scholarly journals Mesozooplankton community development at elevated CO<sub>2</sub> concentrations: results from a mesocosm experiment in an Arctic fjord

2012 ◽  
Vol 9 (8) ◽  
pp. 11479-11515 ◽  
Author(s):  
B. Niehoff ◽  
N. Knüppel ◽  
M. Daase ◽  
J. Czerny ◽  
T. Boxhammer
Keyword(s):  
Fossil Fuels ◽  
Cold Water ◽  
Mesh Size ◽  
Experimental Period ◽  
Sediment Traps ◽  
Taxonomic Composition ◽  
Marine Biota ◽  
Mesozooplankton Community ◽  
Co2 Concentrations ◽  
Arctic Fjord

Abstract. The increasing CO2 concentration in the atmosphere caused by burning fossil fuels leads to increasing pCO2 and decreasing pH in the world oceans. These changes may have severe consequences for marine biota, especially in cold-water ecosystems due to higher solubility of CO2. However, studies on the response of mesozooplankton communities to elevated pCO2 are yet lacking. In order to test whether abundance and taxonomic composition change with pCO2, we have sampled nine mesocosms, which were deployed in Kongsfjorden, an Arctic fjord at Svalbard, and were adjusted to eight CO2 concentrations, initially ranging from 185 μatm to 1420 μatm. Samples were taken weekly over a six-week period with an Apstein net (55 μm mesh size) in all mesocosms and the surrounding fjord. In addition, sediment trap samples, taken every second day in the mesocosms, were analyzed to account for losses due to vertical migration and mortality. The taxonomic analysis revealed that meroplanktonic larvae (cirripeds, polychaetes, bivalves, gastropod, and decapods) dominated in the mesocosms while copepods (Calanus spp., Oithona similis, Acartia longiremis and Microsetella norvegica) were found in lower abundances. In the fjord copepods prevailed for most of our study. With time, abundance and taxonomic composition developed similarly in all mesocosms; the pCO2 had no significant effect on the overall community structure. However, single taxa responded to elevated CO2 concentrations. The ratio of cirripedia nauplii to cypris larvae, the next developmental stage, in the sediment traps averaged over the entire experiment increased with pCO2 and this suggests that increased pCO2 may have delayed their development. Also, the number of bivalves, averaged over the experimental period, decreased significantly with increasing pCO2. The nature of the CO2 effect, either direct or indirect, remains open and needs to be addressed in future.

scholarly journals Mesozooplankton community development at elevated CO<sub>2</sub> concentrations: results from a mesocosm experiment in an Arctic fjord

2013 ◽  
Vol 10 (3) ◽  
pp. 1391-1406 ◽  
Author(s):  
B. Niehoff ◽  
T. Schmithüsen ◽  
N. Knüppel ◽  
M. Daase ◽  
J. Czerny ◽  
...  
Keyword(s):  
Fossil Fuels ◽  
Cold Water ◽  
World Ocean ◽  
Mesh Size ◽  
Co2 Concentration ◽  
Taxonomic Composition ◽  
Marine Biota ◽  
Mesozooplankton Community ◽  
Oithona Similis ◽  
Arctic Fjord

Abstract. The increasing CO2 concentration in the atmosphere caused by burning fossil fuels leads to increasing pCO2 and decreasing pH in the world ocean. These changes may have severe consequences for marine biota, especially in cold-water ecosystems due to higher solubility of CO2. However, studies on the response of mesozooplankton communities to elevated CO2 are still lacking. In order to test whether abundance and taxonomic composition change with pCO2, we have sampled nine mesocosms, which were deployed in Kongsfjorden, an Arctic fjord at Svalbard, and were adjusted to eight CO2 concentrations, initially ranging from 185 μatm to 1420 μatm. Vertical net hauls were taken weekly over about one month with an Apstein net (55 μm mesh size) in all mesocosms and the surrounding fjord. In addition, sediment trap samples, taken every second day in the mesocosms, were analysed to account for losses due to vertical migration and mortality. The taxonomic analysis revealed that meroplanktonic larvae (Cirripedia, Polychaeta, Bivalvia, Gastropoda, and Decapoda) dominated in the mesocosms while copepods (Calanus spp., Oithona similis, Acartia longiremis and Microsetella norvegica) were found in lower abundances. In the fjord copepods prevailed for most of our study. With time, abundance and taxonomic composition developed similarly in all mesocosms and the pCO2 had no significant effect on the overall community structure. Also, we did not find significant relationships between the pCO2 level and the abundance of single taxa. Changes in heterogeneous communities are, however, difficult to detect, and the exposure to elevated pCO2 was relatively short. We therefore suggest that future mesocosm experiments should be run for longer periods.

