Satellite-Based Analysis of Night-Time Radiance Dynamics in Near-Shore and Offshore Aquaculture Systems in Çandarlı Bay (Northern Aegean Sea, Türkiye)

Year 2026, Volume: 9 Issue: 2, 734 - 741, 15.03.2026

Deniz Devrim Tosun

https://doi.org/10.34248/bsengineering.1862201

https://izlik.org/JA66YB67XA

Abstract

Artificial Light at Night (ALAN) has emerged as a growing environmental concern in coastal regions, where marine aquaculture operations coexist with expanding urbanization and tourism infrastructure. This study presents a decadal satellite-based assessment of night-time radiance dynamics associated with marine aquaculture systems in Çandarlı Bay, a semi-enclosed coastal environment in the Northern Aegean Sea, Türkiye. Monthly composites from the Visible Infrared Imaging Radiometer Suite Day/Night Band (VIIRS DNB) were analyzed for the period 2014–2024 to examine long-term trends in relative radiance at offshore and near-shore aquaculture sites, alongside marine and terrestrial control zones. Aquaculture installations were classified into two spatial typologies: a near-shore island-associated cluster and an offshore solitary system. To evaluate aquaculture-related radiance independently from broader coastal illumination, an Aquaculture Light Index (ALI) was developed to quantify radiance contrast relative to a dark-water marine reference. Temporal trends were assessed using STL decomposition, the Mann–Kendall trend test, and Theil–Sen slope estimation. The offshore aquaculture system exhibited no significant long-term trend in relative radiance, indicating a stable nocturnal light signature over the study period. In contrast, near-shore aquaculture sites showed a statistically significant decline in relative radiance contrast, coinciding with increasing night-time brightness in the adjacent terrestrial control area. These findings indicate that observed changes in aquaculture-related radiance are primarily associated with intensifying coastal background illumination rather than progressive increases in farm-level lighting. The study demonstrates the importance of spatial context and background radiance when interpreting satellite-derived ALAN signals in coastal aquaculture environments.

Keywords

Artificial Light at Night (ALAN) , Marine aquaculture , Night-time radiance , Satellite-based analysis , Coastal urbanization

Ethical Statement

Ethics committee approval was not required for this study because there was no study on animals or humans.

Supporting Institution

This research did not receive any funding.

