scholarly journals The AMERIGO Lander and the Automatic Benthic Chamber (CBA): Two New Instruments to Measure Benthic Fluxes of Dissolved Chemical Species

Sensors ◽  
2019 ◽  
Vol 19 (11) ◽  
pp. 2632 ◽  
Author(s):  
Federico Spagnoli ◽  
Pierluigi Penna ◽  
Giordano Giuliani ◽  
Luca Masini ◽  
Valter Martinotti
Keyword(s):  
Chemical Species ◽  
Biogeochemical Cycle ◽  
Benthic Chamber ◽  
Environmental Impact Assessments ◽  
Deep Waters ◽  
Benthic Pelagic Coupling ◽  
Benthic Ecosystems ◽  
Atmospheric Inputs ◽  
Ecological Pressure ◽  
Coupling Processes

Marine environments are currently subject to strong ecological pressure due to local and global anthropic stressors, such as pollutants and atmospheric inputs, which also cause ocean acidification and warming. These strains can result in biogeochemical cycle variations, environmental pollution, and changes in benthic-pelagic coupling processes. Two new devices, the Amerigo Lander and the Automatic Benthic Chamber (CBA), have been developed to measure the fluxes of dissolved chemical species between sediment and the water column, to assess the biogeochemical cycle and benthic-pelagic coupling alterations due to human activities. The Amerigo Lander can operate in shallow as well as deep water (up to 6000 m), whereas the CBA has been developed for the continental shelf (up to 200 m). The lander can also be used to deploy a range of instruments on the seafloor, to study the benthic ecosystems. The two devices have successfully been tested in a variety of research tasks and environmental impact assessments in shallow and deep waters. Their measured flux data show good agreement and are also consistent with previous data.

Predation behaviour of millimetre-sized hydrozoan polyps on early ivory shell juveniles

2020 ◽  
Vol 100 (6) ◽  
pp. 889-895
Author(s):  
Yulin Huang ◽  
Jingqiang Fu ◽  
Yutong Shi ◽  
Yunan Wang ◽  
Qi Cui ◽  
...  
Keyword(s):  
Large Scale ◽  
Management Practices ◽  
Molecular Data ◽  
Babylonia Areolata ◽  
Polyp Stage ◽  
Benthic Pelagic Coupling ◽  
Morphological And Molecular Data ◽  
Almost All ◽  
Coupling Processes ◽  
Colonial Hydroid

AbstractMarine hydroids, the polyp stage of hydrozoans, are assumed to be carnivores and play an important role in benthic-pelagic coupling processes by regulating zooplankton populations and transferring energy. The known hydroid diets mainly consist of zooplankton as well as some benthic diatoms and metazoans, almost all of which have smaller dimensions than the polyp. In the present study, a large-scale breeding failure of the early juveniles of the ivory shell Babylonia areolata (Mollusca: Gastropoda: Babyloniidae) was found in a local aquaculture farm in Fujian, China in July 2018. About 640,000 out of 800,000 early juveniles (80%) died due to predation by a millimetre-sized colonial hydroid species that was initially overlooked. The hydrozoan species was identified as Eirene sp. (Cnidaria: Hydrozoa: Eirenidae) via the integration of morphological and molecular data. A laboratory feeding experiment showed that the hydroid predation led to an overall mortality of ivory shell juveniles of up to 92.6% after 48 h. The predation process was observed in the laboratory and a video showing the entire process was prepared. This is the first report of hydroids preying on gastropod juveniles, revealing a previously unknown threat to mollusc aquaculture including ivory shells. Several management practices are suggested to mitigate this newly recognized threat.

scholarly journals The Effects of the Nonnative Brittle Star Ophiothela Mirabilis Verrill, 1867 on the Feeding Performance of an Octocoral Host in a Southwestern Atlantic Rocky Shore

2021 ◽  
Author(s):  
Patrick Derviche ◽  
Paulo da Cunha Lana
Keyword(s):  
Rocky Shore ◽  
Experimental Studies ◽  
Brittle Star ◽  
Host Feeding ◽  
Western Atlantic ◽  
Feeding Performance ◽  
Functional Features ◽  
Benthic Pelagic Coupling ◽  
The Impact ◽  
Coupling Processes