scholarly journals Sacrificial amphiphiles: Eco-friendly chemical herders as oil spill mitigation chemicals

2015 ◽  
Vol 1 (5) ◽  
pp. e1400265 ◽  
Author(s):  
Deeksha Gupta ◽  
Bivas Sarker ◽  
Keith Thadikaran ◽  
Vijay John ◽  
Charles Maldarelli ◽  
...  
Keyword(s):  
Crude Oil ◽  
Oil Spill ◽  
Oil Spills ◽  
Cold Water ◽  
Marine Ecosystem ◽  
Hot Water ◽  
Sea Surface ◽  
Marine Biota ◽  
Polar Group ◽  
Branched Chain

Crude oil spills are a major threat to marine biota and the environment. When light crude oil spills on water, it forms a thin layer that is difficult to clean by any methods of oil spill response. Under these circumstances, a special type of amphiphile termed as “chemical herder” is sprayed onto the water surrounding the spilled oil. The amphiphile forms a monomolecular layer on the water surface, reducing the air–sea surface tension and causing the oil slick to retract into a thick mass that can be burnt in situ. The current best-known chemical herders are chemically stable and nonbiodegradable, and hence remain in the marine ecosystem for years. We architect an eco-friendly, sacrificial, and effective green herder derived from the plant-based small-molecule phytol, which is abundant in the marine environment, as an alternative to the current chemical herders. Phytol consists of a regularly branched chain of isoprene units that form the hydrophobe of the amphiphile; the chain is esterified to cationic groups to form the polar group. The ester linkage is proximal to an allyl bond in phytol, which facilitates the hydrolysis of the amphiphile after adsorption to the sea surface into the phytol hydrophobic tail, which along with the unhydrolyzed herder, remains on the surface to maintain herding action, and the cationic group, which dissolves into the water column. Eventual degradation of the phytol tail and dilution of the cation make these sacrificial amphiphiles eco-friendly. The herding behavior of phytol-based amphiphiles is evaluated as a function of time, temperature, and water salinity to examine their versatility under different conditions, ranging from ice-cold water to hot water. The green chemical herder retracted oil slicks by up to ~500, 700, and 2500% at 5°, 20°, and 35°C, respectively, during the first 10 min of the experiment, which is on a par with the current best chemical herders in practice.

scholarly journals Changes in the composition of marine and sea-ice diatoms derived from sedimentary ancient DNA of the eastern Fram Strait over the past 30 000 years

Ocean Science ◽  
2020 ◽  
Vol 16 (5) ◽  
pp. 1017-1032
Author(s):  
Heike H. Zimmermann ◽  
Kathleen R. Stoof-Leichsenring ◽  
Stefan Kruse ◽  
Juliane Müller ◽  
Ruediger Stein ◽  
...  
Keyword(s):  
Sea Ice ◽  
Ancient Dna ◽  
Cold Water ◽  
Taxonomic Composition ◽  
Fram Strait ◽  
Pcr Products ◽  
Ideal Study ◽  
Late Weichselian ◽  
The Last Glacial Maximum ◽  
The Last Glacial

Abstract. The Fram Strait is an area with a relatively low and irregular distribution of diatom microfossils in surface sediments, and thus microfossil records are scarce, rarely exceed the Holocene, and contain sparse information about past richness and taxonomic composition. These attributes make the Fram Strait an ideal study site to test the utility of sedimentary ancient DNA (sedaDNA) metabarcoding. Amplifying a short, partial rbcL marker from samples of sediment core MSM05/5-712-2 resulted in 95.7 % of our sequences being assigned to diatoms across 18 different families, with 38.6 % of them being resolved to species and 25.8 % to genus level. Independent replicates show a high similarity of PCR products, especially in the oldest samples. Diatom sedaDNA richness is highest in the Late Weichselian and lowest in Mid- and Late Holocene samples. Taxonomic composition is dominated by cold-water and sea-ice-associated diatoms and suggests several reorganisations – after the Last Glacial Maximum, after the Younger Dryas, and after the Early and after the Mid-Holocene. Different sequences assigned to, amongst others, Chaetoceros socialis indicate the detectability of intra-specific diversity using sedaDNA. We detect no clear pattern between our diatom sedaDNA record and the previously published IP25 record of this core, although proportions of pennate diatoms increase with higher IP25 concentrations and proportions of Nitzschia cf. frigida exceeding 2 % of the assemblage point towards past sea-ice presence.

