Oceanologia No. 61 (2) / 19
Original research article
Effects of environmental variables on midsummer dinoflagellate community in the Neva Estuary (Baltic Sea): Mikhail Golubkov, Vera Nikulina, Sergey Golubkov
Trophic connectivity between intertidal and offshore food webs in Mirs Bay, China: Jiajia Ning, Feiyan Du, Xuehui Wang, Lianggen Wang, Yafang Li
An eco-friendly strategy using flax/polylactide composite to tackle the marine invasive sponge Celtodoryx ciocalyptoides (Burton, 1935): Charline Gentric, Pierre Sauleau
Life in sympatry: coexistence of native Eurytemora affinis and invasive Eurytemora carolleeae in the Gulf of Finland (Baltic Sea): Natalia Sukhikh, Anissa Souissi, Sami Souissi, Anne-Catherine Holl, Nikolaos V.Schizas, Victor Alekseev
Seasonal variations in the abundance and sinking flux of biogenic silica in Daya Bay, northern South China Sea: Xiufeng Zhao, Weifeng Yang, Haoyang Ma, Junjie Li, Min Chen, Ziming Fang, Xiao Zhang, Jian Zeng, Yusheng Qiu, Minfang Zheng
Erosion and deposition processes from field experiments of hydrodynamics in the coastal mangrove area of Can Gio, Vietnam: Hoa Tien Le Nguyen, Hong Phuoc Vo Luong
The response of cyclonic eddies to typhoons based on satellite remote sensing data for 2001–2014 from the South China Sea: Fangjie Yu, Qiongqiong Yang, Ge Chen, Qiuxiang Li
A cost-effective method for estimating long-term effects of waves on beach erosion with application to Sitia Bay, Crete: Flora E. Karathanasi, Kostas A. Belibassakis
Amphipods in estuarine and marine quality assessment – a review
Oceanologia 2019, 61(2), 179-196
Weronika Podlesińska1,*, Henryka Dąbrowska2
1Gdynia Aquarium, National Marine Fisheries Research Institute (NMFRI), Gdynia, Poland;
2Department of Food and Environmental Chemistry, NMFRI, Gdynia, Poland
Ecotoxicology, Marine sediments, Amphipods, Corophium spp., Bioassays
Received 4 June 2018, Accepted 27 September 2018, Available online 17 October 2018.
Amphipods are a diverse and important group of invertebrates contributing to the functioning of aquatic ecosystems. In spite of their variety, many species of amphipods share important biological and ecological characteristics that make them suitable test organisms for assessment of the ecological quality of estuarine and marine sediments. Their pertinence as test organism includes ecological relevance, close association with sediments, sensitivity to environmental contaminants, and amenability for culture and experimentation. Amphipod bioassays are used to examine the effect of exposure to contaminants, as well as to assess whole sediment quality, improve bioassay methods, develop more sensitive endpoints, and compare sensitivity and utility of species in environmental quality assessment. This work reviews the developments in this area of research over the last decades, focusing on European amphipods. The most often used species, the type of bioassays and endpoints investigated, confounding factors influencing the bioassays outcome, and the main applications of the bioassays have been presented. This review also addresses some aspects of amphipod biology that are relevant for bioassay methods and results analysis.
Original research article
Effects of environmental variables on midsummer dinoflagellate community in the Neva Estuary (Baltic Sea)
Oceanologia 2019, 61(2), 197-207
Mikhail Golubkov*, Vera Nikulina, Sergey Golubkov
Zoological Institute of Russian Academy of Sciences, St. Petersburg, Russian Federation;
Gulf of Finland, Phytoplankton, Mixotrophy, Eutrophication, Climate change
Received 13 June 2018, Accepted 19 September 2018, Available online 4 October 2018.
Dinoflagellates account for most of the harmful phytoplankton species but relatively little is known about the specific responses of different species to environmental variables. 21 dinoflagellate species were recorded in the plankton of the Neva Estuary since the mid-19th century. 14-year long data of midsummer dinoflagellate biomass was statistically analyzed in the Neva Estuary to show the changes in dinoflagellate species in relation to environmental factors. Biomasses of Dinophysis norvegica (Clapared & Lachmann 1859), Prorocentrum lima ((Ehrenberg) F.Stein 1878) and Peridinium aciculiferum (Lemmermann 1900) had very similar positive relationships with salinity, temperature, phosphorus and suspended particulate organic matter concentrations while the biomass of the other common species Peridinium cinctum ((Müller) Ehrenberg 1832) and Peridinium sp. mostly showed quite opposite trends. Climate fluctuations leading to changes in the environmental variables could significantly affect the composition and productivity of the dinoflagellate community. Biomass of Glenodinium sp. and Peridinium sp. positively correlated with primary production and biomass and chlorophyll a concentration, but did not show a positive relationship with phosphorus. This may be due to the fact that these species in the conditions of the Neva Estuary, apparently, are more consumers than producers of organic matter, feeding on algae and cyanobacteria of phytoplankton. Therefore, to interpret the relationships between the dinoflagellate biomass and environmental variables one should take into account that the species of this group is characterized by mixotrophy and, consequently, their biomass may depend not only on the conditions of autotrophic, but also heterotrophic nutrition.
