Acta Nat. Sci.   |  e-ISSN: 2718-0638

Volume 2 Issue 2 (December 2021)

Issue Information

Issue Full File (2021-Volume 2, Issue 2)

pp. i - vi   |  DOI: 10.29329/actanatsci.2021.350


2021-Volume 2, Issue 2

Issue Full File

Cover, Editorial Board, Indexing, Table of Contents


Original Articles

Does Maritime Transport Network Converge? Evidence From EU Countries

Abdullah Açık

pp. 86 - 93   |  DOI: 10.29329/actanatsci.2021.350.01


The concept of convergence is an important issue that has gained a wide place in the economics literature. The convergence of economies is likely to have an impact on the transportation sector as well, since it is the most important supporter of economic activities, and it is directly affected by economic indicators due to its derived demand structure. However, the possible reflections of economic convergence in the transportation sector have not received sufficient attention in the literature. In this study, we investigated this issue in the European Union (EU) countries, where economic convergence is implemented as a union policy and the existence of convergence is empirically supported in many studies. We select Liner Shipping Connectivity Index (LSCI) as a variable, which indicates the countries’ level of connectivity in the liner transportation network mostly used to transport intermediate and finished goods. We have determined that there is a convergence in EU countries in terms of maritime transportation network. This result shows that economic integration leads to improvements not only in the incomes of poorer countries but also in their transportation networks.

Keywords: Convergence, Lineer shipping, Unit root

Are Housing and Ship Demolition Markets Integrated? Evidence From Turkey

Kamil Özden EFES

pp. 94 - 100   |  DOI: 10.29329/actanatsci.2021.350.02


The purpose of this study is to investigate the impact of the demand for new houses to ship demolition prices in Turkey through new house sales statistics and Turkish ship demolition prices. In this direction, asymmetric causality test is used which allows to separate the shocks contained in the variables and to determine the causal relationships between these shocks. According to test results, causality relations are determined from positive shocks in house sales to positive shocks in demolition price and from negative shocks in house sales to negative shocks in demolition price. On the other hand, any significant causality from demolition prices to new house sales cannot be determined. This situation shows that changes in the new house sales are determinative for ship demolition prices in Turkey.

Keywords: Maritime economics, Demolition prices, Asymmetric causality test

Effects of Temperature and Nitrogen Concentration on Growth and Lipid Accumulation of the Green Algae Chlorella vulgaris for Biodiesel

Şafak Seyhaneyıldız Can, Edis Koru, Semra Cirik, Gamze Turan, Hatice Tekoğul & Tuğba Subakan

pp. 101 - 108   |  DOI: 10.29329/actanatsci.2021.350.03


This study investigated the effect of different temperatures and different nitrogen concentrations on the lipid content and biomass of Chlorella microalgae. In this study, algae were cultured in five media with different amounts NaNO_{3} as 3, 1.5, 0.80, 0.40 g/L, and three temperatures (10, 20, 30 °C). The results of the experiments showed that the optimal temperature and nitrogen concentration for the biomass increase in Chlorella vulgaris are 30°C and 3 g/L, respectively. It was observed that biomass decreased and lipid amount increased due to the decrease in nitrogen concentration. The high lipid amount of 20.80% dry weight (DW) was obtained from the algae produced at 30°C in the free-nitrate medium. The contribution of temperature change to lipid production was not as effective as nitrogen deficiency in the study. According to the fatty acid analysis results made by GC-FID, C. vulgaris seems suitable for biodiesel production because it contains medium-length (C16-C18) fatty acid chains.

