MARINE REPORTS (MAREP)

Exploring Doctor fish (Garra rufa, Heckel, 1846) breeding: A concise review

ihsan ÇELIK — 2023-12-05

Garra rufa

is a fish species belonging to the Cyprinidae family. Referred to as the "Doctor Fish" due to its utilization in the treatment of certain skin diseases, Garra rufa can easily thrive even in high-temperature thermal waters. When these fish come into contact with individuals entering thermal waters, they create a massaging effect through their mouth-touch actions on the human body. Consequently, these fish are widely used in the tourism sector, particularly in SPA centers. This method of use has spread to many regions worldwide. Each year, millions of Garra rufa are used in this manner. Therefore, active businesses globally require a substantial number of healthy fish annually. To meet the necessary demand, there is a need for Garra rufa aquaculture facilities. Except for a few small-scale entrepreneurs in Türkiye, there are no professionally managed Garra rufa aquaculture operations. To fill this gap in the field, supporting the cultivation of this species is vital. This article provides fundamental and general information about Garra rufa aquaculture. Sharing such information with the public is important in offering ideas to aspiring entrepreneurs interested in cultivating this species.

Effects of ammonia on different biological traits of the Orange Mud Crab (Scylla olivacea)

Shoaib MUHAMMAD — 2023-12-05

The orange mud crab (Scylla olivacea) is currently one of the most emerging crustacean species for coastal aquaculture, particularly in the Asian region. This species is sensitive to various aspects of water quality parameters. Ammonia is considered as one of the most common pollutants in crab farms that adversely affect overall production. Therefore, the present study observed the effects of different experimental doses of ammonia (0PPM, 5 PPM and 10 PPM) to investigate the effects on various aspects of cellular, physiological, biochemical and genetic alterations in the orange mud crab (Scylla olivacea). Significantly lower hemocyte counts were observed for the 5 PPM and 10 PPM ammonia treatments compared to the control group while no significant difference was detected between the two treatment groups. Ammonia treatments significantly altered expression pattern of the selected set of candidate genes. The α-amylase (growth gene) showed reduced expression (1.5–2 fold lower) in treatments while Toll like receptor (immune response gene) and Acetyl-CoA Carboxylase (metabolic gene) also showed significantly lower expression levels in treatment groups compared to the control. Significantly higher (P < 0.05) and constant rates of O₂ consumption in the control group throughout the experiment indicate that these crabs faced no stress and performed faster growth. Therefore, crabs in the control group (0 PPM) showed almost double growth (increase in body weight) compared to treatment groups (5 PPM and 10 PPM). Results indicate that different experimental doses of ammonia significantly altered the expression of candidate genes together with changes in physiological (O₂ consumption rates, growth), biochemical (total hemocyte counts, glucose and serotonin levels) and cellular (gill ultrastructure) parameters that adversely affected growth and mortality of crabs. Therefore, attempts are encouraged to maintain minimum or zero ammonia levels for sustainable mud crab farming across the coastal regions of Bangladesh.

Evaluation of the impact of different size and shape polyethylene microplastic in Nile tilapia (Oreochromis niloticus)

Ümit ACAR — 2023-12-05

Plastic waste that is discharged into the aquatic environment can eventually break down into different size particles known as microplastics (MP). MPs have become a significant concern due to their potential negative effects on fish species. In this study, the effects of sublethal concentrations of various size and shape polyethylene microplastics (PE-MPs) on Nile tilapia were investigated on numerous levels, including hematological and DNA damage in blood. For this purpose, the phsysiological effects of freshwater fish species Nile tilapia (Oreochromis niloticus) exposed to PE-MPs at control (0 mg/L), 5 mg/L, 10 mg/L, 25 mg/L and 50 mg/L for 14 days were investigated. In Nile tilapia PE-MPs exposure caused a significant decrease in hematological parameters. DNA damage in blood cells of fish exposed to PE-MPs was significantly higher than in the control group. Consequently, our findings show that PE-MPs affect many physiological parameters by causing oxidative stress-induced DNA damage in adult fish, and MPs should be considered a potent environmental pollutant when the rate in water is more than 10 mg/L for Nile tilapia.