Abstract The Pacific epizoic brittle star Ophiothela mirabilis Verrill, 1867 has widely spread and colonized hosts at high densities along the Western Atlantic. We assessed the impacts of O. mirabilis on the feeding performance of the preferred host Leptogorgia punicea (Milne Edwards & Haime, 1857) through in situ experiments using incubation chambers and estimated its putative effects on the benthic-pelagic coupling processes of a rocky shore system. The feeding rates and heterotrophic carbon inputs of L. punicea treatments with high colonization by O. mirabilis (5.4 ± 0.6 individuals cm− 2 of host area) were compared to host controls naturally without brittle stars. No significant differences in host feeding performance were observed between the control and treatments. Overall, L. punicea ingested 2,688,569 ± 1,627,948 particles g DW (dry weight)−1 hour− 1 (mean ± standard deviation), corresponding to 156.8 ± 207.5 µg of carbon (C) g DW− 1 hour− 1. Therefore, although octocorals hosting O. mirabilis may have impaired polyp opening and extension, their feeding performance remains similar. In this sense, the impact of O. mirabilis on the carbon flux of the rocky shore system driven by octocoral ingestion is minimal. The grazing rate of 67.4 ± 89.2 mg C m− 2 day− 1 highlights the significant role of L. punicea in such benthic-pelagic coupling processes. Notwithstanding, further laboratory and field experimental studies assessing the effects on host taxa with distinct morphological and functional features are needed to better understand the responses of the recipient hard-bottom systems along the Western Atlantic to increasing densities of O. mirabilis.

scholarly journals The Importance of Food Pulses in Benthic-Pelagic Coupling Processes of Passive Suspension Feeders

Water ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 997
Author(s):  
Sergio Rossi ◽  
Lucia Rizzo
Keyword(s):  
Water Column ◽  
Single Species ◽  
Branching Pattern ◽  
Suspension Feeders ◽  
Paramuricea Clavata ◽  
Order Of Magnitude ◽  
Benthic Pelagic Coupling ◽  
Intensive Sampling ◽  
Coupling Processes ◽  
Capture Rates

Benthic-pelagic coupling processes and the quantity of carbon transferred from the water column to the benthic suspension feeders needs multiple intensive sampling approaches where several environmental variables and benthos performance are quantified. Here, activity, dietary composition, and capture rates of three Mediterranean gorgonians (Paramuricea clavata, Eunicella singularis, and Leptogorgia sarmentosa) were assessed in an intensive cycle considering different variables such as the seston concentration and quality (e.g., carbon, nitrogen, and zooplankton), the colony branch patterns, and the energetic input of the single species (i.e., mixotrophic and heterotrophic). The three species showed clear differences in their impact on the seston concentration. Paramuricea clavata, the most densely distributed, showed a greater impact on the near bottom water column seston. The lowest impact of E. singularis on the seston could be explained by its mixotrophy and colony branching pattern. Leptogorgia sarmentosa had a similar impact as E. singularis, having a much more complex branching pattern and more than an order of magnitude smaller number of colonies per meter square than the other two octocorals. The amount of carbon ingested in the peaks of the capture rates in the three species may cover a non-neglectable proportion of the potential carbon fluxes.

The role of Mediterranean sponges in benthic–pelagic coupling processes: Aplysina aerophoba and Axinella polypoides case studies

2016 ◽  
Vol 477 ◽  
pp. 57-68 ◽  
Author(s):  
Martina Coppari ◽  
Andrea Gori ◽  
Núria Viladrich ◽  
Luca Saponari ◽  
Antonio Canepa ◽  
...  
Keyword(s):  
Case Studies ◽  
Benthic Pelagic Coupling ◽  
Aplysina Aerophoba ◽  
Coupling Processes

scholarly journals The importance of coastal gorgonians in the blue carbon budget

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Martina Coppari ◽  
Chiara Zanella ◽  
Sergio Rossi
Keyword(s):  
Size Structure ◽  
Mediterranean Area ◽  
C Sequestration ◽  
Marine Animal ◽  
Starting Point ◽  
Paramuricea Clavata ◽  
Nw Mediterranean ◽  
Gorgonian Species ◽  
Benthic Pelagic Coupling ◽  
Coupling Processes