Trophic connectivity between intertidal and offshore food webs in Mirs Bay, China
Oceanologia 2019, 61(2), 208-217
Jiajia Ning1,2,3, Feiyan Du1,2,3,*, Xuehui Wang1,2,3, Lianggen Wang1,2,3, Yafang Li1,2,3
1South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, China;
2Guangdong Provincial Key Laboratory of Fishery Ecology and Environment, Guangzhou, China
3Key Laboratory of South China Sea Fishery Resources Exploitation & Utilization, Ministry of Agriculture and Rural Affairs, Guangzhou, China
Food webs, Trophic connectivity, Carbon pathways, Stable isotopes, Mirs Bay
Received 2 August 2018, Accepted 11 October 2018, Available online 22 October 2018.
Trophic interactions are common worldwide, both within and between ecosystems. This study elucidated the trophic connectivity between intertidal and offshore zone, in Mirs Bay, China. The contributions of offshore suspended particulate organic matter (SPOM), intertidal macroalgae and epiphytes to consumer biomass were assessed, and the trophic pathways were identified through the use of stable isotope ratios of carbon (δ13C) and nitrogen (δ15N) of basal sources and consumers. Mean δ13C values of basal sources had a wide range (−19.6‰ to −11.8‰) and were generally well separated in Mirs Bay. The average δ13C of consumers in Mirs Bay ranged from −19.2‰ to −11.8‰, reflecting a carbon source integrated from different primary producer signals. IsoSource model solutions indicated consumers assimilated organic carbon from a mixture of basal sources. Offshore SPOM carbon was the primary carbon source supporting most consumers in both intertidal and offshore zones. Intertidal macroalgae and epiphytes also accounted for a large fraction for some consumers. δ15N data indicated 5 trophic levels in Mirs Bay. Intertidal consumers, except for Capitulum mitella, had a TP (trophic position) between 2 and 3, and mainly included filter-feeders and grazers. In contrast, almost all offshore consumers had a TP of between 3 and 4 except for filter-feeders (zooplankton), planktivores (Clupanodon punctatus and Sardinella aurita) and piscivores (Gymnura japonica). The basal sources fueled consumers through two trophic pathways, each of which involved organisms of both intertidal and offshore zones, implying trophic connectivity between them in the Mirs Bay ecosystem.
An eco-friendly strategy using flax/polylactide composite to tackle the marine invasive sponge Celtodoryx ciocalyptoides (Burton, 1935)
Oceanologia 2019, 61(2), 218-226
Charline Gentric, Pierre Sauleau*,
University Bretagne-Sud, Lorient, France;
Artificial substrate, Biocomposite, Celtodoryx ciocalyptoides, Marine invaders, Polylactide
Received 19 March 2018, Accepted 14 October 2018, Available online 26 October 2018.
Discovered in the 1990s in the river of Etel (Morbihan, France), the marine invasive sponge Celtodoryx ciocalyptoides originating from the Chinese Yellow Sea is now well implanted on concrete pilings inside the Etel marina (Morbihan, France). Novel eco-friendly strategies are urgently needed in order to limit its adhesion on concrete and the risk of dispersal outside the marina. In this study, the anti-settlement and anti-attachment properties of flax/PLA, a biocomposite made of polylactide reinforced with flax fibres, were evaluated on sponge propagules’ behaviour. First, flax/PLA panels were immersed into the Etel marina for six years. The coverage onto PLA panels of marine invertebrates was estimated twice a year. In a second step, PLA panels were used as artificial support for invasive sponge transplants. In comparison, specimens were transplanted in mesh bags. Sponge weight increase was measured twice a year. Results indicated that the occurrence of the invasive sponge was delayed for two years on biocomposite in comparison with concrete. At the end of the six-year study, macrofouling by marine invertebrates did not exceed 70% of the surface of the panels and no C. ciocalyptoides specimens were observed. Once transplanted on PLA panels, sponge specimens were able to survive the first year without growing. After two years, none of the transplants survived while specimens in mesh bags increased their weight by 100%. These findings highlight the potential interest of biocomposite in the development of coastal and marine infrastructures.
