Oceanologia No. 60 (3) / 18
Original research article
Bioactive metabolites produced by Spirulina subsalsa from the Baltic Sea: Karolina Szubert, Magda Wiglusz, Hanna Mazur-Marzec
Budget of 90Sr in the Gulf of Gdańsk (southern Baltic Sea): Michał Saniewski, Tamara Zalewska
Coastal hydrodynamics beyond the surf zone of the south Baltic Sea: Rafał Ostrowski, Magdalena Stella, Piotr Szmytkiewicz, Jarosław Kapiński, Tomasz Marcinkowski
Parameters of wind seas and swell in the Black Sea based on numerical modeling: Boris Divinsky, Ruben Kosyan
Spatio-temporal variability of the size-fractionated primary production and chlorophyll in the Levantine Basin (northeastern Mediterranean): Nebil Yucel
Stokes transport in layers in the water column based on long-term wind statistics: Dag Myrhaug, Hong Wang, Lars Erik Holmedal
Microbial enzymatic activity and its relation to organic matter abundance on sheltered and exposed beaches on the Polish coast: Aleksander M. Astel, Katarzyna Bigus, Marcin Stec
Wind wave climate of west Spitsbergen: seasonal variability and extreme events: Kacper Wojtysiak, Agnieszka Herman, Mateusz Moskalik
Climate-related trends and meteorological conditions in the Porsanger fjord, Norway: Agata Cieszyńska, Małgorzata Stramska
The effects of cyanobacterial blooms on MODIS-L2 data products in the southern Caspian Sea: Karim Naghdi, Masoud Moradi, Keivan Kabiri, Majid Rahimzadegan
Impact of climate change on the Curonian Lagoon water balance components, salinity and water temperature in the 21st century: Darius Jakimavičius, Jūratė Kriaučiūnienė, Diana Šarauskienė
Ecosystem of the Polish part of the Vistula Lagoon from the perspective of alternative stable states concept, with implications for management issues: Ryszard Kornijów
Comparison of the burial rate estimation methods of organic and inorganic carbon and quantification of carbon burial in two high Arctic fjords: Katarzyna Koziorowska, Karol Kuliński, Janusz Pempkowiak
Original research article
Bioactive metabolites produced by Spirulina subsalsa from the Baltic Sea
Oceanologia 2018, 60(3), 245-255
Karolina Szubert*,1, Magda Wiglusz*,1, Hanna Mazur-Marzec*,1,2
1Institute of Oceanography, University of Gdańsk, Gdynia, Poland;
e-mail: firstname.lastname@example.org, email@example.com
2Institute of Oceanology Polish Academy of Sciences, Sopot, Poland;
Spirulina subsalsa, Cyanometabolites, Cytotoxicity, Proteases inhibitors, Mass spectrometry
Received 2 September 2017, Accepted 17 November 2017, Available online 6 December 2017.
Cyanobacteria are known producers of compounds with possible medical applications. So far, the biotechnological potential of Spirulina subsalsa has been explored in few studies. They were mainly focused on the use of this cyanobacterium as a bioremediation agent. In our study, seven fractions from Baltic-derived S. subsalsa CCNP1310 were obtained and their cytotoxic effect on the T47D breast cancer cell line as well as inhibitory effects against elastase, trypsin, thrombin, chymotrypsin, and carboxypeptidase A were examined. Four fractions revealed a significant decrease in relative viability of cancer cells. Two inhibited the activity of chymotrypsin and one carboxypeptidase A, but at a moderate level. No effect was observed against other tested proteases. Active fractions were screened with liquid chromatography tandem mass spectrometry (LC–MS/MS) optimized for the detection of peptides, for preliminary characterization of bioactive compounds. We identified three groups of compounds which share the same fragment ions and are possibly linked with effects observed in conducted tests. Our research indicates for the first time that compounds produced by Baltic strain of S. subsalsa not only have high activity against T47D cancer cells but also seem to work selectively as they do not have strong inhibitory effect against the tested enzymes. That indicates the existing potential of the cyanobacterium to be used as a source of important cytotoxic agents.
