scholarly journals Metatranscriptomic Analyses of Plankton Communities Inhabiting Surface and Subpycnocline Waters of the Chesapeake Bay during Oxic-Anoxic-Oxic Transitions

2013 ◽  
Vol 80 (1) ◽  
pp. 328-338 ◽  
Author(s):  
Ian Hewson ◽  
Erin M. Eggleston ◽  
Mary Doherty ◽  
Dong Yoon Lee ◽  
Michael Owens ◽  
...  
Keyword(s):  
Chesapeake Bay ◽  
Algal Blooms ◽  
Late Summer ◽  
Shallow Waters ◽  
Redox States ◽  
Anoxic Waters ◽  
Deep Waters ◽  
Cytochrome Oxidases ◽  
Microbial Plankton ◽  
Plankton Communities

ABSTRACTWe used metatranscriptomics to study the gene transcription patterns of microbial plankton (0.2 to 64 μm) at a mesohaline station in the Chesapeake Bay under transitions from oxic to anoxic waters in spring and from anoxic to oxic waters in autumn. Samples were collected from surface (i.e., above pycnocline) waters (3 m) and from waters beneath the pycnocline (16 to 22 m) in both 2010 and 2011. Metatranscriptome profiles based on function and potential phylogeny were different between 2010 and 2011 and strongly variable in 2011. This difference in variability corresponded with a highly variable ratio of eukaryotic to bacterial sequences (0.3 to 5.5), reflecting transient algal blooms in 2011 that were absent in 2010. The similarity between metatranscriptomes changed at a lower rate during the transition from oxic to anoxic waters than after the return to oxic conditions. Transcripts related to photosynthesis and low-affinity cytochrome oxidases were significantly higher in shallow than in deep waters, while in deep water genes involved in anaerobic metabolism, particularly sulfate reduction, succinyl coenzyme A (succinyl-CoA)-to-propionyl-CoA conversion, and menaquinone synthesis, were enriched relative to in shallow waters. Expected transitions in metabolism between oxic and anoxic deep waters were reflected in elevated levels of anaerobic respiratory reductases and utilization of propenediol and acetoin. The percentage of archaeal transcripts increased in both years in late summer (from 0.1 to 4.4% of all transcripts in 2010 and from 0.1 to 6.2% in 2011). Denitrification-related genes were expressed in a predicted pattern during the oxic-anoxic transition. Overall, our data suggest that Chesapeake Bay microbial assemblages express gene suites differently in shallow and deep waters and that differences in deep waters reflect variable redox states.

Influx of streaming methane into anoxic waters of the Black Sea basin

2019 ◽  
Vol 59 (6) ◽  
pp. 952-963
Author(s):  
Yu. G. Artemov ◽  
V. N. Egorov ◽  
S. B. Gulin
Keyword(s):  
Spatial Distribution ◽  
Black Sea ◽  
The Black Sea ◽  
Gas Bubble ◽  
Dissolved Methane ◽  
Anoxic Waters ◽  
Deep Waters ◽  
Methane Budget

Based on data on the spatial distribution and fluxes of streaming (bubbling) methane within the Black Sea, the rate of dissolved methane inflow to Black Sea deep waters was assessed. Calculations showed that gas bubble streams annually replenish the methane budget in the Black Sea by 1.2 109 m3, or 0.9 Tg, which is considerably less than determined by known biogeochemical estimates of components of methane balance in the Black Sea.

scholarly journals Three new species of Scissurellidae (Gastropoda, Prosobranchia) from the coast of Brazil

1972 ◽  
Vol 21 (0) ◽  
pp. 01-13 ◽  
Author(s):  
Pierre Ch. Montouchet
Keyword(s):  
New Species ◽  
Sao Paulo ◽  
The State ◽  
Shallow Waters ◽  
Brazilian Coast ◽  
São Paulo ◽  
Internal Anatomy ◽  
The Third ◽  
Deep Waters ◽  
Three New Species

