Türk Boğazlar Sistemi’nde Mesozooplankton Biyokütlesinin İlkbahar ve Sonbahar Mevsimlerindeki Alansal ve Vertikal Dağılımı

Zooplanktonik organizmalar pelajik besin ağının şekillenmesinde ve biyokimyasal döngülerin gerçekleşmesinde anahtar rol oynamaktadır. Zooplankton biyokütlesi ve dağılımı hakkında bilgi sahibi olmak, bu canlıların ekosistemdeki organik madde ve enerji akışına katkılarını tahmin etmek için önem arzetmektedir. 2008 yılının Nisan ve Ekim aylarında Türk Boğazlar Sistemi (TBS)’nde tek hat boyunca belirlenen istasyonlardan WP-2 plankton kepçesi (ağ göz açıklığı 200μm) ile zooplankton örnekleri toplanmıştır. Bu örneklerden ölçülen biyokütle değerlerinin epipelajik bölgedeki alansal ve dikey dağılımı belirlenerek bölgedeki bu konuyla ilgili bilgi eksikliği giderilmeye çalışılmıştır.TBS’de ortalama mesozooplankton mevcut stoğu alansal ve dikey olarak farklılık göstermiştir. Mesozooplankton biyokütlesi genel itibariyle ilkbaharda yüzey karışım tabakasında yoğunlaşmış, derinlik ile birlikte azalmıştır. Sonbahar periyodunda ise geçiş tabakası ortalama mesozooplankton biyokütle değerleri bakımından daha yüksek bulunmuştur. Genel olarak, boğazlarda yüksek olan bu değerler, Marmara Denizi’nin iç bölgelerinde özellikle kuzey batısında oldukça düşmüştür. Bölgedeki biyokütle dağılımında istasyon derinliği, derinlik tabakaları ve oksijen miktarı etkili olmakla birlikte, örnekleme periyodu boyunca gerçekleştiği bildirilen musilaj olayının sıcaklık ve tuzluluk gibi çevresel parametrelerin etkisini büyük ölçüde maskelediği düşünülmektedir

Experiment design and bacterial abundance control extracellular H2O2 concentrations during four series of mesocosm experiments

The extracellular concentration of H2O2 in surface aquatic environments is controlled by a balance between photochemical production and the microbial synthesis of catalase and peroxidase enzymes to remove H2O2 from solution. In any kind of incubation experiment, the formation rates and equilibrium concentrations of reactive oxygen species (ROSs) such as H2O2 may be sensitive to both the experiment design, particularly to the regulation of incident light, and the abundance of different microbial groups, as both cellular H2O2 production and catalase–peroxidase enzyme production rates differ between species. Whilst there are extensive measurements of photochemical H2O2 formation rates and the distribution of H2O2 in the marine environment, it is poorly constrained how different microbial groups affect extracellular H2O2 concentrations, how comparable extracellular H2O2 concentrations within large-scale incubation experiments are to those observed in the surface-mixed layer, and to what extent a mismatch with environmentally relevant concentrations of ROS in incubations could influence biological processes differently to what would be observed in nature. Here we show that both experiment design and bacterial abundance consistently exert control on extracellular H2O2 concentrations across a range of incubation experiments in diverse marine environments. During four large-scale (>1000 L) mesocosm experiments (in Gran Canaria, the Mediterranean, Patagonia and Svalbard) most experimental factors appeared to exert only minor, or no, direct effect on H2O2 concentrations. For example, in three of four experiments where pH was manipulated to 0.4–0.5 below ambient pH, no significant change was evident in extracellular H2O2 concentrations relative to controls. An influence was sometimes inferred from zooplankton density, but not consistently between different incubation experiments, and no change in H2O2 was evident in controlled experiments using different densities of the copepod Calanus finmarchicus grazing on the diatom Skeletonema costatum (<1 % change in [H2O2] comparing copepod densities from 1 to 10 L−1). Instead, the changes in H2O2 concentration contrasting high- and low-zooplankton incubations appeared to arise from the resulting changes in bacterial activity. The correlation between bacterial abundance and extracellular H2O2 was stronger in some incubations than others (R2 range 0.09 to 0.55), yet high bacterial densities were consistently associated with low H2O2. Nonetheless, the main control on H2O2 concentrations during incubation experiments relative to those in ambient, unenclosed waters was the regulation of incident light. In an open (lidless) mesocosm experiment in Gran Canaria, H2O2 was persistently elevated (2–6-fold) above ambient concentrations; whereas using closed high-density polyethylene mesocosms in Crete, Svalbard and Patagonia H2O2 within incubations was always reduced (median 10 %–90 %) relative to ambient waters