Budget of 90Sr in the Gulf of Gdańsk (southern Baltic Sea)
Oceanologia 2018, 60(3), 256-263
Michał Saniewski*, Tamara Zalewska
Institute of Meteorology and Water Management, National Research Institute, Gdynia, Poland;
90Sr, Budget, Gulf of Gdańsk
Received 11 September 2017, Accepted 17 November 2017, Available online 1 December 2017.
In the period from 2005 to 2011 the major source of 90Sr to the Gulf of Gdańsk was the Vistula river. Its contribution was 99.7% of the total load. The main processes responsible for the decrease in 90Sr activity in the Gulf of Gdańsk were: radioactive decay (87%) and sediment deposition (13%). Average increase in the activity of 90Sr in the Gulf of Gdańsk during the study period was 5.0% (114 GBq), which was almost 2 times higher than the loss of 90Sr due to radioactive decay. In the years 1997–2015, the effective half-life of 137Cs was 9.1 years and that of 90Sr was 50.3 years. Assuming a further decrease in 137Cs and maintaining 90Sr concentrations at present level, it is expected that 90Sr will become the major anthropogenic isotope having impact on the level of radioactivity in the Gulf of Gdańsk.
Coastal hydrodynamics beyond the surf zone of the south Baltic Sea
Oceanologia 2018, 60(3), 264-276
Rafał Ostrowski1,*, Magdalena Stella1, Piotr Szmytkiewicz1, Jarosław Kapiński2, Tomasz Marcinkowski2
1Institute of Hydro-Engineering, Polish Academy of Sciences, Gdańsk, Poland;
2Maritime Institute, Gdańsk, Poland
Wind-driven current, Wave-induced nearbed oscillations, Bed shear stresses, Friction velocity, Baltic Sea, Moderate depths
Received 4 May 2017, Accepted 30 November 2017, Available online 16 December 2017.
The paper presents experimental and theoretical investigations of hydrodynamic processes in a coastal region located close to the seaward boundary of the surf zone. The analysis is based on field data collected near Lubiatowo (Poland) by measuring equipment operated simultaneously by the Institute of Hydro-Engineering of the Polish Academy of Sciences (IBW PAN) and the Maritime Institute in Gdańsk (IMG). The data consist of wind velocity and direction measured at the IBW PAN Coastal Research Station (CRS) in Lubiatowo, deep-water wave buoy records, current profiles and sea bottom sediment parameters. Mean flow velocities measured in the entire water column have almost the same direction as wind. Nearbed flow velocities induced by waves and currents, as well as bed shear stresses, are modelled theoretically to determine sediment motion regimes in the area. It appears that the nonlinear wave–current interaction generates bed shear stresses greater than those that would result from the superposition of the impacts of waves and currents separately. The paper discusses the possibility of occasional intensive sediment transport and the occurrence of distinct seabed changes at greater coastal water depths adjacent to the surf zone. It was found that this can happen under the joint influence of waves and wind-driven currents.
Parameters of wind seas and swell in the Black Sea based on numerical modeling
Oceanologia 2018, 60(3), 277-287
Boris Divinsky*, Ruben Kosyan
Shirshov Institute of Oceanology, Russian Academy of Sciences, Gelendzhik, Russia;
Wind seas, Swell, Wave climate, Black Sea, Numerical modeling, Separation of wave components
Received 16 July 2017, Accepted 30 November 2017, Available online 14 December 2017.
The main objective of our work is to estimate the climatic peculiarities of the distribution of wind sea and swell in the Black Sea. The method of our research is numerical modeling. We tuned the spectral wave model DHI MIKE 21 SW for automatic separation of the components of surface waves. We estimated the peculiarities of the spatial distribution of the power of wind seas and swell in the basin of the Black Sea in the last 10 years (2007–2016). We determined the regions of domination of wind seas and swell in the field of mixed waves.