Project Number

-

Thanks

-

References

• Almeida, J., Costa, C., & Da Silva, F. N. (2017). A framework for conflict analysis in spatial planning for tourism. Tourism Management Perspectives, 24, 94–106. https://doi.org/10.1016/j.tmp.2017.07.021
• Aydın, İ., Öztürk, R. Ç., Eroldoğan, O. T., Arslan, M., Terzi, Y., Yılmaz, S., Diken, G., Yıldırım, Ö., Bodur, T., Gültepe, N., Erdem, Ö. A., Evliyaoğlu, E., Dürrani, Ö., Gülen, S., Batır, E., Altınok, İ., & Sevgili, H. (2025). An in‐depth analysis of the finfish aquaculture in Türkiye: Current status, challenges, and future prospects. Reviews in Aquaculture, 17(2), Article e70010. https://doi.org/10.1111/raq.70010
• Elvidge, C. D., Baugh, K., Zhizhin, M., Hsu, F. C., & Ghosh, T. (2021). VIIRS night-time lights. In Remote sensing of night-time light (pp. 6–25). Routledge.
• Elvidge, C. D., Zhizhin, M., Baugh, K., & Hsu, F. C. (2015). Automatic boat identification system for VIIRS low light imaging data. Remote Sensing, 7(3), 3020–3036. https://doi.org/10.3390/rs70303020
• FAO. (2024). The state of world fisheries and aquaculture 2024: Blue transformation in action. Food and Agriculture Organization of the United Nations. https://www.fao.org/documents/card/en/c/cc0461en
• Gumus, V., Avsaroglu, Y., & Simsek, O. (2022). Streamflow trends in the Tigris river basin using Mann−Kendall and innovative trend analysis methods. Journal of Earth System Science, 131, Article 34. https://doi.org/10.1007/s12040-021-01770-4
• Hall, C. M. (2021). Tourism and fishing. Scandinavian Journal of Hospitality and Tourism, 21(3), 241–248. https://doi.org/10.1080/15022250.2021.1955739
• Halpern, B. S., & Selkoe, K. A. (2024). Reaping the synergies between ocean aquaculture and fisheries. One Earth, 7(10), 1670–1673. https://doi.org/10.1016/j.oneear.2024.09.007
• Le Gouvello, R., Hochart, L. E., Laffoley, D., Simard, F., Andrade, C., Angel, D., & Marino, G. (2017). Aquaculture and marine protected areas: Potential opportunities and synergies. Aquatic Conservation: Marine and Freshwater Ecosystems, 27, 138–150. https://doi.org/10.1002/aqc.2821
• Li, J., Lu, L., & Li, X. (2025). Estimating city emission function with VIIRS/DNB data and vegetation phenology. IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing, 24331–24341. https://doi.org/10.1109/JSTARS.2025.3610127
• Liu, S., So, C. W., & Pun, C. S. J. (2021, July). Analyzing long-term artificial light at night using VIIRS monthly product with land use data: Preliminary result of Hong Kong. 2021 IEEE International Geoscience and Remote Sensing Symposium IGARSS (pp. 6821–6824). IEEE. https://doi.org/10.1109/IGARSS47720.2021.9553915
• Liu, S., So, C. W., & Pun, C. S. J. (2025). Analyzing the sources and variations of nighttime lights in Hong Kong from VIIRS monthly data. Remote Sensing, 17(8), Article 1447. https://doi.org/10.3390/rs17081447
• Maccarrone, V., & Quinci, E. M. (2024). Assessment of artificial light at night across geographical features in the Sicilian coastal zone. Land, 13(12), Article 2219. https://doi.org/10.3390/land13122219
• Markus, T. (2024). Finding the right spot: Laws governing the siting of aquaculture activities. Frontiers in Aquaculture, 3, Article 1428497. https://doi.org/10.3389/faquc.2024.1428497
• Sarıkaya Levent, Y., Şahin, E., & Levent, T. (2024). The role of tourism planning in land-use/land-cover changes in the Kızkalesi tourism destination. Land, 13(2), Article 151. https://doi.org/10.3390/land13020151
• Schultz, K. M., Scyphers, S. B., Hughes, A. R., Kimbro, D. L., Kirk, S., & Grabowski, J. H. (2026). Coastal resident's perceptions and attitudes of the visual impacts of oyster aquaculture cultivation methods along the Atlantic coast of the US. Ocean & Coastal Management, 271, Article 107951. https://doi.org/10.1016/j.ocecoaman.2025.107951
• Shi, K., Huang, C., Yu, B., Yin, B., Huang, Y., & Wu, J. (2014). Evaluation of NPP-VIIRS night-time light composite data for extracting built-up urban areas. Remote Sensing Letters, 5(4), 358–366. https://doi.org/10.1080/2150704X.2014.905728
• Sumaila, U. R., & Villasante, S. (2025). Surging blue economy, increasing conflict risks and mitigation strategies. Frontiers in Marine Science, 12, Article 1499386. https://doi.org/10.3389/fmars.2025.1499386
• Trull, O., García-Díaz, J. C., & Peiró-Signes, A. (2022). Multiple seasonal STL decomposition with discrete-interval moving seasonalities. Applied Mathematics and Computation, 433, Article 127398. https://doi.org/10.1016/j.amc.2022.127398
• Wood, S. E., & Filgueira, R. (2022). Drivers of social acceptability for bivalve aquaculture in Atlantic Canadian communities. Ecology and Society, 27(3), Article 34. https://doi.org/10.5751/ES-13358-270309
• Xiao, Q., Zhou, M., Lyu, Y., Lu, J., Zhang, K., Figueiro, M., & Bauer, C. (2023). County-level artificial light at night (ALAN) in the contiguous US (2012–2019): Spatial variations, temporal trends, and environmental justice analyses. Environmental Science and Pollution Research, 30(54), 115870–115881. https://doi.org/10.1007/s11356-023-30572-y