The distribution of copepod functional groups in İskenderun Bay (northeastern Mediterranean Sea)

Iskenderun Bay is one of the most important area in the Levantine Sea due to having wide continental shelf resulting in higher primary production in contrast to ultraoligotrophic trophic structure of Levantine Basin. In the present study, we aimed to characterize the distribution of copepod functional groups in İskenderun Bay. Monthly samplings were realized using a WP-2 net (200μm) at inshore and offshore stations during March 2010- February 2011. In the study area, copepods dominated the mesozooplankton population during the most of year. A total of 92 copepod species were observed, however their composition varied seasonally. Adult copepod species were separated into six functional groups according to Benedetti et al. (2016). The copepod community was dominated by filter feeders (including herbivores) with peak abundance in the late spring and contribution of this group was higher in coastal area. Large cruise feeders were rarely observed at coastal station and proportion of this group in offshore was very low. Small active ambus feeders were higher during early spring in coastal station and during whole spring in offshore station. Small mixed feeders had comparatively higher ratio at coastal station and dominated by the coastal copepod community in some periods (%85 on April-10 and %60 on July-10). Contribution of this group to copepod community was very low in offshore region. Small active ambush feeder’s populations were higher in late autumn in both coastal and offshore regions. Small cruise feeders (including herbivores and detritivores) were common in the copepod community and its proportion was higher in offshore region. In conclusion, clear temporal variations in terms of copepod functional groups were observed in both coastal and offshore stations. Trophic elements (pico-, phyto- and protozoplankton) and environmental variables (temperature and salinity) were the main factors affecting the distribution of copepod functional groups

İskenderun Körfezi (Kuzeydoğu Akdeniz) Kıyısal Sularında Flaccisagitta enflata (Grassi, 1881)’nın Beslenmesi ve Bağırsak İçeriği Üzerine İlk Gözlemler

In this study, it was aimed to characterize the feeding and diet composition of the most common pelagic chaetognath Flaccisagitta enflata . Zooplankton samples were collected using a WP-2 zooplankton net (200 ?m) at three stations in the İskenderun Bay in October 2016, December 2016 and March 2017. F. enflata was the most abundant chaetognath in all samples and its proportion varied from 42 to 94%. Younger stages (I and II) dominated the population of F. enflata. In total, 1663 specimens were examined, but only 185 contained prey in their guts. The total food-containing ratio and the number of prey items for this chaetognath species were 11% and 0.1, respectively. These values varied for different maturity stages. Most food items were unidentified due to digestion. Copepods were the main food resource (36.8%) for the species. Cannibalism was also observed. This study is the first to describe F. enflata feeding behaviour in the coastal area of İskenderun Bay. The preliminary results show that the feeding ratios were within the ranges reported for other regions in the eastern Mediterranean Sea.Mevcut çalışmada, en yaygın pelajik ketognat olan Flaccisagitta enflata ’nın beslenmesi ve besin kompozisyonu karakterize edilmeye çalışılmıştır. Zooplankton örnekleri, İskenderun Körfezi’nde Ekim ve Aralık 2016, Mart, 2017 periyotlarında 3 istasyonda WP-2 zooplankton kepçesi (200 ?m) ile toplanmıştır. Ketognatlar içinde, F. enflata, tüm periyotlarda baskın tür olarak gözlenmiş olup, oranı %42–94 arasında değişim göstermiştir. Erken olgunluk aşamaları (I ve II) F. enflata populasyonunda baskın olarak gözlenmiştir. Toplam 1663 birey incelenmiş olup, bunlardan sadece 185 bireyin bağırsağında besine rastlanmıştır. Bu tür için toplam besin içerme oranı (FCR) ve ketognat başına düşen besin miktarı (NPC) sırasıyla %11 ve 0.1 olarak bulunmuştur. Bu değerler olgunluk aşamalarına göre farklılık göstermiştir. Çoğu besin sindirilmiş olduğundan dolayı tanımlanamamıştır. Tanımlanan besin canlılar arasında kopepodlar ana besin kaynağını oluşturmuştur (%36.8). Bununla birlikte kannibalizm’de gözlenmiştir. Bu çalışmada ilk kez İskenderun Körfezi’nin kıyısal alanında F. enflata ’nın beslenmesi ile ilgili bilgiler elde edilmiş ve ilk gözlemler beslenme oranlarının Doğu Akdeniz’in diğer alanlarından elde edilen sonuçlar ile benzer olduğunu göstermiştir

Türkiye'nin Güney Karadeniz'inde Oithona davisae Ferrari F.D.&Orsi, 1984 (Copepoda: Oithonidae) Bulunuşunun İlk Kaydı