Abstract Terrestrial (trees, shrubs) and marine (seaweeds and seagrasses) organisms act as carbon (C) sinks, but the role of benthic suspension feeders in this regard has been largely neglected so far. Gorgonians are one of the most conspicuous inhabitants of marine animal forests (mainly composed of sessile filter feeders); their seston capture rates influence benthic-pelagic coupling processes and they act as C sinks immobilizing carbon in their long-living structures. Three gorgonian species (Paramuricea clavata, Eunicella singularis and Leptogorgia sarmentosa) were studied coupling data of population size structure, biomass and spatial distribution in a NW Mediterranean area (Cap de Creus, Spain) with feeding, respiration and growth rates. In the study area, we calculated that P. clavata sequestered 0.73 ± 0.71 g C m−2 year−1, E. singularis 0.73 ± 0.89 g C m−2 year−1 and L. sarmentosa 0.03 ± 0.02 g C m−2 year−1. To our knowledge, this is the first attempt to calculate the importance as C sinks of gorgonian species that we consider as a starting point to estimate the importance of marine animal forests in C sequestration, and to ensure appropriate management and protection especially in areas and at depths where they are concentrated.

scholarly journals Gut Microbial Composition and Diversity in Four Ophiuroid Species: Divergence Between Suspension Feeder and Scavenger and Their Symbiotic Microbes

2021 ◽  
Vol 12 ◽  
Author(s):  
Yue Dong ◽  
Yixuan Li ◽  
Peiqing He ◽  
Zongling Wang ◽  
Shiliang Fan ◽  
...  
Keyword(s):  
Gut Microbiota ◽  
Yellow Sea ◽  
Function Analysis ◽  
The Yellow Sea ◽  
Microbial Composition ◽  
Significant Divergence ◽  
Benthic Pelagic Coupling ◽  
Benthic Ecosystems ◽  
And Function ◽  
Dominant Bacteria

Gut microbiota have important roles in the survival and adaptation of the host. Ophiuroids, as the worldwide dominant benthos, have ecological roles in benthic–pelagic coupling in the sea floor. However, little is known about the composition and diversity of their gut microbiota and its potential functions in benthic ecosystems. In present study, we preformed 16S rRNA sequencing and function analysis in four dominant species (Stegophiura sladeni, Ophiopholis mirabilis, Ophiura sarsii vadicola, and Ophiura kinbergi) with two feeding types (suspension feeding/herbivores and scavenger/carnivores) from the Yellow Sea, China. Results showed that 56 phyla and 569 genera of microbiota were identified among ophiuroid guts. Multivariate and diversity analyses showed that the ophiuroid gut microbiota were independent and have higher biodiversity to the sediment microbial in the Yellow Sea. Phyla Proteobacteria, Firmicutes, Tenericutes, and Bacteroidetes were the dominant bacteria, with more than 80% abundance among the four ophiuroid species. A comparison among the gut microbial compositions among four ophiuroids showed the similarity of two offshore carnivore ophiuroids (S. sladeni and O. sarsii vadicola) and variation in the dominant microbiota types of three nearshore ophiuroids (S. sladeni, O. mirabilis, and O. kinbergi). The functional analysis revealed the significant differences of the environment-related expression in S. sladeni gut microbiota between nearshore and offshore environments. The Phylogenetic Investigation of Communities by Reconstruction of Unobserved States (PICRUSt) functional annotation showed the significant divergence of metabolism pathways between two nearshore species, the herbivores O. mirabilis and carnivores S. sladeni, such as the Lipid metabolism, Carbohydrate metabolism, and Metabolism of cofactors and vitamins. The homolog search and phylogenetic analysis identified the first gut symbiotic Candidatus Hepatoplasma in S. sladeni with important roles for the nutrient metabolisms. Overall, our study reported the comprehensive data of ophiuroid gut microbiota, while the functional microbiome provides insight into the physiology and environmental adaptation in ophiuroids.

scholarly journals New insights on the role of organic speciation in the biogeochemical cycle of dissolved cobalt in the southeastern Atlantic and the Southern Ocean

2012 ◽  
Vol 9 (3) ◽  
pp. 3381-3422 ◽  
Author(s):  
J. Bown ◽  
M. Boye ◽  
D. M. Nelson
Keyword(s):  
Southern Ocean ◽  
Surface Waters ◽  
Organic Ligands ◽  
Biogeochemical Cycle ◽  
Combined Effects ◽  
Deep Waters ◽  
Organic Complexes ◽  
Organic Speciation ◽  
The Antarctic ◽  
Southeastern Atlantic

