Oceanologia No. 60 (2) / 18

Contents

Letter to Editor


Original research article

Corrigendum

Original research article


Total benthic oxygen uptake in two Arctic fjords (Spitsbergen) with different hydrological regimes
Oceanologia 2018, 60(2), 107-113
https://doi.org/10.1016/j.oceano.2017.11.005

Lech Kotwicki1,*, Katarzyna Grzelak1,2, Krzysztof Opaliński3, Jan Marcin Węsławski1
1Institute of Oceanology Polish Academy of Sciences, Sopot, Poland;
e-mail: lechk@iopan.gda.pl,
*corresponding author
2Laboratory of Polar Biology and Oceanobiology, Faculty of Biology and Environmental Protection, University of Łódź, Łódź, Poland
3Cardinal Wyszyński University, Warsaw, Poland

keywords: Sediment oxygen uptake, Respiration partitioning, Carbon demand, Svalbard fjord Arctic

Received 8 July 2016, Accepted 27 November 2017, Available online 6 December 2017.

Abstract

Benthic total oxygen uptake (TOU) was measured in two Arctic fjords (NW Spitsbergen shelf) with different hydrological regimes: Hornsund with “cold” coastal Arctic waters and Kongsfjorden with “warm” Atlantic shelf waters. TOU rates in Kongsfjorden were more than 50% higher than in Hornsund. This is presumably related to the relatively higher biomass of bacterial and faunal (meiobenthos and macrofauna) communities in Kongsfjorden as compared to Hornsund caused by the source of organic matter: Kongsfjorden is dominated by marine, Hornsund by terrigenous organic matter. We conclude that the quality of organic matter supplied to marine sediments influences the biomass of benthic organisms and the rate of oxygen consumption. Therefore the Kongsfjorden sea bed has much higher oxygen uptake and hence a greater carbon demand than Hornsund.
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Seasonal influence of physico-chemical parameters on phytoplankton diversity, community structure and abundance at Parangipettai coastal waters, Bay of Bengal, South East Coast of India
Oceanologia 2018, 60(2), 114-127
https://doi.org/10.1016/j.oceano.2017.08.003

Manigandan Vajravelu1, Yosuva Martin1, Saravanakumar Ayyappan2,*, Machendiranathan Mayakrishnan1
1Centre of Advanced Study in Marine Biology, Annamalai University, Parangipettai, India
2Faculty of Marine Science, Centre of Advanced Study in Marine Biology, Annamalai University, Parangipettai, India;
e-mail: asarvaan@gmail.com
*corresponding author

keywords: Phytoplankton, Nutrient, CCA analysis, Diversity, Richness, Productivity

Received 3 May 2017, Accepted 25 August 2017, Available online 19 September 2017.

Abstract

The present investigation studied the seasonal variation between physico-chemical parameters and phytoplankton diversity, community structure and abundance; quantitative samples were collected on a monthly basis from April 2015 to March 2016 at Parangipettai coast, the Bay of Bengal (BOB). Statistical analyses were performed on physico-chemical parameters such as salinity, dissolved oxygen (DO), pH, temperature, nitrate, nitrite, silicate, and inorganic phosphate (IP). The significant (P < 0.0005) variation among seasons as well as a high influence of these parameters was observed on phytoplankton productivity. Totally, 117 species were identified, belonging to five different classes, Coscinodiscophyceae (62%), Bacillariophyceae (17%), Fragilariophyceae (8%), Dinophyceae (8%) and Cyanophyceae (5%). Throughout the study period, the occurrence of most dominant species was observed from class Coscinodiscophyceae and Bacillariophyceae. The phytoplankton species also showed significant changes according to seasonal variations as well as the nutrient availability. Phytoplankton attained their maximum population density during premonsoon; whereas minimum population was observed during monsoon. The performed statistical analysis on phytoplankton species, the Shannon & Wiener diversity index was found to be higher during postmonsoon and lower during monsoon season. The Canonical Correspondence Analysis (CCA) was used, to find out the seasonal relationship between phytoplankton and physicochemical parameters. Hence, the executed CCA results revealed that temperature, salinity, silicate, DO and IP have a higher influence on phytoplankton abundance.
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Composition and diel vertical distribution of euphausiid larvae (calyptopis stage) in the deep southern Adriatic
Oceanologia 2018, 60(2), 128-138
https://doi.org/10.1016/j.oceano.2017.09.001

Barbara Gangai Zovko1,*, Davor Lučić1, Marijana Hure1, Ivona Onofri1, Branka Pestorić2
1University of Dubrovnik, Institute for Marine and Coastal Research, Dubrovnik, Croatia
e-mail: barbara.gangai@unidu.hr
*corresponding author
2Institute of Marine Biology in Kotor, Kotor, Montenegro;

keywords: Euphausiid larvae, Mediterranean Sea, Secondary production, Vertical distribution, Weighted mean depth

Received 20 February 2017, Accepted 14 September 2017, Available online 6 October 2017.