A consultation of the original descriptions of the genera of Scissurellidae led the author to conclude that the valid names for the genera of this family are: Scissurella d'Orbigny, 1823 (redescription by Sowerby, 1824), Anatoma Woodward, 1859, Inoisura Hedley, 1904, Scissurona Iredale, 1924, Sinezona Finlay, 1927. Scissurella and Anatoma are cosmopolites, the first generally living in shallow waters, associated to sea-weeds, while the second is found in deep waters. The three last genera are restricted to Australasia. Three new species are described from the Brazilian coast: Soissu rella alexandrei, Scissurella eleotilis and Scissurella morretesi. The internal anatomy of S. alexandrei is described. These three new species have been found in littoral shallow waters, the two first on the northeast Brazilian coast, the third on the coast of the State of São Paulo. The fourth known species of Scissurellidae from Brazil, Anatoma aedonia (Watson, 1886), was dredged by H.M.S, "Challenger", in 1873, off Pernambuco, 350 fm (640 m).

scholarly journals Earth observation for monitoring and mapping of cyanobacteria blooms. Case studies on five Italian lakes

2016 ◽  
Vol 76 (s1) ◽  
Author(s):  
Mariano Bresciani ◽  
Claudia Giardino ◽  
Rosaria Lauceri ◽  
Erica Matta ◽  
Ilaria Cazzaniga ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Algal Blooms ◽  
Remote Sensing Data ◽  
Late Summer ◽  
Eutrophic Lake ◽  
Cyanobacterial Blooms ◽  
Landsat 8 ◽  
Negative Effects ◽  
Eutrophic Lakes ◽  
Chl A

Cyanobacterial blooms occur in many parts of the world as a result of entirely natural causes or human activity. Due to their negative effects on water resources, efforts are made to monitor cyanobacteria dynamics. This study discusses the contribution of remote sensing methods for mapping cyanobacterial blooms in lakes in northern Italy. Semi-empirical approaches were used to flag scum and cyanobacteria and spectral inversion of bio-optical models was adopted to retrieve chlorophyll-a (Chl-a) concentrations. Landsat-8 OLI data provided us both the spatial distribution of Chl-a concentrations in a small eutrophic lake and the patchy distribution of scum in Lake Como. ENVISAT MERIS time series collected from 2003 to 2011 enabled the identification of dates when cyanobacterial blooms affected water quality in three small meso-eutrophic lakes in the same region. On average, algal blooms occurred in the three lakes for about 5 days a year, typically in late summer and early autumn. A suite of hyperspectral sensors on air- and space-borne platforms was used to map Chl-a concentrations in the productive waters of the Mantua lakes, finding values in the range of 20 to 100 mgm-3. The present findings were obtained by applying state of the art of methods applied to remote sensing data. Further research will focus on improving the accuracy of cyanobacteria mapping and adapting the algorithms to the new-generation of satellite sensors.

First record of Cladocroce (Porifera: Haplosclerida: Chalinidae) from the Eastern Pacific ocean with the description of Cladocroce reina sp. nov.

Zootaxa ◽  
2010 ◽  
Vol 2603 (1) ◽  
pp. 65
Author(s):  
JOSE MARIA AGUILAR-CAMACHO ◽  
JOSE LUIS CARBALLO
Keyword(s):  
Pacific Coast ◽  
Current Knowledge ◽  
First Record ◽  
Shallow Waters ◽  
Principal Characteristic ◽  
Mexican Pacific ◽  
Fiber Tracts ◽  
Deep Waters ◽  
The Family ◽  
A New Species

Chalinidae is a family of haplosclerid sponges with a delicate reticulated chaonosomal skeleton of uni-, pauci- or multispicular primary lines which are connected by unispicular secondary lines, and with an ectosomal skeleton, if present, formed by a regular hexagonal, unispicular, tangential reticulation (Weerdt 2002). Currently, the family harbors only five valid genera (Chalinula, Cladocroce, Dendrectilla, Dendroxea and Haliclona; Soest et al. 2008), although recent molecular studies suggest that a new rearrangement of the present classification is needed (Redmond et al. 2007). Cladocroce was described by Topsent (1892) from specimens collected in the Atlantic Ocean. The principal characteristic of this genus is the presence of multispicular fiber tracts with a rather dense subisotropic reticulation in between (Weerdt 2002). After that, 10 species have been described, most of them from deep waters and cold climates (Putchakarn et al. 2004). Only three species have been found living in shallow waters: C. aculeata Pulitzer-Finali, 1982 from the Great Barrier Reef, C. burapha Putchakarn et al., 2004 from the Gulf of Thailand, and C. tubulosa Pulitzer-Finali, 1993 from the port of Mombasa, in Kenya. Sponge taxonomy studies in the Mexican Pacific coast have been focused mainly on hadromerids, and particularly on boring sponges (Carballo et al. 2008), and the current knowledge of haplosclerids is very scarce (Cruz-Barraza & Carballo 2006). In this paper, a new species of Cladocroce is described and compared with the other species recorded worldwide. With this contribution the genus Cladocroce increases to 12 species.