Spatio-temporal variability of the size-fractionated primary production and chlorophyll in the Levantine Basin (northeastern Mediterranean)
Oceanologia 2018, 60(3), 288-304
1Faculty of Marine Sciences & Technology, Iskenderun Technical University, Hatay, Turkey;
2Institute of Marine Sciences, Middle East Technical University. Erdemli, Mersin, Turkey
Primary production, Chlorophyll, Picoplankton, Rhodes Gyre, Cilician Basin, Levantine Basin
Received 20 May 2017, Accepted 28 September 2017, Available online 1 November 2017.
Spatial and temporal variations in size-fractionated primary production (PP) and chl a, in relation to ambient physicochemical parameters, were studied in the three distinct ecosystems of northeastern Levantine Basin namely eutrophic Mersin Bay, mesotrophic Rhodes Gyre, and oligotrophic offshore waters. These ecosystems were visited in July and September 2012 and March and May 2013. Total primary production (TPP) rates ranged between 0.22 and 17.8 mg C m−3 h−1 within the euphotic zone, whereas depth-integrated TPP rates were in the range 21.5–348.8 mg C m−2 h−1 (mean: 105.5 ± 88 mg C m−2 h−1), with the lowest rates recorded for offshore waters. Similar spatio-temporal variations were observed in chl a concentrations, ranging from 2.3 to 117.9 mg m−2 (mean: 28.9 ± 24.9 mg m−2) in the study area. The Mersin Bay TPP rates have exceeded almost 8–12 times those measured in the offshore waters and the Rhodes Gyre; however, the chl a concentrations measured in coastal waters (0.343 mg m−3) and the Rhodes Gyre (0.308 mg m−3) were only threefold larger than the offshore values. PP and chl a were dominated by picoplankton in the study area whereas small nanoplankton, being the most active, displayed the highest assimilation ratio in offshore waters (6.8) and the Rhodes Gyre (2.8). In the upper-layer waters depleted of P (0.02–0.03 μM) of the northeastern Mediterranean, a positive correlation was observed between NO3 + NO2 and PP (and thus, chl a), which strongly suggests that reactive P and inorganic nitrogen are co-limiting factors in the production and biomass distribution of the phytoplankton community in both shelf and offshore waters.
Stokes transport in layers in the water column based on long-term wind statistics
Oceanologia 2018, 60(3), 305-311
Dag Myrhaug*, Hong Wang, Lars Erik Holmedal
Norwegian University of Science and Technology (NTNU) Trondheim, Norway;
Marine litter, Random surface gravity waves, Stokes transport velocity, Wind statistics,
Received 6 October 2017, Accepted 19 December 2017, Available online 3 February 2018.
This paper addresses the Stokes transport velocity for deep water random waves in given layers in the water column based on wind statistics, which can be estimated by the simple analytical tool provided here. Results are exemplified by using the Phillips and Pierson-Moskowitz model wave spectra together with long-term wind statistics from one location in the northern North Sea and from four locations in the North Atlantic. The results are relevant for e.g. assessing the drift of marine litter in the ocean based on, for example, global wind statistics.
Microbial enzymatic activity and its relation to organic matter abundance on sheltered and exposed beaches on the Polish coast
Oceanologia 2018, 60(3), 312-330
Aleksander M. Astel*, Katarzyna Bigus, Marcin Stec
Faculty of Mathematics and Natural Sciences, Pomeranian University, Słupsk, Poland;
keywords: The Baltic Sea, Coastal sediments, Vertical depth, The distance from the water line, Nutrients, Principal component analysis
Received 30 June 2017, Accepted 15 January 2018, Available online 3 February 2018.