Abstract

Diel changes in the vertical distribution and abundance of calyptopes were studied in the deepest area of the southern Adriatic over four seasons (July 2003, February 2004, October 2004, April 2009). Temperature variations were limited to the upper 100 m and salinity variations were small. Of previously known adult euphausiid species – 12 for the Adriatic (Gangai et al., 2012) and 13 for the Mediterranean (Mavidis et al., 2005) – calyptopes of 11 species of euphausiids were recorded. Abundance of calyptopes of all species was the highest in spring. Species were characterized according to their mean depth: surface (0–50 m), sub-surface (50–200 m), mesopelagic (200–800 m), or bathypelagic (800–1200 m) and vertical dispersion (scattered or non-scattered). Four diel patterns emerged: (i) nocturnal ascent to upper layers (Euphausia brevis, E. hemigibba, E. krohnii, Nematoscelis megalops, N. couchii), (ii) migration to upper layers at middle of the day and at night, and descent during the morning and evening (Stylocheiron maximum – only winter), (iii) weakly-migrating or non-migrating (S. longicorne), (iv) irregular migration independent of the day/night cycle (S. abbreviatum, S. maximum – during spring, summer and autumn, T. aequalis).
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Microbial plankton communities in the coastal southeastern Black Sea: biomass, composition and trophic interactions
Oceanologia 2018, 60(2), 139-152
https://doi.org/10.1016/j.oceano.2017.09.002

Ulgen Aytan1,*, Ali Muzaffer Feyzioglu2, Andre Valente3, Ertugrul Agirbas1, Elaine S. Fileman4
1Faculty of Fisheries, Recep Tayyip Erdogan University, Rize, Turkey;
e-mail: ulgen.kopuz@erdogan.edu.tr
*corresponding author
2Faculty of Marine Sciences, Karadeniz Technical University, Trabzon, Turkey
3Marine and Environmental Sciences Centre, Faculty of Sciences, University of Lisbon, Lisbon, Portugal
4Plymouth Marine Laboratory, Plymouth, United Kingdom

keywords: Phytoplankton, Microzooplankton, Carbon biomass, Microbial food web, Grazing, Black Sea

Received 13 February 2017, Accepted 28 September 2017, Available online 24 October 2017.

Abstract

We investigated biomass and composition of the pico-, nano- and microplankton communities in a coastal station of the southeastern Black Sea during 2011. We also examined trophic interactions within these communities from size-fractionated dilution experiments in February, June and December. Autotrophic and heterotrophic biomasses showed similar seasonal trends, with a peak in June, but heterotrophs dominated throughout the year. Autotrophic biomass was mainly comprised by nanoflagellates and diatoms in the first half of the year, and by dinoflagellates and Synechococcus spp. in the second half. Heterotrophic biomass was mostly dominated by heterotrophic bacteria, followed by nanoflagellates and microzooplankton. Dilution experiments suggest that nano- and microzooplankton were significant consumers of autotrophs and heterotrophic bacteria. More than 100% of bacterial production was consumed by grazers in all experiments, while 46%, 21% and 30% of daily primary production were consumed in February, June and December, respectively. In February, autotrophs were the main carbon source, but in December, it was heterotrophic bacteria. An intermediate situation was observed in June, with similar carbon flows from autotrophs and heterotrophic bacteria. Size-fraction dilution experiments suggested that heterotrophic nanoflagellates are an important link between the high heterotrophic bacterial biomass and microzooplankton. In summary, these results indicate that nano- and microzooplankton were responsible for comprising a significant fraction of total microbial plankton biomass, standing stocks, growth and grazing processes. This suggests that in 2011, the microbial food web was an important compartment of the planktonic food web in the coastal southeastern Black Sea.
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A fuzzy KNN-based model for significant wave height prediction in large lakes
Oceanologia 2018, 60(2), 153-168
https://doi.org/10.1016/j.oceano.2017.09.003

Mohammad Reza Nikoo1,*, Reza Kerachian2, Mohammad Reza Alizadeha1
1Department of Civil and Environmental Engineering, School of Engineering, Shiraz University, Shiraz, Iran;
e-mail: nikoo@shirazu.ac.ir
*corresponding author
2School of Civil Engineering and Center of Excellence for Engineering and Management of Civil Infrastructures, College of Engineering, University of Tehran, Tehran, Iran

keywords: Significant wave height prediction, Fuzzy K-nearest neighbor, Bayesian networks, Support vector regression, Regression tree induction

Received 20 May 2017, Accepted 28 September 2017, Available online 1 November 2017.

