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    Acoustic effects of underwater drilling and piling noise on growth and physiological response of Nile tilapia (Oreochromis niloticus)
    (Wiley, 2020) Kusku, Halit; Yigit, Umut; Yılmaz, Sevdan; Yigit, Murat; Ergün, Sebahattin
    Human-generated noises are considered as underwater sound pollution with potential short- or long-term impacts on behavioural responses and physiological reaction of aquatic living organisms. Few investigations are available so far on long-term influences of impulsive and continuous sound sources on physiological response of fish. In the present study, opercula beat rates and pectoral wing rates were monitored as a physiological stress response of ventilation in Nile tilapia (Oreochromis niloticus) exposed to long-term repeated and continued sounds generated from underwater construction work. Fish responded to underwater sound treatment with significantly increased opercula beat-and pectoral wing movements. Maximum ventilation rate was observed as a startle response of fish at initial exposure to underwater sound. The ventilation rates remained at high levels over the first 4 weeks and showed a declining trend thereafter. Fish growth was almost stable for the first 4 weeks, but shifted forward from day 45 onwards. We found strong evidence that fish could attune to repeated playbacks of underwater noise exposures since we found higher specific growth rates for the sound exposed fish from day 45 onwards until day 120, a so-called 'catch-up growth endeavour'.
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    Öğe
    Acoustic sound-induced stress response of Nile tilapia (Oreochromis niloticus) to long-term underwater sound transmissions of urban and shipping noises
    (Springer Heidelberg, 2020) Kusku, Halit
    Human-made impacts on the acoustic environment from marine industries is becoming a more significant issue with increasing public concern of environmental consequences. Even though there are several reports with scientific evidences on harmful influences of anthropogenic underwater sounds on the aquatic ecosystem, most of the studies so far dealt with trigger effects of short term noise impacts on aquatic animals. In the present study, however, long-term experimentation was conducted with Nile tilapia (Oreochromis niloticus) in order to figure out how fish may respond to long-term exposure of underwater sounds and if the level of response may change (increase or decline) over time. A startle reflex as a sign of stress was seen immediately at the start of the playbacks of ship noise or urban sounds in this study. Peaks of elevated respiratory movements of ventilation (opercula beats and pectoral wing rates) retained high over the following 30 days of sound initiation and underwent a declining trend over the following 90 days of exposure. At the end of the 120-day study period, the lowered response of fish after long-term sound exposure is likely due to the increased tolerance of fish to human-generated underwater sounds of urban and shipping noises. Different than short-term noise impacts, information on long-term exposure of anthropogenic underwater sounds is important for environmental management and setting new regulations for the sustainable use of water resources in the world.
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    Biofouling Control of Invasive Zebra Mussel (Dreissena polymorpha) Using Acoustic Energy
    (Hard, 2022) Kusku, Halit; Yigit, Murat; Yılmaz, Sevdan; Yigit, Umut; Ergün, Sebahattin
    Effects of increasing levels of audible sound energy (500, 1000, 5000 Hz frequency) on attachment strength and mortality rates of zebra mussels were investigated in a long-term study for the control and deterrence of zebra mussel infestation. All groups exposed to sound treatments presented weight loss by 1.09, 1.44 and 2.07% in the 500 Hz, 1.000 Hz, and 5.000 Hz frequency groups, respectively, while mussels receiving no sound showed an increasing trend in weight gain by 1.37%. The mortality rate increased with both increasing levels of sound frequency, and the time-length of exposure duration within the same frequency level. Attachment strength declined with induced mortality of zebra mussel after 20 days of sound exposure, and nearly 50% of zebra mussels died by sound treatment of 5000 Hz frequency after 100-days of exposure. The findings in this study demonstrate that sound energy is a potential tool and a practical option for preventive management and control of zebra mussel biofouling in freshwater ecosystems.
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    Color intensity and growth performance of common clownfish (Amphiprion ocellaris) enhanced by dietary Spirulina (Arthrospira platensis)
    (Springer, 2022) Guroy, Derya; Karadal, Onur; Mantoglu, Serhan; Kusku, Halit; Guroy, Betul
    In this study, the effect of dietary Spirulina (Arthrospira platensis) on color intensity, growth performance, total ammonia-nitrogen excretion (TAN), and profitability of common clownfish (Amphiprion ocellaris) was investigated. Three isoproteic (46%) and isolipidic (13%) diets were formulated as one control (C) and two different levels (15 and 30%) of Spirulina (SP15 and SP30) substituted for fish meal and cornmeal. Ten clownfish (initial body weight of 0.55 +/- 0.04 g) per aquarium were distributed to nine glass aquariums (60 L) with three replicates. Fish were hand-fed a day to the satiation thrice. Clownfish were weighed in bulk, and the photographs were taken biweekly during the 12-week experiment. The determined regions of the images were standardized with a raster graphics editor and recorded the color parameters by considering both CMYK (cyan magenta yellow key) and RGB (red green blue) models. After the feeding trial, fish were starved for 3 days, and the total ammonia-nitrogen (TAN) was analyzed with the ammonia salicylate method on the next day for 12 h. At the end of the trial, the final mean weights (FMW) and specific growth rates (SGR) of SP15 (FMW: 1.95 +/- 0.18 g, SGR: 1.75 +/- 0.04%/day) and SP30 (FMW: 2.05 +/- 0.14 g, SGR: 1.81 +/- 0.05%/day) were significantly higher than the C (FMW: 1.68 +/- 0.12 g, SGR: 1.58 +/- 0.06%/day) group (P < 0.05). Both color models have proved the enhancement of the skin coloration (significant improvements were recorded in the colors, including red, green, magenta, and key, P < 0.05). Also, it was determined that the TAN was decreased with the increase of the Spirulina level (29.8, 22.9, and 17.6 mg-N/100 g fish/12 h for C, SP15, and SP30, respectively) in the diet (P < 0.05). However, a high level of Spirulina in the diet negatively affected profitability. Consequently, common clownfish's growth, color, and TAN improved with the dietary Spirulina. Considering that Spirulina is an expensive raw material, adding it into the diet at medium levels (15%) is recommended.
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    Impacts of Urban Noise and Musical Stimuli on Growth Performance and Feed Utilization of Koi fish (Cyprinus carpio) in Recirculating Water Conditions
    (Central Fisheries Research Inst, 2019) Kusku, Halit; Ergün, Sebahattin; Yılmaz, Sevdan; Guroy, Betul; Yigit, Murat
    In the present study, effects of underwater sound transmission on growth, feed utilization and behavior of Koi fish (Cyprinus carpio, initial weight 3.67 +/- 0.18 g) was investigated via exposure to Urban Noise, Silk Road, Sufi Ney, and a Quran performance. Underwater sound transmissions were performed daily with playbacks between 08:00-08.30, 12:30-13:00, and 17:00-17:30 hours, throughout the feeding trial for a period of 90 days in a recirculating aquaculture system. An experimental group without any sound served as control. Results showed that musical stimuli tested in this study positively influenced fish growth and feed efficiency. Experimental fish presented slow growth performance during the first period however the disturbed swimming behavior of fish scattering in the tanks changed to a more regular swimming and improved growth thereafter, an indication of lower stress condition or acclimatization of fish to sounds. As a result, fish growths and feed efficiencies were influenced by musical stimuli with remarkably higher rates in the Quran performance and instrumental Sufi Ney treatments, compared to the Silk Road or the control group. Urban noise presented adverse effect on fish growth and feed efficiency. Hence, musical stimuli could be considered as a growth promoting factor ensuring fish welfare in intensive aquaculture facilities.