The activity of lipase, aminopeptidase, α-glucosidase, β-glucosidase was correlated and assessed according to an abundance of organic matter and total forms of nutrients in beach sediments characterized by different strength of anthropopressure and degree of sheltering. 76% of the data variance was explained by six factors identified by the use of principal component analysis: (1) anthropogenic rich in N, (2) microbial enzymatic activity, (3) labile organic matter, (4) bacterial growth, (5) anthropogenic rich in P and (6) hydrolytic. Differences in secondary bacterial production according to the distance from the water line, vertical cores and seasonality are limited by the accessibility of biochemical compounds (lipids, proteins, carbohydrates, total organic carbon), total phosphorus and nitrogen. Sediments collected in exposed beaches were not as rich in organic matter as these collected in sheltered ones due to the impact of sea waves of higher energy and backward current facilitating cleaning. The highest microbial enzymatic activity was observed in the beach infilled prior to the tourist season with well-aerated sand mined from the main harbor canal. Microorganisms induce α-glucosidase synthesis to decompose hardly assimilable COM during deficit of easily assimilable PRT and CHO. The lack of easily assimilable matter activates stronger hydrolytic activity in lower layers of core sediments.
Wind wave climate of west Spitsbergen: seasonal variability and extreme events
Oceanologia 2018, 60(3), 331-343
Kacper Wojtysiak1,*, Agnieszka Herman2,*, Mateusz Moskalik1,*
1Institute of Geophysics, Polish Academy of Sciences, Warszawa, Poland;
e-mail: firstname.lastname@example.org, email@example.com
2Institute of Oceanography, University of Gdańsk, Gdynia, Poland;
Arctic, Wave climate, Hindcast, Reanalysis, Svalbard
Received 28 August 2017, Accepted 18 January 2018, Available online 6 February 2018.
Waves are the key phenomenon directly influencing coastal morphodynamics. Facing insufficient observations, wind wave climate of the west coast of Spitsbergen can be characterized on the basis of the modelled data. Here we have used the results of spectral wave models: Wave Watch III (WW3) hindcast and WAM in ERA-interim (ERAi) reanalysis. We have observed the presence of seasonal cycle with difference of up to 1 m between significant wave heights in summer and winter. In wave-direction analysis we have noticed the southwestern swell component of remarkably narrow width, thus we expect unidirectional swell impact on the coastline. Extreme events analysis revealed that storms occur mainly in winter, but the most energetic ones (significant wave height of up to 9.5 m) occur in spring and autumn. We have identified positive trends in storms’ frequency (2 storms per decade) and storms’ total duration (4 days per decade) on the south of the study area. More storms can result in the increase of erosion rate on the south-western coasts of Spitsbergen, but this change may be highly dependent on the sea ice characteristics. Wave heights of wind sea and swell are correlated with the relevant atmospheric circulation indices, especially the North Atlantic Oscillation. In the recent decade, the correlation is stronger with WW3 than with ERAi data, at some locations explaining over 50% (over 30%) of the total variance of wind sea (swell) wave heights. In ERAi data, the relationship with circulation indices seems sensitive to the length of the analysis period.
Climate-related trends and meteorological conditions in the Porsanger fjord, Norway
Oceanologia 2018, 60(3), 344-366
Agata Cieszyńska1,2,*, Małgorzata Stramska2,1,*
1Department of Earth Sciences, Szczecin University, Szczecin, Poland;
e-mail: firstname.lastname@example.org, email@example.com
2Institute of Oceanology, Polish Academy of Sciences, Sopot, Poland;
Arctic, Norwegian fjord, Marine meteorology, Climate change, Seasonal variability
Received 25 July 2017, Accepted 22 January 2018, Available online 10 February 2018.