Abstract

Some algorithms based on fuzzy set theory (FST) such as fuzzy inference system (FIS) and adaptive-network-based fuzzy inference system (ANFIS) have been successfully applied to significant wave height (SWH) prediction. In this paper, perhaps for the first time, the fuzzy K-nearest neighbor (FKNN) algorithm is utilized to develop a fuzzy wave height prediction model for large lakes, where the fetch length depends on the wind direction. As fetch length (or wind direction) can affect the wave height in lakes, this variable is also considered as one of the inputs of the prediction model.
The results of the FKNN model are compared with those of some soft computing techniques such as Bayesian networks (BNs), regression tree induction (named M5P), and support vector regression (SVR). The developed FKNN model is used for SWH prediction in the western part of Lake Superior in North America. The results show that the FKNN and M5P model can outperform the other soft computing techniques.
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Investigating the role of air-sea forcing on the variability of hydrography, circulation, and mixed layer depth in the Arabian Sea and Bay of Bengal
Oceanologia 2018, 60(2), 169-186
https://doi.org/10.1016/j.oceano.2017.10.001

Atul Srivastava, Suneet Dwivedi*, Alok Kumar Mishra
K Banerjee Centre of Atmospheric and Ocean Studies and M N Saha Centre of Space Studies, University of Allahabad, Allahabad, UP 211002, India;
e-mail: suneetdwivedi@gmail.com
*corresponding author

keywords: Arabian Sea and Bay of Bengal, Air-sea forcing, Ocean general circulation model, Hydrography and circulation, Vertical stability

Received 11 April 2017, Accepted 2 October 2017, Available online 21 October 2017.

Abstract

An effort is made to understand and quantify the influence of near surface zonal and meridional winds, incoming shortwave radiation, and freshwater flux air-sea forcings on the seasonal variability of the hydrography, circulation, and mixed layer depth of the Arabian Sea (AS) and Bay of Bengal (BoB). Sensitivity experiments using an ocean general circulation model are carried out for this purpose in the Indian ocean around 65°–95°E, 5°–22°N during 1998–2014 (17 years). In the absence of near surface wind forcing, the sea surface temperature of the region greatly increases in all the seasons, whereas, in the absence of incoming shortwave radiation forcing, exactly opposite is the case. The sea surface salinity of the AS and BoB decreases in the absence of wind and shortwave radiation forcings, whereas, in the northern BoB it increases in the absence of freshwater flux forcing. The sub-surface changes in the stratification of temperature and salinity are also investigated. The influence of the air-sea forcings on the mixed layer depth of the region is found to be highly seasonally dependent. The effect of air-sea forcings on the seasonal variability of the upper ocean vertical stability is studied using the vertical shear of the horizontal velocity, buoyancy frequency, and energy required for mixing as quantifiers. The near surface wind forcing has highest contribution in changing the surface circulation of the region.
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Some probabilistic properties of deep water wave steepness
Oceanologia 2018, 60(2), 187-192
https://doi.org/10.1016/j.oceano.2017.10.003

Dag Myrhaug*
Norwegian University of Science and Technology (NTNU), Trondheim, Norway;
e-mail: dag.myrhaug@ntnu.no
*corresponding author

keywords: Wave steepness, Spectral steepness parameter, Phillips spectrum, JONSWAP spectrum, Joint frequency tables, Wave statistics

Received 2 June 2017, Accepted 12 October 2017, Available online 2 November 2017.

Abstract

This paper provides some probabilistic properties of the deep water wave steepness and the spectral wave steepness by using distributions based on data from the Norwegian continental shelf. Here the average statistical properties represented by the mean value and the standard deviation of the two steepness parameters are considered. Examples of results for the wave steepness are given for a Phillips spectrum and a family of JONSWAP spectra for wind sea, and for sea states described by a joint frequency table of significant wave height and mean zero-crossing wave period for combined wind sea and swell. The results for the spectral wave steepness are obtained by using a joint distribution of significant wave height and spectral wave steepness, and the average statistical features are given for joint frequency tables of significant wave height and mean zero-crossing wave period from three locations on the Norwegian continental shelf.
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Distribution of metals and extent of contamination in sediments from the south-eastern Baltic Sea (Lithuanian zone)
Oceanologia 2018, 60(2), 193-206
https://doi.org/10.1016/j.oceano.2017.11.001