Abstract. The organic speciation of dissolved cobalt was investigated in the subtropical region of the southeastern Atlantic, and in the Antarctic Circumpolar Current (ACC) and the northern Weddell Gyre in the Southern Ocean between 33°58′S and 57°33′S along the Greenwich Meridian during the austral summer of 2008. The organic speciation of cobalt was determined by Competing Ligand Exchange Adsorptive Cathodic Stripping Voltammetry (CLE-AdCSV) using nioxime as a competing ligand. The conditional stability constants (log K'CoL) of the organic complexes of Co ranged between 17.9 and 20.1, and the concentrations of the organic ligands (L) between 26 and 73 pM. Most dissolved cobalt (DCo) was organically complexed in the water-column (60 to ≥99.9 %). There were clear vertical and meridional patterns in the distribution of L and the organic speciation of DCo along the section. These patterns suggested a biological source of the organic ligands in the surface waters of the subtropical domain and northern subantarctic region, potentially driven by the cyanobacteria, and a removal of the organic Co by direct or indirect biological uptake. The highest L:DCo ratio (e.g. 5.81 ± 1.07 pM pM–1) observed in these surface waters reflected the combined effects of ligand production and consumption of DCo. As a result of these combined effects, the calculated concentrations of free, unbound Co ([Co′]) in subtropical and subantarctic surface waters were very low, generally between 10–19 and 10–17 M. In intermediate and deep waters, the South African margins can be a source of organic ligands, as it was suggested to be for DCo (Bown et al., 2011), although a significant portion of DCo (up to 15 %) can be stabilized and transported as inorganic species in those DCo-enriched water-masses. Contrastingly, the distribution of L did not suggest an intense biological production of L around the Antarctic Polar Front where a diatom bloom had recently occurred. Here [Co′] can be several orders of magnitude higher than those reported in the subtropical domain, suggesting that cobalt limitation was unlikely in the ACC domain. The almost invariant L:DCo ratio of ~1 recorded in these surface waters also reflected the conservative behaviours of both the organic ligands and DCo. In deeper waters relatively higher ligand concentrations were observed in waters previously identified as DCo sources (Bown et al., 2011). At those depths the eastward increase of DCo could be associated with a large scale transport and remineralisation of DCo as organic complexes; here, the fraction stabilized as inorganic Co was much lower but still significant (up to 25 %) in the low oxygenated Upper Circumpolar Deep Waters. The organic speciation may thus be a central factor in the biogeochemical cycle of DCo in those areas, playing a major role in the bioavailability and the geochemistry of Co.

scholarly journals Sponge biodiversity

2007 ◽  
Vol 87 (6) ◽  
pp. 1345-1348 ◽  
Author(s):  
R.W.M. van Soest
Keyword(s):  
Microbial Biomass ◽  
Benthic Communities ◽  
High Impact ◽  
Modern Times ◽  
Benthic Pelagic Coupling ◽  
Coupling Processes

Sponges are an integral part of marine benthic communities with a high-impact role in benthic–pelagic coupling processes, as an important source of food for demersal grazers and predators, as hosts of a highly diverse microbial biomass, and as bio-eroders. Sponges provide age-old (hygienic) services to humans and continue to be of interest in modern times as sources of an unprecedented array of useful substances.

Chemical Species Identification in an SEM by Changes in Emitted X-Ray Energies

1974 ◽  
Vol 32 ◽  
pp. 570-571
Author(s):  
R. H. Duff
Keyword(s):  
Species Identification ◽  
Valence Electron ◽  
Chemical Species ◽  
X Rays ◽  
Chemical Bonds ◽  
Small Shift ◽  
X Ray ◽  
Electron Transitions ◽  
Peak Energy ◽  
Chemical Combination

A material irradiated with electrons emits x-rays having energies characteristic of the elements present. Chemical combination between elements results in a small shift of the peak energies of these characteristic x-rays because chemical bonds between different elements have different energies. The energy differences of the characteristic x-rays resulting from valence electron transitions can be used to identify the chemical species present and to obtain information about the chemical bond itself. Although these peak-energy shifts have been well known for a number of years, their use for chemical-species identification in small volumes of material was not realized until the development of the electron microprobe.

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