scholarly journals The Algicidal Bacterium Kordia algicida Shapes a Natural Plankton Community

2019 ◽  
Vol 85 (7) ◽  
Author(s):  
Arite Bigalke ◽  
Nils Meyer ◽  
Lydia Alkistis Papanikolopoulou ◽  
Karen Helen Wiltshire ◽  
Georg Pohnert
Keyword(s):  
North Sea ◽  
Algal Blooms ◽  
Plankton Community ◽  
Algicidal Bacteria ◽  
Important Species ◽  
Substantial Impact ◽  
The North ◽  
Algicidal Bacterium ◽  
The North Sea ◽  
Plankton Communities

ABSTRACT Plankton communities consist of complex microbial consortia that change over time. These fluctuations can be only partially explained by limiting resources. Biotic factors such as herbivores and pathogens also contribute to the control of algal blooms. Here we address the effects of algicidal bacteria on a natural plankton community in an indoor enclosure experiment. The algicidal bacteria, introduced into plankton taken directly from the North Sea during a diatom bloom, caused the rapid decline of the bloom-forming Chaetoceros socialis within only 1 day. The haptophyte Phaeocystis, in contrast, is resistant to the lytic bacteria and could benefit from the removal of the competitor, as indicated by an onset of a bloom in the treated enclosures. This cascading effect caused by the bacterial pathogen accelerated the succession of Phaeocystis, which bloomed with a delay of only several weeks in the in situ waters at Helgoland Roads in the North Sea. The algicidal bacteria can thus modulate the community within the limits of the abiotic and biotic conditions of the local environment. Implications of our findings for plankton ecosystem functioning are discussed. IMPORTANCE Plankton communities change on a seasonal basis in temperate systems, with distinct succession patterns; this is mainly due to algal species that have their optimal timing relative to environmental conditions. We know that bacterial populations are also instrumental in the decay and termination of phytoplankton blooms. Here, we describe algicidal bacteria as modulators of this important species succession. Upon treatment of a natural plankton consortium with an algicidal bacterium, we observed a strong shift in the phytoplankton community structure, compared to controls, resulting in formation of a succeeding Phaeocystis bloom. Blooms of this alga have a substantial impact on global biogeochemical and ecological cycles, as they are responsible for a substantial proportion of primary production during spring in the North Sea. We propose that one of the key factors influencing such community shifts may be algicidal bacteria.

scholarly journals Current and Future Remote Sensing of Harmful Algal Blooms in the Chesapeake Bay to Support the Shellfish Industry

2020 ◽  
Vol 7 ◽  
Author(s):  
Jennifer L. Wolny ◽  
Michelle C. Tomlinson ◽  
Stephanie Schollaert Uz ◽  
Todd A. Egerton ◽  
John R. McKay ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Chesapeake Bay ◽  
Harmful Algal Blooms ◽  
Algal Blooms

Ecological Studies of Arctic Cod (Boreogadus saida) in Beaufort Sea Coastal Waters, Alaska

1982 ◽  
Vol 39 (3) ◽  
pp. 395-406 ◽  
Author(s):  
P. C. Craig ◽  
W. B. Griffiths ◽  
L. Haldorson ◽  
H. McElderry
Keyword(s):  
Life History ◽  
Coastal Waters ◽  
Life History Strategy ◽  
Late Summer ◽  
Beaufort Sea ◽  
Shallow Waters ◽  
Boreogadus Saida ◽  
Arctic Cod ◽  
Arctic Fish ◽  
Slow Growing