Nijolė Remeikaitė-Nikienė1,2,*, Galina Garnaga-Budrė1,4, Galina Lujanienė2, Kęstutis Jokšas3,5, Algirdas Stankevičius1,4, Vitalijus Malejevas1,2, Rūta Barisevičiūtė2

1Environmental Protection Agency, Department of Marine Research, Klaipėda, Lithuania;
e-mail: n.remeikaite@gmail.com, n.remeikaite@aaa.am.lt
*corresponding author
2State Research Institute Center for Physical Sciences and Technology, Vilnius, Lithuania
3Nature Research Center, Institute of Geology and Geography, Vilnius, Lithuania
4Klaipėda University, Klaipėda, Lithuania
5Vilnius University, Vilnius, Lithuania

keywords: Metals, Enrichment factor, Geoaccumulation index, Contamination factor, The Baltic Sea, The Curonian Lagoon

Received 24 December 2016, Accepted 15 November 2017, Available online 2 December 2017.

Abstract

The distribution of metals (Pb, Cu, Cd, Ni, Cr, Zn) in surface sediments and the potential pollution sources in the south-eastern part (SE) of the Baltic Sea (Lithuanian zone) were investigated in relation to the environmental characteristics (amount of fine-grained particles, TOC content in sediments, origin of sedimentary organic matter, salinity, water depth) in 2011–2014. The higher metal concentrations were measured in sediments of the Curonian Lagoon and in the open waters. An approach using various environmental indices (enrichment factor EF, geoaccumulation index Igeo and contamination factor CF) was used to quantitatively assess a contamination degree. The principal component analysis (PCA) was applied in order to further scrutinize pollution from metal sources. The values of the contamination indices showed no/very low sediment contamination with Ni and Cr, minor–moderate contamination with Cu, Zn and Pb and moderate–considerable pollution with Cd. The strong relationships among metals suggested their similar distribution pattern and a combination of natural and anthropogenic sources. The higher metal concentrations coincided with an increasing amount of fine-grained fraction and organic carbon. In the territorial waters, the distribution of elements was related to the water depth. In addition, the binding of metals with insoluble iron sulphides might explain their high concentrations at the most remote and deepest stations.
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Assessment of wave climate and energy resources in the Baltic Sea nearshore (Lithuanian territorial water)
Oceanologia 2018, 60(2), 207-218
https://doi.org/10.1016/j.oceano.2017.10.004

Darius Jakimavičius*, Jūratė Kriaučiūnienė, Diana Šarauskienė
Lithuanian Energy Institute, Kaunas, Lithuania;
e-mail: darius.jakimavicius@lei.lt
*corresponding author

keywords: Wave climate, Wave modelling, Wave power, Baltic Sea, MIKE 21 NSW

Received 14 February 2017, Accepted 11 October 2017, Available online 3 November 2017.

Abstract

The main task of the present research was to analyse wave climate and evaluate energy resources in the Lithuanian territorial waters of the Baltic Sea. Wave and wind parameters were analysed according to long-term measurement site data. Distribution of wave parameters in the Baltic Sea Lithuanian nearshore was evaluated according to wave modelling results. Wave energy resources were estimated for three design years (high, median and low wave intensity). The results indicated that in the coastal area of Lithuania, waves approaching from western directions prevail with mean wave height of 0.9 m. These waves are the highest and have the greatest energy potential. The strongest winds and the highest waves are characteristic for the winter and autumn seasons. In the Baltic Sea Lithuanian nearshore, the mean wave height ranges from 0.68 to 0.98 m, while the estimated mean energy flux reaches from 0.69 to 1.90 kW m−1 during a year of different wave intensity. Distribution of energy fluxes was analysed at different isobaths in the nearshore. Moving away from the coast, both wave height and wave power flux increases significantly when water depth increases from 5 to 20 m. Values of the mentioned parameters tend to change only slightly when the sea is deeper than 20 m. In a year of median wave intensity, the mean wave energy flux changes from 1.10 kW m−1 at 10 m isobaths to 1.38 kW m−1 at 30 m isobaths. The identified differences of wave height and energy along the selected isobaths are insignificant.
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Microfouling development on artificial substrates deployed in the central Red Sea
Oceanologia 2018, 60(2), 219-231
https://doi.org/10.1016/j.oceano.2017.10.006

Ahmed A. Balqadi, Adnan J. Salama, Sathianeson Satheesh*
King Abdulaziz University, Jeddah, Saudi Arabia;
e-mail: ssathianeson@kau.edu.sa, satheesh_s2005@yahoo.co.in
*corresponding author

keywords: Biofilm, Biofouling, Nutrient cycling, Diatom, Larval settlement, Red Sea

Received 24 April 2017, Accepted 27 October 2017, Available online 15 November 2017.