Life in sympatry: coexistence of native Eurytemora affinis and invasive Eurytemora carolleeae in the Gulf of Finland (Baltic Sea)
Oceanologia 2019, 61(2), 227-238
Natalia Sukhikh1,*, Anissa Souissi2, Sami Souissi2, Anne-Catherine Holl3, Nikolaos V. Schizas4, Victor Alekseev1
1Zoological Institute, Russian Academy of Science, Saint Petersburg, Russia;
e-mail: Susikh1@mail.ru, email@example.com
2Lille University, CNRS, ULCO, LOG, Wimereux, France;
e-mail: firstname.lastname@example.org, Sami.Souissi@univ-lille1.fr
3Lille University of Science and Technology, CNRS, Villeneuve d’Ascq Cedex, France;
4Department of Marine Sciences, University of Puerto Rico, Mayagüez, Puerto Rico;
Eurytemora species, Copepoda, Zooplankton, Invasive and native species, Gulf of Finland
Received 18 June 2018, Accepted 2 November 2018, Available online 22 November 2018.
The invasion of exotic species into native ecosystems is becoming a crucial issue in global biology. Over the last ten years, at least 45 invasions of aquatic species have been reported in the eastern part of the Gulf of Finland; the majority of them were introduced through ballast water. Recently, invasion of the estuarine calanoid copepod Eurytemora carolleeae (Temoridae), originating from North America, has been reported in several European estuaries and particularly in the Gulf of Finland. This species is morphologically very similar to the native Eurytemora affinis, but it is easily discriminated by molecular markers. In this study, we monitored the distribution area of the invasive copepod species in European waters, as well as the population structure of (native) E. affinis and (invasive) E. carolleeae, from 2006 to 2018 in the Gulf of Finland. The population density of E. affinis was significantly higher, compared to E. carolleeae, during most of the study period. The only exception was Neva Bay in 2010, wherein the invasive species dominated possibly due to high temperatures and differences in the levels of fish predation. The reproductive performance of E. carolleeae was also higher than that of E. affinis. These results show different population dynamics between the two species. It was revealed that invasive E. carolleeae develops in some of the very same habitats as native E. affinis, thereby potentially becoming a significant component of the zooplankton in the studied area. Moreover, invader has the potential to displace native E. affinis.
Seasonal variations in the abundance and sinking flux of biogenic silica in Daya Bay, northern South China Sea
Oceanologia 2019, 61(2), 239-251
Xiufeng Zhao, Weifeng Yang*, Haoyang Ma, Junjie Li, Min Chen, Ziming Fang, Xiao Zhang, Jian Zeng, Yusheng Qiu, Minfang Zheng
State Key Laboratory of Marine Environmental Science and College of Ocean and Earth Sciences, Xiamen University, Xiamen, China;
Biogenic silica, Dissolved silicate, Sinking flux, Thorium, Daya Bay
Received 25 August 2018, Accepted 14 November 2018, Available online 23 November 2018.
Coastal seas account for >50% of the biogenic silica (BSi) production in marine environments. However, BSi sinking is poorly understood. Here, seasonal variations in the abundance and sinking flux of BSi were investigated in Daya Bay, in the northern South China Sea. The highest BSi concentrations occurred in summer, averaging 8.04 ± 5.48 μmol L−1 (±SD), followed by autumn (5.51 ± 3.11 μmol L−1) and spring (3.76 ± 3.06 μmol L−1). The lowest BSi concentration of 2.93 ± 1.34 μmol L−1 was observed in winter. Based on 234Th/238U disequilibria, the average BSi sinking fluxes were 7.08 ± 8.62, 10.01 ± 13.95, and 8.30 ± 13.06 mmol Si m−2 d−1 in spring, summer, and autumn, respectively. The lowest flux of 4.19 ± 3.98 mmol Si m−2 d−1 was measured in winter. Together with nitrogen fluxes, the Si:N sinking ratios were 0.8:1.0, 1.5:1.0, 1.6:1.0, and 1.4:1.0 in spring, summer, autumn, and winter, respectively, indicating that particle sinking induces the faster removal of Si compared to N in Daya Bay.
Erosion and deposition processes from field experiments of hydrodynamics in the coastal mangrove area of Can Gio, Vietnam
Oceanologia 2019, 61(2), 252-264
Hoa Tien Le Nguyen,*, Hong Phuoc Vo Luong
Department of Oceanology, Meteorology and Hydrology, University of Science, Vietnam National University, Ho Chi Minh City, Vietnam;
e-mail: email@example.com, firstname.lastname@example.org
Hydrodynamics, Suspended sediment concentrations (SSCs), Erosion, Mangrove forests, Can Gio Mangrove Biosphere Reserve
Received 16 August 2018, Accepted 23 November 2018, Available online 1 December 2018.