Mevcut çalışmada, Oithona davisae Ferrari F.D.&Orsi, 1984 türünün Sinop, Türkiye kıyısındaki ilk bulunurluğu kaydedilmiştir. Türün bolluk ve biyokütle verisi ve toplam kopepod içerisindeki ergin birey ve kopepodit evrelerinin oranı incelenmiştir. Zooplankton örnekleri Ocak-Aralık 2009'da vertikal çekim yöntemiyle aylık olarak 112 ?m ağ göz açıklığındaki plankton kepçesi ile toplanmıştır. Bu tür örnekleme periyodu boyunca ilk kez Eylül ayında belirlenmiş ve takip eden diğer aylarda da varlığı tespit edilmiştir. En yüksek bolluk ve biyokütle değeri Kasım 2009'da (1485,35 birey.m-3, 2,9 mg.m-3) kaydedilmiştir. Kasım ayında toplam kopepod bolluğuna katkısı %39,89 ve biyokütleye katkısı ise %14,35 idi. Sonuç olarak, elde edilen veriler yerli olmayan kopepod O. davisae Sinop kıyısının ekolojik koşullarına adapte olduğunu göstermektedir.We report the first occurrence of Oithona davisae Ferrari F.D.&amp;Orsi, 1984 in the Sinop coast, Turkey. Data on the abundance and biomass of this species, and the proportion of adult and copepodite stages in the total copepods were investigated. The zooplankton samples were collected monthly by vertical hauls with plankton net of 112 ?m mesh size from January to December 2009. However, O. davisae was observed for the first time in September, and continued to be observed for the remainder of the sampling period. The highest abundance and biomass of this species were recorded in November 2009 (1485.35 ind.m-3 and 2.9 mg.m-3, respectively), which was 39.89% in the abundance and 14.35% of the biomass of the total copepods in November. In conclusion, the non-indigenous copepod species, O. davisae, has adapted to the ecological conditions of the Sinop coast

First distribution record of the invasive copepod Oithona davisae Ferrari and Orsi, 1984, in the coastal waters of the Aegean Sea

The occurrence of the invasive nonindigenous copepod Oithona davisae Ferrari and Orsi, 1984, is reported for the first time in the Aegean Sea. The data we collected in August 2017 from 14 stations along the Turkish coast of the Aegean Sea reveal the spatial distribution of O. davisae between the openning of the Dardanelles Strait in the north and the Izmir Bay in the south. The O. davisae individuals, in seven meso‐ zooplankton samples collected from a single station, were consistently found in the inner part of the Izmir Bay from April 2015‐October 2016. The abundance of female O. davisae ranged from 4 ind./m3 in April 2015 to 31,524 ind./m3 in July 2016 and contributed to the total oithonid female population by 10.8% in April 2015 and 92.8% in September 2016. Our results show that this species is well established in the inner part of Izmir Bay and that it has become a permanent component of the copepod community in the area

NTIOXIDANT SUBSTANCES, PIGMENTS AND PROXIMATE COMPOSITION OF SOME SEAWEEDS FROM THE NORTHEASTERN MEDITERRANEAN COAST OF TURKEY

Objective: Seaweeds are examined in three groups as red, green and brown algae according to their color. They are distributed until the depth where sunlight can reach in the marine environments. They contain many nutritional substances and they are used as food and dietary supplements. The aim of this study is to determine the antioxidant substances, pigments and proximate composition of two seaweed species (C. corniculata, S. acinarum). Methods: Seaweeds were collected from the northeastern Mediterranean coast of Turkey in spring and summer. Epiphytes and other substances were removed and the samples were successively washed with sea water and distilled water. The seaweed samples were analyzed for proximate composition; lipid content by the Bligh and Dyer method, total crude protein by the Kjeldahl method. The phenolic content of seaweeds was determined by Folin-Ciocalteu method. Total chlorophyll a and carotenoid content of seaweed species were analyzed spectrophotometrically. Result and Discussion: Seaweeds are commonly used as important part of the diet of coastal communities. In this study, nutritional substances, antioxidant and pigment contents were investigated in two seaweed species (C. corniculata, S. acinarum). Lipid (1.32% wet wt.) and protein (8.23% wet wt.) content of S. acinarum was found to be high compared to those of C.corniculata. In addition, phenolic matter (64.33±3.86 mg/g dry wt.), flavonoids (7.86±0.47 mg/g dry wt), chlorophyll a (0.90 mg/g) and carotenoids (0.57 mg/g) levels of S. acinarum were higher than that of C. corniculata. In both species, lipid levels were higher in summer while protein levels were higher in summer only in C. corniculata. Phenolic contents were higher in summer in two species. On the other hand, chlorophyll a and carotenoid content of two species were found higher in spring. The results indicate that seaweeds contain valuable materials for human nutrition and many industrial purposes. There is a significant potential for algal products industry and it is very likely that this sector will expand in the future

