TY - JOUR T1 - Optical characterization of chromophoric dissolved organic matter at eutrophic and oligotrophic parts of a semi-enclosed bay (İzmir, Aegean Sea) TT - Yarı-kapalı bir körfezin (İzmir, Ege Denizi) ötrofik ve oligotrofik kısımlarında kromoforik çözünmüş organik maddenin optik karakterizasyonu AU - Alyürük, Hakan AU - Kontaş, Aynur PY - 2021 DA - June DO - 10.12714/egejfas.38.2.09 JF - Ege Journal of Fisheries and Aquatic Sciences JO - EgeJFAS PB - Ege Üniversitesi WT - DergiPark SN - 2148-3140 SP - 199 EP - 210 VL - 38 IS - 2 LA - en AB - Optical characterization of chromophoric dissolved organic matter (CDOM) from İzmir Bay (Aegean Sea) waters was investigated. For sampling, surface and subsurface seawater from 7 stations were collected in summer 2015. Excitation-emission matrix (EEM) spectra of each sample were recorded on a fluorescence spectrophotometer. The results showed that dissolved organic carbon (DOC) concentrations and EEM peaks were increased from the outer bay to inner bay stations. EEM peaks indicated the presence of both humic-like and protein-like components which were higher at middle-inner bays than outer bay. Spearman’s rank correlation coefficients for EEM peak intensities and DOC concentrations were highly positive (p<0.05). HIX found between 0.73-3.51, whereas BIX ranged from 0.31 to 0.96 in the bay. Humification degree of CDOM in the middle-inner bays were higher compared to outer bay stations. High HIX values in the middle-inner bays could be linked to the presence of Melez stream (heavily polluted), other streams, rain run-offs and maritime activities at İzmir Bay. High BIX values in the middle-inner bays indicated presence of freshly produced DOM from bacterial origin. Optical characterization of CDOM could be used for tracing fluorescent DOM components and determining different DOM sources (autochthonous or allochthonous) in further studies. KW - chromophoric dissolved organic matter KW - dissolved organic carbon KW - fluorescence KW - seawater KW - İzmir Bay N2 - Bu çalışmada, İzmir Körfezi (Ege Denizi)’nden alınan deniz suyunda kromoforik çözünmüş organik madde (KÇOM)'nin optik karakterizasyonu araştırılmıştır. Deniz suyu örnekleri 7 istasyonda yüzey ve yüzey-altı derinliklerden 2015 yılı yaz mevsiminde toplanmıştır. Her bir örneğin uyarma-emisyon matris (UEM) spektrumu bir floresans spektrofotometresi aracılığıyla kaydedilmiştir. Sonuçlar, çözünmüş organik karbon (ÇOK) ve UEM pik şiddetlerinin dış körfezden iç körfeze doğru arttığını göstermiştir. UEM pikleri, hem hümik asit benzeri hem de protein benzeri organik madde bileşenlerinin orta-iç körfezlerde dış körfeze kıyasla daha yüksek olduğunu ortaya koymuştur. Spearman'ın sıralama korelasyonu testleri sonucunda UEM pik şiddetleri ve ÇOK konsantrasyonları arasında yüksek pozitif ilişki bulunduğu saptanmıştır (p<0.05). Körfez genelinde hümikleşme indeksi (HI) 0.73-3.51 aralığında, biyolojik indeks (BI) ise 0.31-0.96 aralığında değişim göstermiştir. KÇOM'a ait hümikleşme derecesi orta-iç körfezlerde dış körfeze kıyasla daha yüksek tespit edilmiştir. Orta-iç körfezlerde gözlenen yüksek HI değerlerinin yüksek kirlilik yükü taşıyan Melez çayının varlığı, iç körfeze ulaşan diğer yüzey sularının varlığı, yağmur ile denize sürüklenebilen karasal organik maddeler ve İzmir Körfezi'ndeki denizcilik aktiviteleri ile ilişkili olduğu düşünülmektedir. Orta-iç körfezlerde gözlenen yüksek BI değerleri ise özellikle bakteriyel kökenli ve yeni üretilmiş çözünmüş organik madde üretimi ile ilişkilendirilebilir. 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DOI:10.1016/S0045-6535(98)00166-0 UR - https://doi.org/10.12714/egejfas.38.2.09 L1 - https://dergipark.org.tr/tr/download/article-file/1212064 ER -