Studying hydrodynamic processes is necessary for understanding the sediment erosion–deposition mechanism in mangrove areas. The hydrodynamic effects within the mangrove area of the Dong Tranh Estuary in the Can Gio Mangrove Biosphere Reserve in Ho Chi Minh City (HCMC), Vietnam are very complicated and are caused by the mixed impacts of waves, tides, currents and suspended sediment concentrations (SSCs). In this study, the measurements of hydrodynamics such as waves, currents and SSCs were conducted in the dry (Feb. 2012) and wet (Jun. 2014) seasons. Three stations were set up within the estuary, mud-flat and mangrove forest. The analysed results showed that the hydrodynamics in all three stations were strongly influenced during the first dry monsoon season and the next wet one. The waves were the main factor during the dry season and contributed more SSC turbulence in the mud-flat, potentially causing erosion at the study site. Meanwhile, the current velocities in both the estuary and mud-flat sites were major factors during the wet season. In the mangrove forest, the SSC during the dry season changed due to the tidal cycle. Additionally, two measurements for the change in the topographies and shorelines were conducted from 2014 to 2017. The results show that the study site has been eroding rapidly (0.61 m month−1). Although this study shows a soil retention role for the mangrove forests, the wave energy dissipation occurs mainly within the mud-flat due to the bottom topography. The study site is proven to be eroding.
The response of cyclonic eddies to typhoons based on satellite remote sensing data for 2001–2014 from the South China Sea
Oceanologia 2019, 61(2), 265-275
Fangjie Yu1,2, Qiongqiong Yang1, Ge Chen1,2,*, Qiuxiang Li1
1College of Information Science and Engineering, Ocean University of China, Qingdao, PR China;
2Laboratory for Regional Oceanography and Numerical Modeling, Qingdao National Laboratory for Marine Science and Technology, Qingdao, PR China
keywords: Tropical cyclones, Mesoscale eddy, Eddy kinetic energy
Received 19 August 2018, Accepted 26 November 2018, Available online 11 December 2018.
Eddies are known to be affected by typhoons, and in recent years, the general three-dimensional structure, as well as features of the spatial and temporal distributions of eddies have been determined. However, the type of eddy that is most likely to be affected by a typhoon remains unclear. In this paper, quantitative and qualitative methods were used to study the eddies that are most sensitive to upper-ocean tropical cyclones (TCs) from the perspective of eddy characteristics, and the quantitative results showed that not all eddies were enhanced under the influence of typhoons. Enhancement of the eddy amplitude (Amp), radius (Rad), area (A), or eddy kinetic energy (EKE) accounted for 92.3% of the total eddy within the radius of the typhoon. Qualitative analyses showed the following: First, eddies located on different sides of the typhoon tracks were differently affected, as eddies on the left side were more intensely affected by the typhoon than eddies on the right side, and second, eddies with short lifespans or small radii were more susceptible to the TCs.
A cost-effective method for estimating long-term effects of waves on beach erosion with application to Sitia Bay, Crete
Oceanologia 2019, 61(2), 276-290
Flora E. Karathanasi1,2,*, Kostas A. Belibassakis1
1School of Naval Architecture & Marine Engineering, National Technical University of Athens, Athens, Greece;
2Institute of Oceanography, Hellenic Centre for Marine Research, Anavyssos, Greece
Beach erosion, Bed level evolution, Wave/current modelling, Shields criterion, Sitia-Crete coast
Received 24 July 2018, Accepted 5 December 2018, Available online 19 December 2018.
Considering the significant role of beaches for the sea environment and welfare of coastal communities, a variety of process-based models are applied in order to examine and understand the interaction of hydrodynamic processes with seabed material at different time scales. However, a long-term view of this interaction requires a great amount of computational time. In this work a cost-effective methodology is proposed to surpass this shortcoming and estimate bed level evolution. The technique is relied on an objective criterion to assess spectral wave time series of wave height, period and direction and identify the wave conditions that contribute to the initiation of sediment movement. After implementing the so-called Shields criterion, the full wave climate is reduced to two classes of representative wave conditions: the over-critical ones, mainly responsible for long-term erosion, and the sub-critical wave conditions. By applying a well-known process-based model, the representative wave conditions are used as input for the wave-current-sediment transport simulation and rates of bed level changes are obtained, on the basis of which the long-term effects of waves on beach erosion are estimated. Taking into account that erosion is a threatening phenomenon along the sandy beaches of Mediterranean Sea, the present method is demonstrated at a sandy coast of Sitia Bay, Crete. The bed levels derived from the proposed methodology and the full time series are compared. The results indicate reasonable agreement at the selected locations with deviations under 7%, and conformity of the tendency of seabed evolution, rendering the new methodology a useful tool.