Climate-related trends and meteorological conditions in the Porsanger fjord, in the vicinity of the Barents Sea, have been analyzed. Meteorological data include wind speed and direction, air temperature (AT) and precipitation from Era-Interim reanalysis (1986–2015) as well as local observations (2006–2015) from Honningsvaag and Lakselv. Statistically significant trends in annual AT means are 0.0485°C year−1 near the fjord mouth and 0.0416°C year−1 near the fjord head. Wind speed and precipitation data do not reveal any definite trends. Statistical analysis confirms the significant spatial variability of meteorological conditions in the fjord. For example, there are large differences in the annual AT cycle, with respective monthly means for January and July of −8.4 and 12.6°C at Lakselv (fjord head) and −2.5 and 10.1°C at Honningsvaag (fjord mouth). Strong wind events (>12 m s−1) are more frequent at Honningsvaag than at Lakselv. The annual cycle is characterized by stronger winds in winter and seasonality of wind direction. At Lakselv, the dominant wind directions in summer are: N, NNW and S and in winter: S and SSE. At Honningsvaag, the wind directions in summer present strong variability, no fixed pattern being pronounced, whilst the dominant sectors in winter are: S and SSW. Daily cycles in AT and wind speed are also observed. Precipitation at a given location can change by about 30% year-on-year and varies spatially. Estimates of terrigenous water discharge (derived from the E-HYPE model) reveal a seasonal cycle with the maximum discharge in late spring/early summer.
The effects of cyanobacterial blooms on MODIS-L2 data products in the southern Caspian Sea
Oceanologia 2018, 60(3), 367-377
Karim Naghdi1,*, Masoud Moradi1, Keivan Kabiri1, Majid Rahimzadegan2
1Department of Marine Remote Sensing, Iranian National Institute for Oceanography and Atmospheric Science, Tehran, Iran;
2Department of Water Resources, Civil Eng. Faculty, K. N. Toosi University of Technology, Tehran, Iran;
Remote sensing, Cyanobacterial index, Floating algae index, Chlorophyll-a, Fluorescence line height
Received 25 July 2017, Accepted 9 February 2018, Available online 6 March 2018.
MODIS satellite imageries with minimal cloud cover (<25%) were used to extract cyanobacteria index, floating algea index, fluorescence line height, chlorophyll-a and sea surface temperature products, for seven days concurrent with blooms. The results showed a positive correlation between cyanobacteria index and chlorophyll-a (R = 0.74, p ≤ 0.05 and R = 0.75, p ≤ 0.05 for 2005 and 2010 respectively), and a negative correlation between the cyanobacteria index and fluorescence line height (R = −0.74, p ≤ 0.05 and R = −0.93, p ≤ 0.005 for 2005 and 2010 respectively). Further analysis showed that considering Fluorescence Line Height is not sufficient to detect the cyanobacterial blooms in the offshore area. However, the results indicated a weak correlation between cyanobacteria index and floating algae index (R = −0.42, p = 0.34 and R = −0.47, p = 0.29 for 2005 and 2010 respectively). The results also indicated that the irregular increases in the cyanobacteria index and chlorophyll-a in the study region was an operational index for the incidence of cyanobacterial bloom, where the surface wind speed and temperature conditions were <4 m s−1 and ≥30°C, respectively. Finally, a linear model was defined for monitoring, which determines occurrence or non-occurrence of cyanobacteria bloom based on daily monitoring of the changes of products. In order to evaluate the proposed model, its efficiency was tested on datasets at different times and locations, and the results were consistent with field reports, as expected.
Impact of climate change on the Curonian Lagoon water balance components, salinity and water temperature in the 21st century
Oceanologia 2018, 60(3), 378-389
Darius Jakimavičius*, Jūratė Kriaučiūnienė, DianaŠarauskienė
Laboratory of Hydrology, Lithuanian Energy Institute, Kaunas, Lithuania;
Curonian Lagoon, RCP scenarios, HBV modelling software, Water salinity, Water temperature
Received 6 July 2017, Accepted 14 February 2018, Available online 1 March 2018.
