19.4%) were found to constitute 80% of the total MPs. the annual average exposure amount for mussel consumers in Turkey was estimated as 1918 MPs item/per year. Even though international organizations such as FAO, JECFA, or EU have not declared permissible limits, our data may inform human health uptake of MP ingestion via mussels. This data might also serve as a reference data-set for further MP monitoring research in Turkish and European Seas. (C) 2020 Elsevier Ltd. All rights reserved.Research Fund of the Recep Tayyip Erdogan University [FBA-2020-1094, FYL-2019-1033]This work was supported by the Research Fund of the Recep Tayyip Erdogan University (grant numbers: FBA-2020-1094 and FYL-2019-1033). We would like to express our gratitude to Erdinc Turanli for his precious support for mussel sampling. Also, we thank Necla Pehlivan for her language edit

Gasometer with the function of gas purification for the biogas systems in the rural AREA

WOS: 000297087600015In small farms in which biogas consumption is not continual, there occurs problem with the storage of the produced biogas. Because of its nature, biogas cannot be stored in middle or high pressure without purification. For this reason, floating dome type or balloon type low pressure gas storage systems are used. The reason why biogas systems are not common in the rural area is that floating dome gas storage systems have movable parts and that the materials used in balloon type systems are not durable and safe. In this study, performance tests were executed by preparing a safe system having no movable parts and easy to use. The gasometer in question provides the operating pressure that the devices need in order to operate without the help of another pressurizer by the principle of transposition of water. The acquired pressure values of 20-30 kPa enable biogas to be carried more than 100 m away with low costs. Maintenance cost is low because it does not have movable parts. It is safer against pressure increase because it is open to the atmosphere. Furthermore, because CO2 and H2S dissolve more than CH4 in water it was seen that the said gasometer could be used to purification biogas. In the tests 25-30 % CO2 removal and 98-100 % H2S removal was observed. This gasometer called "Gasometer with the function of gas purification for biogas facilities" numbered "TR 2006" was taken under protection and the simplicity, the functionality and safety increase the possibility of its usage in biogas systems in the rural area

An experimental study on steel-encased buckling-restrained brace hysteretic dampers

This paper describes a seismic test program performed on 12 steel-encased buckling-restrained braces (BRBs). The use of rolled or built-up buckling-restraining mechanisms with welded or bolted attachments was examined. In addition, the effects of bolt pretension, core-to-encasing attachment details, aspect ratio of core segment and imperfections due to manufacturing on the brace response were investigated. All specimens were subjected to a stepwise incremental quasi-static testing protocol with a maximum axial strain amplitude of 2%. All specimens except one showed satisfactory performance with stable hysteretic response and sustained cumulative inelastic deformations in excess of 200 times the yield deformation. Based on the experimental results, the compression strength adjustment factor, and the strain hardening adjustment factor for each excursion were quantified. Test results revealed that these two factors are significantly influenced by the parameters investigated in the experimental program. BRB details were also found to influence the buckling and the yielding patterns of the core segment. Copyright (C) 2009 John Wiley & Sons, Ltd

Determination of thermal performance of a solar collector by using dynamic test method

WOS: 000483365300006In Turkey at the location where solar energy is rich, liquid-glazed type flat plate solar collectors have been widely used to obtain domestic hot water for many years. However, it is generally faced some products which do not fulfill the requirements of the final consumers and have low thermal efficiencies since this type of collectors are easily manufactured. In order to prevent from this issue, it is needed to do thermal performance tests of the solar collectors. The thermal performance tests are performed under the steady state and dynamic operating conditions. In this study, thermal performance of a liquid based (water), glazed (glass) type solar collector is determined under the dynamic operating conditions. For this purpose, thermal equation of the collector is developed, and an experimental setup is installed. Experiments are performed for four different inlet temperatures (25 degrees C, 30 degrees C, 45 degrees C, 60 C) and constant mass flow rate (0.037 kg/s) at outdoor conditions. Constants in the equation are solved by Multiple Regression (MLR) method. Results of the experimental study and thermal equation show that a fairly similar characterization is obtained