Keywords: Chlorella vulgaris, Nitrogen starvation, Temperature, Lipids biodiesel

Effect of Homalothecium sericeum (Hedw.) Schimp. Extract on SOD1 Activity in Rat Tissues (Kidney, Adrenal Gland, Ovary)

Özlem Yayıntaş, Latife Ceyda İrkin & Şamil Öztürk

pp. 109 - 117   |  DOI: 10.29329/actanatsci.2021.350.04


Homalothecium sericeum (Hedw.) Schimp. is growing in habitats such as walls and roofs. It is supported by the studies that moss contains antioxidant, antimicrobial and antitumoral compounds. It was aimed to determine the immunoreactivity of Cu / Zn SOD enzyme in the kidney, adrenal gland, and ovarian tissues of rats due to the increase in the dose of moss extract. In this study, 1 mL of distilled water were given control groups (G1), 50 mg/kg (G2), 100 mg/kg (G3), 300 mg/kg (G4) and 500 mg/kg (G5) moss extract were administered by gavage for 30 days another groups. At the end of the experiment period, the tissues taken from the rats were subjected to routine histopathological procedures. Cu /Z n SOD primary antibody was applied using immunohistochemical staining methods to detect immunoreactivity. The study was terminated by using the Kruskal-Wallis test, which is one of the nonparametric tests. To determine the differences between the groups by evaluating the stained tissue samples with the image analysis system in the light microscope. A significant difference was found in the dose-related positivity of the kidney, ovarian and adrenal gland tissues of the groups given moss extract p. It has been determined that H. sericeum species increases Cu/Zn SOD enzyme activity in the kidney, adrenal gland and ovarian tissues, and its cytotoxic effects shows a dose-related increase in the histopathological table.

Keywords: Cu/Zn SOD (SOD1), Kidney, Adrenal gland, Ovary, Moss, Immunohistochemistry

Determination of Sexual Dimorphism in the Freshwater Blenny, Salaria fluviatilis (Asso, 1801), Distributed in Brackish Water Habitats

Sule Gurkan & Deniz Innal

pp. 118 - 123   |  DOI: 10.29329/actanatsci.2021.350.05


The present study aimed to determine the presence of the sexual dimorphism based on the morphometric measurements in a total of 60 samples (♀: 26; ♂: 14, immature; 20) which were obtained in April 2017 from the population of Salaria fluviatilis which shows distribution in the brackish waters in the Karpuzçay Creek (Antalya, Turkey). As a result of the morphometric analysis performed in both sexes of samples, it has been determined that there were differences between body parts in terms of total length (TL), dorsal fin length (DFL), snout length, and eye diameters in the head area. Accordingly, it has been observed that the lengths of allometric growing body parts of males were greater than that of females. The properties of sexual dimorphism in the body parts of freshwater blenny cause significant differences between sexes in brackish water forms. The differences in male individuals such as TL and long DFL are important criteria for the selection of large male individuals for sexual selection in mating. It was thought that the increase in snout length and eye diameter in the head region gives males some advantages in various areas such as feeding performance from the habitat, male selection of females in mating, and swimming performance.

Keywords: Blennid species, Salaria fluviatilis, Dimorphic structure, Morphometric features, Phenotypic response

Review Articles

A Mini-Review on Polycyclic Aromatic Hydrocarbons (PAHs) in Some Smoked Fish

Nuray Çiftçi & Deniz Ayas

pp. 124 - 129   |  DOI: 10.29329/actanatsci.2021.350.06


The effects of sources that cause pollution in the environment in organisms can occur in different ways. The participation of polycyclic aromatic hydrocarbons (PAHs), one of the pollutants caused by organic materials, into aquatic ecosystems by washing from the atmosphere and soil causes accumulation in aquatic ecosystems and is easily transported to the upper trophic zones through the food chain. Consumption of these products with high nutritional value poses a threat to human health. The processing of these products, which are widely consumed as fresh, with different processes is another way to remain under the influence of PAH. As it is known, PAHs are formed as a result of pyrolysis and prosynthesis of organic materials that are not sufficiently burned. In this sense, smoked products that are not produced under suitable conditions may carry a risk for the formation of PAH. In this study, the factors that cause PAH formation in smoked products and the appropriate processing processes developed to eliminate these factors were compiled.