The Curonian Lagoon is a shallow water body connected to the Baltic Sea by a narrow navigable strait, which enables an exchange of water of different salinity. The projected climate change together with the peculiarities of mixing water will undoubtedly alter hydrological regime of this lagoon. The study uses three climate model outputs under four RCP scenarios, four sea level rise scenarios and hydrological modelling in order to project the extent to which water balance components, salinity and temperature may change in the future. In order to simulate river inflow, the Nemunas River hydrological model was created using HBV software. In general, the changes of the lagoon water balance components, salinity and temperature are expected to be more significant in 2081–2100 than in 2016–2035. It was estimated that in the reference period (1986–2005) the river inflow was 22.1 km3, inflow from the sea was 6.8 km3, salinity (at Juodkrantė) was 1.2 ppt and average water temperature of the lagoon was 9.2°C. It was projected that in 2081–2100 the river inflow may change from 22.1 km3 (RCP2.6) to 15.9 km3 (RCP8.5), whereas inflow from the sea is expected to vary from 8.5 km3 (RCP2.6) to 11.0 km3 (RCP8.5). The lagoon salinity at Juodkrantė is likely to grow from 1.4 ppt (RCP2.6) to 2.6 ppt (RCP8.5) by the end of the century due to global sea level rise and river inflow decrease. The lagoon water temperature is projected to increase by 2–6°C by the year 2100.
Ecosystem of the Polish part of the Vistula Lagoon from the perspective of alternative stable states concept, with implications for management issues
Oceanologia 2018, 60(3), 390-404
Department of Fisheries Oceanography and Marine Ecology, National Marine Fisheries Research Institute, Gdynia, Poland;
Baltic Sea, Coastal management, Regime shift, Food-web interactions, Drivers
Received 21 November 2017, Accepted 21 February 2018, Available online 7 March 2018.
The alternative stable states concept finds broad application in reference to both terrestrial and aquatic ecosystems. For some reason, attempts to implement the concept to explain processes observed in estuaries and Baltic lagoons are very rare. Based on information included in publications issued over the last 60 years, three co-existing states were designated within the strongly elongated basin the Vistula Lagoon, namely: phytoplankton-dominated (Middle Basin), macrophyte-dominated (Elbląg Bay), and transition state balancing between the two former ones (West Basin). Regions of the lagoon representing such states are similar in terms of nutrient concentrations, but they considerably differ in terms of: exposure to wind and wave action, salinity, anthropogenic impact, and multi-level top-down regulations. The paper discusses the role of such drivers, responsible for both the maintenance of a given state, and the past transition into the present alternative state. Moreover, it presents chances for the improvement of the situation, as well as threats which can undermine them.
Comparison of the burial rate estimation methods of organic and inorganic carbon and quantification of carbon burial in two high Arctic fjords
Oceanologia 2018, 60(3), 405-418
Katarzyna Koziorowska*, Karol Kuliński, Janusz Pempkowiak
Institute of Oceanology Polish Academy of Sciences, Sopot, Poland;
Spitsbergen, Carbon deposition, Pore water, Dissolved carbon species, Return flux, Carbon accumulation, Sedimentary carbon
Received 7 February 2018, Accepted 23 February 2018, Available online 12 March 2018.
Quantifying the burial of organic carbon (OC) and inorganic carbon (IC) species in marine sediments contribute to a better understanding of carbon cycle. This is especially important in the Arctic, where carbon deposition is relatively high and expected to change with climate warming. This study aimed to quantify the burial rates of OC and IC in the sediments of two high-latitude fjords – Hornsund and Kongsfjorden (European Arctic). Comparison of the results from three methods quantifying carbon burial in marine sediments was carried out.
Sediment cores, pore water, and over-bottom water samples were analyzed for OC and IC. The burial rates were established by considering: carbon deposition to sediments minus carbon return flux, carbon deposited to sediments 80–100 years ago and carbon deposited to sediments recently. The radiolead method was employed for sediment dating. Carbon return flux was obtained using dissolved carbon species concentrations in pore water and over-bottom water.
Sediment linear and mass accumulation rates in the fjords were 0.12–0.20 cm y−1 and 1160–2330 g m−2 y−1. The OC burial rates were 19.3–30.3 g OC m−2 y−1 in Hornsund and 5.7–10.0 g OC m−2 y−1 in Kongsfjorden. IC burial was taken as equal to IC deposition and ranged from 10.7 to 20.8 g IC m−2 y−1 in Hornsund and 19.4–45.7 g IC m−2 y−1 in Kongsfjorden. The “return flux” model seems most appropriate for carbon burial rate studies. The data demonstrated that OC burial dominates in Hornsund, while in Kongsfjorden, IC burial is more important.