Effect of fish size on nitrogen utilization in Japanese flounder, Paralichthys olivaceus (Temminck & Schlegel)

Orhan UYAN — 2023-12-05

Information on nitrogen utilization of varying size of Japanese flounder is essential in the formulation of cost-effective and low-pollutant diets. To do that, total ammonia nitrogen (TAN) excretion (mg-N/100 g fish) of different size of Japanese flounder (small size, S_S = 13.5 ± 0.40 g; medium size, S_M = 41.2 ± 1.15 g; large size, S_L = 119.0 ± 2.74 g) was monitored every 2 h following 24 h after feeding with the diets containing 40, 46, 52, 58 or 64% protein. Results indicated that the TAN excretion (mg-N/100 g fish/d) of SS and SM were significantly (P<0.05) higher than that of the SL in each dietary protein level. The only peak on post-prandial TAN excretion occurred 2 - 4 h after feeding in S_S and S_M. However, the fish of S_L tended to reach to the peak with slightly longer time than those of S_S and S_L. TAN excretion significantly (P<0.05) increased with increasing nitrogen (protein) intake in all fish size. At the same protein level, TAN excretion decreased with increasing fish size. No interactive effect between dietary protein level and fish size was observed on TAN excretion. The relationship between nitrogen intake and TAN excretion was identified by linear regression in each size, and intercepts of the equations represented the ration of ingested nitrogen diverted to ammonia. S_Lshowed more effective nitrogen utilization compared to S_S and S_M. The results indicated that nitrogen utilization of Japanese flounder was size-dependent. In conclusion, to optimize the protein level in diets for Japanese flounder, size dependent absolute dietary protein requirement must be established.

Examination of the structural chemistry of the otoliths of Red porgy, Pagrus pagrus by Raman analysis

Bayram KIZILKAYA — 2023-12-05

The present study focused the determine structural chemistry of the otoliths of red porgy, Pagrus pagrus, by using Raman analysis. The Raman analysis was conducted within the spectral scanning range of 3785-50 cm^-1. According to the Raman spectrum of otoliths, it becomes evident that there are two significant vibration bands that contribute to the otolith's main structure. The first is the intense vibration band at 1095 cm^-1, known as the symmetric (V1) band of the carbonate (-CO₃^-2) molecule. The second is the moderate in-plane bending band at 710 cm^-1, referred to as the in-plane (V4) band. These bands play a fundamental role in the structure of the otolith. Additionally, the Raman spectrum of the otolith reveals the presence of bands related to metal bonds forming with the carbonate (-CO₃^-2) molecule. These bands are observed at 155 and 210 cm^-1 and exhibit a moderate intensity. However, it is important to note that the specific cations or metal bonds involved cannot be determined solely from these bands. The Raman analysis of red porgy sagittal otolith composition and structure has provided valuable insights into the chemical composition and structure of these fish ear stones. The application of Raman spectroscopy to examine otoliths seems like a highly useful technique for understanding the composition and structure of these crystals. By utilizing Raman spectroscopy, researchers can gain valuable insights into the chemical composition and structures of otoliths in the inner ear. This examination allows for the determination of the minerals and elements contained within otoliths.

Surveying water quality parameters in shrimp ponds for best aquaculture practice in brackish waters of South Kalimantan, Indonesia

Deddy YANIHARTO — 2023-12-05

This study aims to survey the water quality and condition of brackish water ponds in Kotabaru Regency, South Kalimantan Province-Indonesia. The study was conducted in January 2019 initiated by the Representative Office of Bank Indonesia. The observed water quality parameters include physical (pH, temperature, oxygen etc.), chemical (nitrite, nitrate, ammonia, phosphate) and heavy metal contamination concentrations (Pb, Cd, Hg). Based on primary data from the survey results, supporting secondary data and observations of the characteristics of brackish water aquaculture ponds, it is necessary to apply good aquaculture practice methods through the application of Integrated Multi Trophic Aquaculture (IMTA) technology.

Analyzing meteorological data of Strait of Canakkale by using trend methods and evaluating their effects on ship traffic

Burhan TAŞLI — 2023-12-05

Strait of Canakkale is a waterway that opens to the Mediterranean for countries bordering the Black Sea and has no alternative. It proves this with the number of passes reaching up to 50,000 annually. Therefore, any negative changes that may occur in the Strait of Canakkale will cause serious damage not only to Türkiye but to many countries. One of the most parameters of navigation in maritime is meteorological conditions. If a place has a stable meteorological cycle, it brings predictable effects to its geography, and this has a positive impact on navigational safety. However, meteorological changes disrupt this order and cause a more transitional weather condition. The aim of this study was to evaluate data between 1995-2020 from 3 meteorological stations selected within the marine area of the Strait of Canakkale with trend analysis performed using Serial Correlation, Mann-Kendall test and Sen's trend slope methods for possible influences on maritime transportation. Trend analysis methods were used to predict the future situation according to datas. Before analyzing the trend methods, serial correlation was investigated to find out whether the data were serially dependent. Sen method and Mann-Kendall test were applied in this study. There was no significant trend in total precipitation amounts and average sea water temperatures. On the other hand, an increasing trend was observed in monthly average temperature values. It is estimated that it will cause navigational restrictions in the Strait of Canakkale as temperature increases will cause a decrease in water level, increased fog formation and an increase in wind strength.