ZOOBENTHOS OF WATERCOURSES IN THE BUKHTARMA RIVER BASIN (UPPER IRTYSH, SOUTH-WESTERN ALTAI) AT REFERENCE SITES AND IN THE IMPACT ZONE

2021 ◽  
pp. 66-83
Author(s):  
A. Evseeva
Keyword(s):  
River Basin ◽  
Cold Water ◽  
Taxonomic Composition ◽  
Anthropogenic Factors ◽  
Impact Zone ◽  
High Oxygen Content ◽  
Water Courses ◽  
Cold Water Temperature ◽  
Composition Structure ◽  
The Impact

The composition, structure, and spatial distribution of zoobenthos in streams of the Bukhtarma River basin are described and quantitative indicators of benthos in the lower course of the Bukhtarma River are given. The predominance of insects from the orders of mayflies, caddisflies, and freckles is characteristic of the water-courses in the Bukhtarma River basin and is associated with the presence of stony soils in the rivers, rapid flow, moderate-cold-water temperature regime, and high oxygen content in the water – factors that are most favorable for these groups of invertebrates. To assess the ecological state of surface waters in the streams under study by bioindication methods, TBI, BMWP, ASPT, and ERT biotic indices are used. The taxonomic composition of each of the studied watercourses and river sections is formed in accordance with specific environmental conditions associated with natural and anthropogenic factors. It is established that watercourses in the reference areas can be used as reference ones in accordance with the requirements of the EU Framework Water Directive, and the characteristics of invariant States of biocenoses of the lower course of the Bukhtarma River in the impact zone are also given using the criteria of the V. A. Abakumov system of ecological modulations.

scholarly journals New particle formation events observed at the King Sejong Station, Antarctic Peninsula – Part 2: Link with the oceanic biological activities

2019 ◽  
Vol 19 (11) ◽  
pp. 7595-7608 ◽  
Author(s):  
Eunho Jang ◽  
Ki-Tae Park ◽  
Young Jun Yoon ◽  
Tae-Wook Kim ◽  
Sang-Bum Hong ◽  
...  
Keyword(s):  
Austral Summer ◽  
Particle Formation ◽  
Taxonomic Composition ◽  
Weddell Sea ◽  
Marine Biota ◽  
New Particle Formation ◽  
Air Masses ◽  
Bellingshausen Sea ◽  
The Antarctic ◽  
New Particles

Abstract. Marine biota is an important source of atmospheric aerosol particles in the remote marine atmosphere. However, the relationship between new particle formation and marine biota is poorly quantified. Long-term observations (from 2009 to 2016) of the physical properties of atmospheric aerosol particles measured at the Antarctic Peninsula (King Sejong Station; 62.2∘ S, 58.8∘ W) and satellite-derived estimates of the biological characteristics were analyzed to identify the link between new particle formation and marine biota. New particle formation events in the Antarctic atmosphere showed distinct seasonal variations, with the highest values occurring when the air mass originated from the ocean domain during the productive austral summer (December, January and February). Interestingly, new particle formation events were more frequent in the air masses that originated from the Bellingshausen Sea than in those that originated from the Weddell Sea. The monthly mean number concentration of nanoparticles (2.5–10 nm in diameter) was >2-fold higher when the air masses passed over the Bellingshausen Sea than the Weddell Sea, whereas the biomass of phytoplankton in the Weddell Sea was more than ∼70 % higher than that of the Bellingshausen Sea during the austral summer period. Dimethyl sulfide (DMS) is of marine origin and its oxidative products are known to be one of the major components in the formation of new particles. Both satellite-derived estimates of the biological characteristics (dimethylsulfoniopropionate, DMSP; precursor of DMS) and phytoplankton taxonomic composition and in situ methanesulfonic acid (84 daily measurements during the summer period in 2013 and 2014) analysis revealed that DMS(P)-rich phytoplankton were more dominant in the Bellingshausen Sea than in the Weddell Sea. Furthermore, the number concentration of nanoparticles was positively correlated with the biomass of phytoplankton during the period when DMS(P)-rich phytoplankton predominate. These results indicate that oceanic DMS emissions could play a key role in the formation of new particles; moreover, the taxonomic composition of phytoplankton could affect the formation of new particles in the Antarctic Ocean.

