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    A CASE STUDY: ECOLOGICAL QUALITY STATUS OF SUSURLUK RIVER BASIN (MARMARA SEA)
    (Parlar Scientific Publications (P S P), 2019) Albayrak, Serhat; Caglar, Senem; Mulayim, Aysegul; Kurt-Sahin, Guley; Balkis, Husamettin; Cinar, Nur Findik; Atabay, Hakan
    This study was carried out with the aim of determining the Ecological Quality Status (EQS) of coastal transitional waters of Susurluk River Basin (Marmara Sea). Macrozoobenthic invertebrate material was collected in May of 2013 from six stations in triplicate by means of a van Veen grab. Shannon-Weaver Diversity Index and associated Pielou's Evenness Index together with biotic indices AMBI and BENTIX were calculated. Some ecological variables (Secchi disc depth, temperature, salinity, dissolved oxygen, pH, total phosphorus, total nitrogen, silica, Chlorophyll-a) of the sea water and total organic carbon of the sediment were also measured. Ecological Quality Status at each station was assessed by considering individual dominancy of sensitive and tolerant species, results from univariate/biotic indexes and some ecological parameters. When EQS of the basin is evaluated as a whole, it was seen that there was not any station in Good or High EQS at the study area, stations were in Poor or Bad EQS at the stations where the River meets the sea, while the stations off the River mouth were in Moderate EQS. Both species pattern of macrozoobenthic invertebrate communities and ecological parameters determined in the basin such as TOC and nutrients present the negative impacts of the River over the basin and indicate the necessity of efficient precautions to be taken.
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    Assessment of the Spatial and Temporal Variation of Mesozooplankton in the Southern Black Sea, Türkiye
    (Sinop University, 2024) Üstün, Funda; Bat, Levent; Bayram Partal, Fatma; Atabay, Hakan; Mutlu, Sabri; Tolun, Leyla; Uygun, Orçin
    This study investigated the taxonomic composition, abundance, and biomass values of mesozooplankton in the marine area in front of two important rivers (Sakarya River and Yesilirmak River) and the largest port located on the Black Sea coast in Türkiye (Samsun Port) in July 2019 and January 2020. The average mesozooplankton abundance and biomass were 4187.3 ind. m-3 and 89.7 mg m-3 in Sakarya River, 3638.5 ind. m-3 and 78.2 mg m-3 in Samsun Port, and 3327.6 ind.m-3 and 77.6 mg m-3 in Yesilirmak River, respectively. In July 2019, the highest abundance value of mesozooplankton (8581 ind. m-3) was recorded at SAK08 station off Sakarya River due to the copepod $Acartia$ $clausi$ (3279 ind. m-3). In July 2019, the highest biomass value of mesozooplankton (209.34 mg m-3) was found at YSL07 station off Yesilirmak River with the contribution of the copepod $Centropages$ $ponticus$ (77.90 mg m-3). In January 2020, the highest abundance and biomass values of mesozooplankton (4035 ind. m-3 and 66.45 mg m-3) were detected at SLI05 station off Samsun Port due to copepod $Acartia$ $clausi$. A difference in mesozooplankton species composition between the two sampling periods was identified. While Cladocera species and copepod $Acartia$ $tonsa$ were exclusive at the sampling stations in July 2019, copepod $Calanus$ $euxinus$, $Pseudocalanus$ $elongatus$ and $Oithona$ $similis$ were observed at the sampling stations in January 2020. Also, in January 2020, the presence of freshwater Cladocera species was detected off Sakarya River. The changes in biodiversity were determined to depend on temperature changes and riverine input.
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    Integrated assessment of eutrophication in the southern Black Sea waters, using the Nested Environmental Status Assessment Tool
    (Pergamon-Elsevier Science Ltd, 2023) Tan, Ibrahim; Atabay, Hakan; Evcen, Alper; Kurt, Guley; Taskin, Ergun; Beken, Colpan Polat
    This research deals with the land-based pressures on the southern Black Sea coast (Turkey), with the objective of assessing their eutrophication impacts. In this context, reference values of some of the eutrophication indicators were calculated, and eutrophication assessment was carried out for this area using the holistic approach NEAT (Nested Environmental Status Assessment Tool). In addition, correlations between NEAT results of coastal regions and pressure-impact analysis methods were investigated. In the determined Spatial Assessment Unit (SAU) areas, 9 indicators were evaluated according to the SAU surface, both with and without weighting by their size the overall assessment of the Turkish Black Sea coast is good (0.70) and moderate (0.57) environmental status, for non-weighting and weighting by SAUs, respectively, with a high confidence level. With this study, we concluded that the sensitivity of the assessment tool needs to be increased. Despite these results, an appropriate number of indicators to represent the water column should be added. It is important to include the phytoplankton variable in the evaluation in future studies. In addition, this study, which uses NEAT allows identifying problematic environmental areas that require attention and action from managers and policymakers.
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    Marine litter occurrence in the river-influenced Black Sea coast
    (Turkish Marine Research Foundation-Tudav, 2020) Stoica, Elena; Atabay, Hakan; Bat, Levent; Ciuca, Andreea; Creanga, Silvia; Marin, Dragos; Oztekin, Aysah
    Composition and abundance of anthropogenic litter were investigated on adjacent coastal beaches of three rivers flowing into the North-Western and Southern Black Sea. A single sampling survey was conducted during the period August - September 2019 within 4 sectors of sandy beaches with different level of urbanization situated at the Romanian and Turkish littoral of the Black Sea. The results of study evinced total of 3916 items with the maximum litter accumulations found on the Turkish coast. The most-represented items of anthropogenic litter in the evaluated samples were plastics, paper/cardboard, wood and glass/ceramic. Plastics made up the main share of litter on Black Sea coastal beaches near the river mouths (65-95%). The types of plastic items ranged from 15 to 54 among the sites, of which cigarette butts, plastic pieces (2.5 cm > < 50 cm), polystyrene and plastic caps/lids drinks constituted the highest number of artificial polymeric material. The characteristic of plastic litter composition of each selected Black Sea beach is attributable to river and human influences. Fragments and small plastic items were predominant for most of the beaches, including wild beaches and those that had lower levels of urbanization, confirming that riverine outflows have an important impact on plastic litter pollution on Black Sea coastal beaches.