Fish use of Beaufort Sea coastal waters was examined during summer and winter periods 1977–80. Arctic cod (Boreogadus saida) were abundant but their occurrence was highly variable. They accounted for 8–78% of all fish caught in Simpson Lagoon during two summers, and 0.4–100% of catches at various coastal sites in winter. Arctic cod increased in abundance in the lagoon during late summer and some association was noted between their numbers and higher salinities but not temperature or turbidity. Some cod remained in shallow waters in early winter but deeper areas were used through the winter, and the highest catch rate was recorded 175 km offshore. Principal foods of the cod in nearshore waters were mysids (Mysis litoralis, M. relicta), amphipods (Onisimus glacialis), and copepods. The cod caught were generally small (60–170 mm) and young (ages 1–3). Most males matured at ages 2–3 and females at age 3. These size, age, and maturity characteristics indicate a life history strategy (r-selection) unlike that typified by many other arctic fish populations, particularly the freshwater and anadromous species which tend to be slow growing, late maturing and long-lived (K-selection).Key words: Arctic cod, Boreogadus saida; Beaufort Sea, distribution, life history strategy

Depth-dependent variation in condition and length-at-age of Atlantic cod (Gadus morhua) in the southern Gulf of St. Lawrence

2002 ◽  
Vol 59 (9) ◽  
pp. 1451-1459 ◽  
Author(s):  
G A Chouinard ◽  
D P Swain
Keyword(s):  
Deep Water ◽  
Gadus Morhua ◽  
Atlantic Cod ◽  
High Abundance ◽  
Shallow Waters ◽  
Depth Range ◽  
Deep Waters ◽  
Feeding Grounds

We describe depth-dependent variation in the condition and length-at-age of southern Gulf of St. Lawrence cod (Gadus morhua) on their feeding grounds in September 1971–2000. Bathymetric variation in condition appears to be linked to abundance. In periods of low abundance, condition was relatively uniform over shallow and intermediate depths (<100–125 m). During periods of high abundance, condition was highest in the shallowest waters and declined steadily as depth increased to 100 m. In all periods, condition was low in deep water. Bathymetric trends in length-at-age contrasted with those in condition. Length-at-age was high in the deep waters where condition was low. Length-at-age also tended to increase from minimum values at intermediate depths to high values in shallow waters. This tendency was most striking in the 1990s, a period when condition was uniform over this depth range. We discuss the ecological, bioenergetic, and sampling implications of these patterns.

scholarly journals Metabarcoding and metabolome analyses of copepod grazing reveal feeding preference and linkage to metabolite classes in dynamic microbial plankton communities

2016 ◽  
Vol 25 (21) ◽  
pp. 5585-5602 ◽  
Author(s):  
Jessica L. Ray ◽  
Julia Althammer ◽  
Katrine S. Skaar ◽  
Paolo Simonelli ◽  
Aud Larsen ◽  
...  
Keyword(s):  
Feeding Preference ◽  
Copepod Grazing ◽  
Microbial Plankton ◽  
Plankton Communities

Description of three species of Eurypon Gray, 1867 (Raspailiidae: Demospongiae: Porifera) from the Western Atlantic and a name to replace the the secondary homonym Eurypon topsenti

Zootaxa ◽  
2018 ◽  
Vol 4388 (1) ◽  
pp. 89
Author(s):  
THAYNÃ CAVALCANTI ◽  
GEORGE GARCIA SANTOS ◽  
ULISSES PINHEIRO
Keyword(s):  
New Species ◽  
Rio Grande ◽  
Valid Species ◽  
Shallow Waters ◽  
Bathymetric Range ◽  
Western Atlantic ◽  
Northeast Region ◽  
Deep Waters ◽  
Three New Species ◽  
First Time

Eurypon  Gray, 1867 comprises 49 valid species distributed worldwide, and in an extensive bathymetric range. Three Eurypon species are known for Brazil, all endemic from the Northeast region. Here, we describe three new species of Eurypon. Two of which are recorded from shallow waters (down to 100 m) off Pernambuco and Paraíba States, and one species is from deep waters (157 m) off Rio Grande do Norte State. Eurypon oxychaetum sp. nov. has large subtylostyles (1025–2125 µm, length), styles, two categories of acanthostyles and oxychaetes; Eurypon potiguaris sp. nov. has large tylostyles (1000–2315 µm, length), two categories of acanthostyles, and thin oxeas; Eurypon verticillatum sp. nov. is a blue sponge with exclusive verticillate acanthostyles. The new species were compared with all other Atlantic species of the genus. A replacement name for the secondary homonym Eurypon topsenti is proposed: Eurypon pulitzeri nom. nov. The presence of verticillate acanthostyles and oxychaetes spicules are reported for the first time in Table 1 genus. 

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