Zooplankton Community Structure at the İskenderun Bay (Northeastern Mediterranean Sea) in 2016

Introduction: Inshore areas are very sensitive systems in which hydrographical values change rapidly. These sharp changes are reflected in zooplankton communities. In this respect, the status of zooplankton populations at the west inshore area of İskenderun Bay in 2016 was investigated in the present study. Material and Methods: The present study was conducted seasonally at five stations between April and December in 2016. Zooplankton samples were collected using with WP-2 net (200μm messh size). Zooplankton abundance was determined as individual per -3 -3 m and zooplankton biomass was measured as dry weight per m . Temperature and salinity were measured using YSI 650 CTD probe at the surface and depths of 5m., 10 m. and 15 m. Chlorophyll-a and phytoplankton abundance were obtained from water samples taken simultaneously at the same depths using a Niskin water sampler. The spearman rank correlation was applied to estimate relationship between environmental factors. Results and Discussion: The annual mean abundance and biomass of the zooplankton -3 -3 were 2723±1505 ind. m and 9.02±4.73 mg m , respectively. These values changed -3 -3 seasonally and the lowest values were seen in winter (523 ind. m , 2.3 mg m ), and the -3 -3 highest values were observed in the spring (6210 ind. m , 18.1 mg m ). Two major peaks in zooplankton abundance were observed in the spring and summer. The first zooplankton biomass peak occurred in spring, similar to the abundance peak, however, the second peak was observed in autumn instead of in summer. Fourteen meroplankton and 13 holoplankton groups were identified in the study area. Cladocera was the dominant group in summer, whereas Copepoda had the highest abundance during the other seasons. Other common zooplankton groups were Appendicularia, Bivalvia Cirripedia Echinodermata, Doliolida, Chaetognatha, Hydrozoa, Doliolida, Appendicularia, and Polychaeta. The contribution of these groups varied seasonally. The proportion of meroplanktonic groups was higher in the spring and summer. Zooplankton abundance was significantly correlated with temperature, salinity, and trophic elements (diatom and dinoflagellate abundance)

Denizel Kladoserlerin Yumurtalık Koyu’ndaki (Iskenderun Körfezi) Dağılımı

Araştırma, 25 Kasım 2005 – 24 Ağustos 2006 tarihleri arasında Yumurtalık (Adana) Koyu’nda yıl içerinde 4 kez örnekleme yapılarak gerçekleştirilmiştir. Örnekler kıyıdan açığa doğru belirlenen 4 istasyondan horizontal olarak 200 µm göz açıklığına sahip WP2 tip standart zooplankton kepçesi kullanılarak alınmıştır. Çalışmada Penilia avirostris, Evadne spinifera, Pseudoevadne tergestina, Evadne nordmanni, Pleopis polyphamoides türleri ve Podon sp. bulunmuştur. En yüksek bolluk değeri (123,95 n/m3) Mayıs ayındaki örneklemelerde en düşük ise kasım ayındakilerde bulunmuştur

Acclimatization succession of new non-indigenous cyclopoid copepod Oithona davisae in the southern coast of Turkey: Hamsilos Bay

Hamsilos Bay is one of the most important regions on the Black Sea Coast of Turkey. This region is within a natural protected area in the first and second degree, and there are no settlement areas around it. Moreover, many fish species choose this area for breeding and rearing activities. In this respect, characterizing the abundance distribution of non-indigenous copepod Oithona davisae in relation to environmental variables, such as natural site and the effect of the other copepod species in the community, were the aims of the present study. Zooplankton samplings were collected monthly from seven stations in July 2015 – June 2016 by using a plankton net with a 112-μm mesh size and 50-cm diameter. O. davisae was observed during the whole sampling period and a dominant species in the July-December period. The highest abundance of this species was recorded in October 2015 (2127.98±371.29 ind/m 3 ), which was 58.8% of the abundance of the total copepods; however, the lowest was observed in the winter and spring period. Copepodit 3-2-1 and adult specimens of O. davisae were very abundant in the autumn season. Copepodit 5-4 was mostly observed in the winter and spring seasons. The abundance of this species was well correlated with trophic elements and physiochemical variables (temperature, salinity, DO, total nitrogen, organic matter and chlorophyll-a). In conclusion, the acclimatization of this species in the Hamsilos Bay has been very successful. It was observed that the temporal range of this species, which is known to be distributed only in autumn in close areas, was extended and especially prevailed in the Copepod communities during warm periods