Keywords: PAH, Smoked Fish, Formation, Toxicity, Prevention

Original Articles

ICCAT Inspections in Turkey and Turkey’s National Legislation Compliance With the ICCAT Recommendations

Raziye Tanrıverdi

pp. 130 - 140   |  DOI: 10.29329/actanatsci.2021.350.07


It was determined that bluefin tuna fishing within the scope of the International Commission for the Conservation of Atlantic Tunas (ICCAT) inspections was carried out in accordance with the 19-04 ICCAT Recommendation in Turkey. In the swordfish fishery, it was observed that the 16-05 ICCAT Recommendation was not completely compatible with Turkey’s national legislation. In the 16-05 ICCAT Recommendation; the fishing gear was determined as the longline in swordfish fishery, the length of the pelagic longlines and the number of hooks were limited, the minimum weight limit was set on swordfish, and the transshipment operations at sea of swordfish was prohibited in the fishing season. However, these legal regulations were not available in Turkey’s national legislation. The following issues could be evaluated as the reasons why these regulations were not included in Turkey’s national legislation; the majority of the fishing vessels engaged in swordfish fishery in the seas of Turkey are less than 12 meters in total length, the fishing vessels of 12 meters in length or more can only use the first fishing gear, the length of pelagic swordfish longlines and the number of hooks used in Turkey are far below the regulations set forth in 16-05 ICCAT Recommendation, the caught swordfish are landed as a whole, and the majority of swordfish fishery vessels stay for a day or 2-3 days for fishing at sea. The ICCAT inspections in the swordfish fishery were carried out according to the 16-05 ICCAT Recommendation in Turkey. The necessary information and incentives should be provided for the fishing vessels of less than 12 m in length, which had obtained swordfish fishery permits, to use fuel without special consumption tax, in order to monitor them electronically via Vessel Tracking Module. In order to control the quota in swordfish fishery, it should be obligatory to use a paper logbook for fishing vessels less than 12 meters in length. In addition, an application can also be made to install a Vessel Monitoring System on fishing vessels less than 12 m that will catch swordfish.

Keywords: Audit institutions, Electronic monitoring tools, Control, Inspection, Recommendation

Review Articles

A Review of Reported Bacterial Diseases and Antibiotic Use in Tilapia Culture in the Philippines

Albaris Tahiluddin & Ertuğrul Terzi

pp. 141 - 147   |  DOI: 10.29329/actanatsci.2021.350.08


Aquaculture has become important to meet the demand for animal food both in local and international markets due to the increasing world population. Tilapias are one of the significant cultured species worldwide, in which the Philippines is one of the leading tilapia-producing countries. Tilapias are the second most preferred fish in the Philippines, constituting about 12% of its total aquaculture production in 2018. Cultivation of tilapias is a practice nationwide, mostly performed in fish ponds and cages in various environments. Despite being an almost hardy fish, the investigation of tilapias for bacterial infections also allowed us to follow the changing bacterial world. In this study, we have reviewed articles that previously reported bacterial diseases and the use of antibiotics in tilapia culture in the Philippines. Streptococcosis, Motile Aeromonas Septicemia, and Pseudomonas infection caused by Streptococcus agalactiae and S. iniae, Aeromonas hydrophila, and Pseudomonas fluorescens and P. aeruginosa, respectively, were the identified fish diseases. Chloramphenicol, ampicillin, tetracycline, and erythromycin were among the most commonly used antibiotics in tilapia culture.

Keywords: Tilapia, Bacterial disease, Antibiotics, Philippines

Original Articles

The Effects of Mucilage Event on the Population of Critically Endangered Pinna nobilis (Linnaeus 1758) in Ocaklar Bay (Marmara Sea, Turkey)