scholarly journals DISTRIBUCIÓN Y DENSIDAD DE ICTIOPLANCTON EN EL ESTUARIO DE BAHÍA MÁLAGA, PACÍFICO COLOMBIANO (SEPTIEMBRE DE 2009-FEBRERO DE 2010)

2016 ◽  
Vol 43 (1) ◽  
Author(s):  
Diana Medina Contreras ◽  
Jaime Cantera ◽  
Eugenia Escarria ◽  
Luz M Mejía Ladino
Keyword(s):  
Fish Assemblages ◽  
Larval Fish ◽  
Fish Larvae ◽  
Larval Density ◽  
Temporal Distribution ◽  
Mesh Size ◽  
Temporal Variations ◽  
Taxonomic Composition ◽  
Total Density ◽  
The Relationship

The density, taxonomic composition, and spatial and temporal distribution of the estuarine ichthyoplankton of Bahía Málaga (Pacific coast of Colombia) are described, as well as the relationship between biological parameters and some physicochemical variables. Samples were collected at 12 stations along the principal navigation canal; these samples were taken in four areas following the design of Barletta-Bergan. Surface sweeps were carried out with a conical-cylindrical net (mesh size 500 µm, mouth diameter 0.6 m, length 3.5 m). Salinity and temperature were measured before each sweep. A total of 69019 larvae/1000 m³, representing 23 families, 36 genera and 40 species were collected during monthly sampling from September, 2009 to February, 2010. Carangidae (39.0%) was the most abundant family, followed by Sciaenidae (27.1%) and Engraulidae (20.1%). The most frequent families were Sciaenidae (26.6%), followed by Carangidae (22.8%) and Engraulidae (14.7%) which are important families in larval fish assemblages in tropical estuaries. Eighty percent of total density was provided by six species, of which Seriola morphotype 1 (Carangidae) and Cetengraulis mysticetus (Engraulidae) were the most abundant and dominant. No correlation was found between density and salinity (Spearman, R = 0.23) or temperature (Spearman, R = 0.51). Analysis of spatial and temporal variations of larval density shows significant differences among the months sampled (Anova, p = 0.0029; p < 0.05), but not among areas (Anova, p = 0.078), suggesting that Bahía Málaga offers adequate conditions for the presence of fish larvae.

scholarly journals New particle formation events observed at the King Sejong Station, Antarctic Peninsula – Part 2: Link with the oceanic biological activities

2018 ◽  
Author(s):  
Eunho Jang ◽  
Ki-Tae Park ◽  
Young Jun Yoon ◽  
Tae-Wook Kim ◽  
Sang-Bum Hong ◽  
...  
Keyword(s):  
Austral Summer ◽  
Particle Formation ◽  
Taxonomic Composition ◽  
Number Concentration ◽  
Weddell Sea ◽  
Marine Biota ◽  
New Particle Formation ◽  
Air Masses ◽  
Bellingshausen Sea ◽  
The Antarctic

Abstract. Marine biota is an important source of atmospheric aerosols in the remote marine atmosphere. Long-term observations (from 2009 to 2016) of the physical properties of atmospheric aerosol particles measured at the Antarctic Peninsula (King Sejong Station; 62.2° S, 58.8° W) and satellite-derived estimates of the biological characteristics were analyzed to identify the link between new particle formation and marine biota. New particle formation events in the Antarctic atmosphere showed distinct seasonal variations, with the highest values occurring during austral summer (December, January and February). Interestingly, new particle formation events were more frequent in the air masses that originated from the Bellingshausen Sea than in those that originated from the Weddell Sea. The monthly mean number concentration of nanoparticles (2.5–10 nm in diameter) was > 2-fold when the air masses passed over the Bellingshausen Sea than the Weddell Sea, whereas the biomass of phytoplankton in the Weddell Sea was more than ~ 70 % higher than that of the Bellingshausen Sea during the austral summer period. Dimethyl sulfide (DMS) is of marine origin and its oxidative products are known to be one of the major components in the formation of new particles. Both satellite-derived estimates of the biological characteristics (dimethylsulfoniopropionate (DMSP; precursor of DMS) and phytoplankton taxonomic composition) and in situ methanesulfonic acid (MSA; oxidation product of DMS) analysis revealed that DMS(P)-rich phytoplankton were more dominant in the Bellingshausen Sea than in the Weddell Sea. Furthermore, the number concentration of nanoparticles was positively correlated with the biomass of phytoplankton during the period when DMS(P)-rich phytoplankton predominate. These results indicate that oceanic DMS emissions could play a key role in the formation of new particles; moreover, the taxonomic composition of phytoplankton could affect the formation of secondary organic aerosols in the Antarctic Ocean.