Abstract

Microfouling is the initial step in the growth of biofouling on hard substrata submerged in marine waters. In this study, microfouling development on nylon nets submerged in the central Red Sea coast of Saudi Arabia was analyzed during the winter and summer seasons for a period of 5 days each. The results showed a well-established biofilm community on nylon nets submerged for 24 h, with bacteria and diatoms being the primary colonizers. Protein was the major organic component of the biofilm that developed on the nylon nets during the winter and summer seasons. Navicula spp., Nitzschia spp., Cylindrotheca spp., and Pluerosigma spp. were the dominant diatom species settled on the nylon nets. Pseudoalteromonas shioyasakiensis, Planomicrobium sp., Vibrio harveyi and Pseudoalteromonas rubra were the dominant bacteria isolated from the nylon nets. While the abundance of bacteria showed a positive correlation with the nutrient concentration of the biofilm during both winter and summer seasons, diatom density exhibited a significant positive relationship with the biofilm nutrients during the winter season only. The results also revealed significant seasonal variations in the abundance of microfouling organisms and accumulation of nutrients on nylon nets.
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Galveston Bay dynamics under different wind conditions
Oceanologia 2018, 60(2), 232-243
https://doi.org/10.1016/j.oceano.2017.10.005

David Salas-Monreal1,*, Ayal Anis2, David Alberto Salas-de-Leon3
1Universidad Veracruzana, Boca del Rio, Mexico;
e-mail: davsalas@uv.mx
*corresponding author
2Texas A&M University, Galveston, USA
3National Autonomous University of Mexico (UNAM), Ciudad Universitaria, Mexico City, Mexico

keywords: Suspended particle dispersion, Shallow estuarine dynamics, Galveston Bay dynamics, Ocean shallow water gyres

Received 25 May 2017, Accepted 17 October 2017, Available online 6 November 2017.

Abstract

The Regional Ocean Model System (ROMS) was used to simulate flow and hydrographic (temperature, salinity) patterns in a shallow, relatively flat-bottomed estuary with two subestuaries, one with an elongated shape and the other with a roughly circular shape. Simulations were used to elucidate the wind stress effect on a tidally formed cyclonic gyre in Galveston Bay, Texas (USA). The form factor suggests that Galveston Bay is a mixed, mainly diurnal system with tides that propagate out of phase by less than 1 h from side to side of the estuary. Temperature and salinity patterns suggest that the influence of the estuary extends oceanward, up to a distance commensurate with the 14 m depth isobath (∼10 km offshore), during a diurnal tidal cycle. A tidally generated cyclonic gyre was observed to form in the circular subestuary, suggesting that this region may be more productive than others. This tidally formed gyre appeared to weaken and even disappear under certain wind stress conditions. Simulations suggest that the entire bay was able to flush only under northeasterly wind conditions, while for all other wind directions (northwesterly, southeasterly and southwesterly), the water appeared to pile up in the circular subestuary. Furthermore, most of the ocean-bay exchange was found to occur through the north entrance to the bay where the effects of the gyre were observed. Thus, it is expected that much of the exchange of water-borne substances, pollutants and plankton between the bay and the ocean occurs through this entrance.
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Corrigendum


Corrigendum to “Aerosol physical properties in Spitsbergen's fjords: Hornsund and Kongsfjorden during AREX campaigns in 2014 and 2015” [Oceanologia 59 (2017) 460–472]
Oceanologia 2018, 60(2), I-II
https://doi.org/10.1016/j.oceano.2017.11.004

Piotr Markuszewski1,2,*, Anna Rozwadowska1, Małgorzata Cisek1, Przemysław Makuch1, Tomasz Petelski1
1Institute of Oceanology, Polish Academy of Sciences, Sopot, Poland;
e-mail: pmarkusz@iopan.da.plv
*corresponding author
2Centre for Polar Studies National Leading Research Centre, Sosnowiec, Poland

Available online 6 December 2017.

Refers to
Piotr Markuszewski, Anna Rozwadowska, Małgorzata Cisek, Przemysław Makuch, Tomasz Petelski
Aerosol physical properties in Spitsbergen's fjords: Hornsund and Kongsfjorden during AREX campaigns in 2014 and 2015
Oceanologia, Volume 59, Issue 4, October–December 2017, Pages 460-472
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