Deniz Acarlı, Sefa Acarlı & Semih Kale

pp. 148 - 158   |  DOI: 10.29329/actanatsci.2021.350.09


This paper aimed to understand the potential effects of the mucilage event on the critically endangered Pinna nobilis in Ocaklar Bay located at the southern Marmara Sea. Underwater surveys were carried out in October 2020 and July 2021. The study area covers 500 m^{2} that was divided into 5 main zones having 100 m^{2} areas (10×10 m). Then, each main zone was separated into sub areas covering 25 m^{2} (5×5 m). The habitat structure, depth, and availability of the mucilage event were observed by SCUBA diving equipment in sub areas. During the underwater observations, the total number of dead and alive individuals was counted as 228 of which 130 individuals were alive and 98 were dead. The minimum and maximum population density (including both dead and alive individuals) of P. nobilis was found to be between 10 individuals per 100 m^{2} and 112 individuals per 100 m^{2} in the study area, respectively. The mortality rates were calculated as 35.96% and 16.12% for the years 2020 and 2021, respectively. This paper puts forward that the P. nobilis population could be resistant to extreme environmental stress and even juvenile individuals (smaller than 15 cm) were recruited in the study area during the mucilage event.

Keywords: Critically endangered species, Pinna nobilis, Mucilage, Mortality, Survival, Marmara Sea

Length-Weight Relationships of Four Symphodus Species (Perciformes: Labridae) off Gökçeada Island (Northern Aegean Sea, Turkey)

Özgür Cengiz

pp. 159 - 165   |  DOI: 10.29329/actanatsci.2021.350.10


The present work provides length-weight relationships (LWRs) of four Symphodus species off Gökçeada Island (Northern Aegean Sea, Turkey). The sampling was ensured between November 2013 and December 2014 from commercial fishmongers. This study presents the most recent and the broadest analysis of the LWRs for the following studied species: Symphodus ocellatus, Symphodus tinca, Symphodus mediterraneus, Symphodus rostratus. The b value varied between 2.81 and 3.37, whereas r^{2} aligned from 0.89 to 0.95.

Keywords: Length-weight relationships, Symphodus species, Gökçeada Island, Turkey

Effects of Annual Grass with the Mixtures of Legume on Agronomic Growth of Plants

Fırat Alatürk, Ahmet Gökkuş & Baboo Ali

pp. 166 - 176   |  DOI: 10.29329/actanatsci.2021.350.11


This study has been carried out in order to determine the variations in the vegetative characteristics of the mixtures of legume and cereal crops. Experiments were conducted according to the randomized complete block design using three replications of flowerpots. In the experiment; 1, 2 and 4 annual grass, Hungarian vetch and hairy vetch along with their double mixtures have been taken from per flowerpot. Effects of lean and mixed cultivation on plant characteristics (plant height, number of branches, total wet and dry weight and total root weight) and nutritional characteristics (NDF, ADF, ADL, crude protein, crude ash, digestibility of dry and organic matter, and total fiber) of crops were examined in this study. According to the results of our research work, as the number of plants per flowerpot increased the total wet and dry weight and root mass increased, too, in terms of plant characteristics particularly, in mixed sowing, the amount of upper soil surface and underground organic mass increased. Ratios of NDF, ADF and fiber in the mixture of cereals with legumes have decreased, while the digestibility of crude protein, crude ash, dry and organic matter has increased in case of nutritional characteristics. On the other hand, the ratios of NDF and ADF have increased, while there was a decrease in crude protein and crude ash ratios in the mixture of legumes with cereals. This indicates that annual grass along with hairy vetch and Hungarian vetch can be cultivated in winter both for obtaining higher grass production as well as to provide more organic matter to soil. It is concluded that the most suitable mixing ratios to be the two-fold and four-fold ratios of perennial grass along with the single ratio of vetches.