Characterization of light absorption coefficient of red Noctiluca scintillans bloom in the South Eastern Arabian Sea
Oceanologia 2018, 60(3), 419-425
Sudheeshan Sushama Shaju1,*, Raghunadha Rao Akula1, Thajudeen Jabir2
1Naval Physical and Oceanographic Laboratory (DRDO), Kochi, India;
2Department of Marine Biology Microbiology and Biochemistry, Cochin University of Science and Technology, Kochi, India
Noctiluca scintillans, Phytoplankton absorption coefficient, Upwelling, Oil sardine, South Eastern Arabian Sea (SEAS)
Received 27 June 2017, Accepted 20 December 2017, Available online 8 January 2018.
The red Noctiluca scintillans bloom was observed off Cochin in the South Eastern Arabian Sea (SEAS), affecting a very large area during July–August 2016. The surface water samples from the bloom region were collected to study the physical, biological and light absorption characteristics. The bloom affects the food chain by their voracious predation on the species of both first and second trophic levels. The N. scintillans cell density during the bloom was estimated at 4.73 × 105 cells l−1. In the phytoplankton absorption coefficient spectra, the accessory pigments displayed peaks in the 488–558 nm regions, which represent the characteristic carotenoid pigment (red colored pigment) for the bloom of red Noctiluca. Signature of the coastal upwelling was found from the salinity and temperature distribution, which was measured prior to the bloom occurrence. From the sea surface temperature (SST), it is also confirmed the presence of fresh water from the Cochin estuary. Increased productivity near coastal region, along with episodic events of strengthening of the upwelling, favors the proliferation of smaller diatoms. The plankton succession from smaller diatoms to larger diatoms and dinoflagellates, favors the proliferation of the red Noctiluca. The occurrence of blooms of red N. scintillans, which feed on phytoplankton, mainly diatoms, and other dinoflagellates, could be a threat to larvae of oil sardine during the upwelling period, and may negatively impact on the commercially important fishery of oil sardine, in this region.
First record of the deep-water shark Etmopterus spinax (Chondrichthyes: Etmopteridae) from the southern Baltic Sea (Pomeranian Bay)
Oceanologia 2018, 60(3), 426-430
Beata Więcaszek*, Ewa Sobecka*, Remigiusz Panicz*, Sławomir Keszka*, Klaudia Górecka*, Angelika Linowska*,
West Pomeranian University of Technology in Szczecin, Szczecin, Poland;
Etmopterus spinax, Anisakis simplex, Pomeranian Bay, Southern Baltic Sea, Inflow from the North Sea
Received 29 September 2017, Accepted 1 February 2018, Available online 14 February 2018.
Etmopterus spinax is a deep-sea shark species that inhabits the northeast Atlantic and the western Mediterranean Sea. Skagerrak and Kattegat are reported to be part of the distribution of the species, but it has never been noted in the southern Baltic. Lacking any commercial value and commonly discarded in trawl and longline fisheries, E. spinax has been poorly studied. We reported on the first record of one specimen of E. spinax caught in the Pomeranian Bay on October 13, 2016 at a depth of 10 m. It was a female measuring 42.7 cm in total length. The morphological examination of the specimen was supported with COI barcode analysis, whereas species assignment to the population of origin was conducted based on a control region (CR) sequence of mtDNA. COI and CR sequence searches against GeneBank confirmed its identity as E. spinax and revealed that the specimen shared identical haplotypes with fish from populations in the Azores, Rockall Trough, and west of Ireland in the northeast Atlantic. The stomach contents, parasitic fauna, and hepatosomatic index of the individual were also examined. Only one L3 larval Anisakis simplex nematode specimen was collected from the stomach lumen of the shark. The specimen could have arrived in the Pomeranian Bay along with an inflow from the North Sea. In December 2014, a strong Major Baltic Inflow brought large amounts of water into the Baltic Sea, followed by some inflows of moderate intensity.