scholarly journals High tolerance of microzooplankton to ocean acidification in an Arctic coastal plankton community

2013 ◽  
Vol 10 (3) ◽  
pp. 1471-1481 ◽  
Author(s):  
N. Aberle ◽  
K. G. Schulz ◽  
A. Stuhr ◽  
A. M. Malzahn ◽  
A. Ludwig ◽  
...  
Keyword(s):  
Ocean Acidification ◽  
Indirect Effects ◽  
High Arctic ◽  
Taxonomic Composition ◽  
High Pco2 ◽  
Marine Biota ◽  
High Tolerance ◽  
Wide Range ◽  
Low Sensitivity ◽  
The Impact

Abstract. Impacts of ocean acidification (OA) on marine biota have been observed in a wide range of marine systems. We used a mesocosm approach to study the response of a high Arctic coastal microzooplankton community during the post-bloom period in Kongsfjorden (Svalbard) to direct and indirect effects of high pCO2/low pH. We found almost no direct effects of OA on microzooplankton composition and diversity. Both the relative shares of ciliates and heterotrophic dinoflagellates as well as the taxonomic composition of microzooplankton remained unaffected by changes in pCO2/pH. Although the different pCO2 treatments affected food availability and phytoplankton composition, no indirect effects (e.g. on the total carrying capacity and phenology of microzooplankton) could be observed. Our data point to a high tolerance of this Arctic microzooplankton community to changes in pCO2/pH. Future studies on the impact of OA on plankton communities should include microzooplankton in order to test whether the observed low sensitivity to OA is typical for coastal communities where changes in seawater pH occur frequently.

Mesh size effects on mesozooplankton community structure in a semi-enclosed coastal area and surrounding sea (South Adriatic Sea)

2014 ◽  
Vol 35 (4) ◽  
pp. 445-455 ◽  
Author(s):  
Marijana Miloslavić ◽  
Davor Lučić ◽  
Barbara Gangai ◽  
Ivona Onofri
Keyword(s):  
Community Structure ◽  
Coastal Area ◽  
Size Effects ◽  
Adriatic Sea ◽  
Mesh Size ◽  
Mesozooplankton Community

scholarly journals Zooplankton distribution in Mesophotic Corals at Bajo Frijol seamount, Colombian Caribbean

2021 ◽  
Vol 26 (3) ◽  
pp. 281-300
Author(s):  
Laura Contreras Vega ◽  
Alejandro Henao Castr ◽  
Gabriel R Navas S
Keyword(s):  
Water Column ◽  
Relative Abundance ◽  
Food Resource ◽  
Zooplankton Community ◽  
Mesh Size ◽  
Taxonomic Composition ◽  
Mesophotic Coral Ecosystems ◽  
Natural Park ◽  
Three Samples ◽  
Large Groups

Mesophotic coral ecosystems shelter unique communities, but have not been studied enough due to the high cost for the available technologies. The zooplankton have become the primary food resource of the polyps at these environments, due to the low photosynthesis rate of its zooxanthellae, . Therefore, the purpose of this work was to study the zooplankton community associated to the MCEs in Bajo Frijol, in the Corales de Profundidad National Natural Park, and compare its composition with the zooplankton community from shallower parts of the water column. Three samples were taken, filtering 24 L of seawater (45 µm mesh size) at each station with a device designed to collect zooplankton right on top of the reef substrate. The taxonomic composition, density and relative abundance were obtained. A resemblance analysis was performed, complemented with a cluster, an MDS and a modified Kandoorp test. The analysis showed clear differences between the water column samples from those taken close to the reef. It also showed the separation of the community at the seamount into two large groups: north and center-south, both with exclusive species.

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