Keywords: Nutritional characteristics, Botanical characteristics, Crude protein, ADF, Cereal

Fish Consumption Preferences and Habits in Babaeski and Demirköy Districts of Kırklareli

Serkan Tozakçı & Musa Bulut

pp. 177 - 191   |  DOI: 10.29329/actanatsci.2021.350.12


Fish consumption is very important for a healthy and balanced diet. It is recommended to consume fish for the development of the brain and immune system from a young age. In order to avoid or overcome diseases such as heart, atherosclerosis and cholesterol in later ages, the importance of fish consumption should be increased. In this context, it is necessary to take measures to determine fish consumption habits and accordingly. For these reasons, this study was carried out to determine fish consumption and habits of people living in Demirköy and Babaeski districts of Kırklareli province. Within the scope of quantitative research origin, survey method was used. A questionnaire was used to determine fish consumption and habits as a data collection tool. After the applications with a total of 250 people, the data were analyzed with the SPSS 25 program. Analysis data were evaluated by tabulating frequency and percentage. In addition, the relationship between the monthly income of the participants from both districts and the frequency of fish consumed in a month was determined by chi-square analysis. It was determined that there were similarities in the fish preferences of the people participating in the study from Demirköy and Babaeski. In determining fish consumption preferences and habits, monthly income level, number of people in the family, hunting season, and freshness of the fish were also evaluated. It was concluded that the places to buy fish were different in both districts, and there was a relationship between monthly income and the amount of fish consumed in a month. It is thought that fish consumption can be increased with the opening of markets where people can buy fresh fish in all seasons, and the fish prices should be determined by associating them with monthly income.

Keywords: Fish consumption, Consumption habits, Kırklareli, Babaeski, Demirköy

Issue Information

In Memoriam: Prof. Dr. Yılmaz Emre (1957-2021)

Acta Natura et Scientia Editorial

pp. i - vi   |  DOI: 10.29329/actanatsci.2021.350.13


This volume is dedicated to our editorial board member and colleague Prof. Dr. Yılmaz EMRE who was devoted to aquaculture, fisheries, marine and freshwater biology, and microplastics.

In Antalya, Turkey, on August 22, at the age of 64, Prof. Dr. Yılmaz EMRE, a scientist at the Faculty of Science at Akdeniz University, Turkey, passed away due to the Covid-19 pandemic. The departure of our colleague, who was a member of the editorial board of our journal, represents a major loss for the Turkish scientific community.

Dr. Yılmaz EMRE was born on February 1, 1957, in Şanlıurfa, Turkey. He graduated from Selçuk University, Faculty of Science and Arts (Bachelor of Science Degree in Biology, 1982). He obtained a Master of Science degree in Medical Biology at Selçuk University, Department of Medical Biology (at the Faculty of Medicine), 1987, and earned a Philosophy of Doctorate degree in Biology at Bursa Uludağ University, Department of Biology, 1992. He became a full professor in 2016.

He worked as a biologist in the Bursa Fisheries Regional Directorate (Turkey) between 1982-1985, Bursa Provincial Directorate (Ministry of Agriculture and Rural Affairs, Turkey) between 1985-1989, Antalya Kepez Fisheries Production Directorate between 1989-2003. He also served as a founding director at the Mediterranean Fisheries Research, Production and Training Institute (Ministry of Agriculture and Forestry, Turkey) from 2005 to 2013. He worked as the Deputy General Manager of Fisheries and Aquaculture (Ministry of Agriculture and Forestry, Turkey) in 2016. He worked as the dean of the Faculty of Science at Akdeniz University between 2016-2017, and he worked as an academic at Akdeniz University from 2013 to 2021. He was the Turkey correspondent of the European Inland Fisheries Advisory Commission (EIFAC) (Food and Agriculture Organization (FAO) of the United Nations) for seven years.

His main areas of interest were aquaculture, fisheries, marine and freshwater biology. He has published more than 130 original scientific papers, studies and reports. He shared his knowledge and scientific experiences with young researchers throughout his life and trained many young researchers. Therefore, Dr. Yılmaz Emre’s passing created an unfillable void for his family, loved ones, and friends.

We would like to express the sadness of the loss of Dr. Yılmaz Emre, a great mentor and scientist. We hope that he enjoys a lovely and peaceful afterlife. Dr. Yılmaz Emre was also loved and will be respected by his worldwide academic family who will remain forever grateful.

Keywords: Obituary