scholarly journals Multiple New Strains of Amphidomataceae (Dinophyceae) from the North Atlantic Revealed a High Toxin Profile Variability of Azadinium spinosum and a New Non-Toxigenic Az. cf. spinosum

2021 ◽  
Vol 9 (1) ◽  
pp. 134
Author(s):  
Urban Tillmann ◽  
Stephan Wietkamp ◽  
Haifeng Gu ◽  
Bernd Krock ◽  
Rafael Salas ◽  
...  
Keyword(s):  
North Sea ◽  
North Atlantic ◽  
Large Variability ◽  
The North ◽  
Cell Quota ◽  
The North Sea ◽  
Underlying Causes ◽  
Lipophilic Toxins ◽  
Species Specific ◽  
First Time

Azaspiracids (AZA) are a group of lipophilic toxins, which are produced by a few species of the marine nanoplanktonic dinoflagellates Azadinium and Amphidoma (Amphidomataceae). A survey was conducted in 2018 to increase knowledge on the diversity and distribution of amphidomatacean species and their toxins in Irish and North Sea waters (North Atlantic). We here present a detailed morphological, phylogenetic, and toxinological characterization of 82 new strains representing the potential AZA producers Azadinium spinosum and Amphidoma languida. A total of ten new strains of Am. languida were obtained from the North Sea, and all conformed in terms of morphology and toxin profile (AZA-38 and-39) with previous records from the area. Within 72 strains assigned to Az. spinosum there were strains of two distinct ribotypes (A and B) which consistently differed in their toxin profile (dominated by AZA-1 and -2 in ribotype A, and by AZA-11 and -51 in ribotype B strains). Five strains conformed in morphology with Az. spinosum, but no AZA could be detected in these strains. Moreover, they revealed significant nucleotide differences compared to known Az. spinosum sequences and clustered apart from all other Az. spinosum strains within the phylogenetic tree, and therefore were provisionally designated as Az. cf. spinosum. These Az. cf. spinosum strains without detectable AZA were shown not to cause amplification in the species-specific qPCR assay developed to detect and quantify Az. spinosum. As shown here for the first time, AZA profiles differed between strains of Az. spinosum ribotype A in the presence/absence of AZA-1, AZA-2, and/or AZA-33, with the majority of strains having all three AZA congeners, and others having only AZA-1, AZA-1 and AZA-2, or AZA-1 and AZA-33. In contrast, no AZA profile variability was observed in ribotype B strains. Multiple AZA analyses of a period of up to 18 months showed that toxin profiles (including absence of AZA for Az. cf. spinosum strains) were consistent and stable over time. Total AZA cell quotas were highly variable both among and within strains, with quotas ranging from 0.1 to 63 fg AZA cell−1. Cell quota variability of single AZA compounds for Az. spinosum strains could be as high as 330-fold, but the underlying causes for the extraordinary large variability of AZA cell quota is poorly understood.

Offshore Claims and Problems in the North Sea

1965 ◽  
Vol 59 (3) ◽  
pp. 505-522 ◽  
Author(s):  
Richard Young
Keyword(s):  
North Sea ◽  
Large Scale ◽  
Geneva Convention ◽  
Legal Principles ◽  
The North ◽  
Legal Problems ◽  
The North Sea ◽  
The Subject ◽  
First Time ◽  
Economic Considerations

The possible presence of very large petroleum and natural gas reserves in the area beneath the North Sea is currently the subject of intense investigation. If confirmed, as seems likely in at least some localities, this occurrence will raise legal problems of considerable interest and complexity. For the North Sea is not merely an oilfield covered by water: for centuries it has been one of the world's major fishery regions and the avenue to and from the world's busiest seaports. Thus all three of the present principal uses of the sea—fishing, navigation, and the exploitation of submarine resources—promise to meet for the first time on a large scale in an area where all are of major importance. The process of reconciling the various interests at stake will provide the first thoroughgoing test of the adequacy and acceptability of the general principles laid down in the 1958 Geneva Convention on the Continental Shelf and should add greatly to the practice and precedents available in this developing branch of the law. In the present article an attempt is made to review some of the geographical and economic considerations involved in the North Sea situation, to note some of the technical and legal developments that have already taken place, and to consider these elements in the light of the various interests and legal principles concerned.

Temperature, Salinity and Plankton in the Eastern North Atlantic and Coastal Waters of Britain, 1957.: I. The Characterisation and Distribution of Surface Waters

1963 ◽  
Vol 20 (3) ◽  
pp. 789-826 ◽  
Author(s):  
B. McK. Bary
Keyword(s):  
North Sea ◽  
North Atlantic ◽  
Coastal Waters ◽  
Water Bodies ◽  
English Channel ◽  
Oceanic Water ◽  
Climatic Fluctuations ◽  
The North ◽  
The North Sea ◽  
Eastern North Atlantic

Monthly temperature-salinity diagrams for 1957 have demonstrated that three surface oceanic "water bodies" were consistently present in the eastern North Atlantic; two are regarded as modified North Atlantic Central water which give rise to the third by mixing. As well in the oceanic areas, large and small, high or low salinity patches of water were common. Effects of seasonal climatic fluctuations differed in the several oceanic water bodies. In coastal waters, differences in properties and in seasonal and annual cycles of the properties distinguish the waters from the North Sea, English Channel and the western entrance to the Channel.The geographic distributions of the oceanic waters are consistent with "northern" and "southern" water bodies mixing to form a "transitional" water. Within this distribution there are short-term changes in boundaries and long-term (seasonal) changes in size of the water bodies.Water in the western approaches to the English Channel appeared to be influenced chiefly by the mixed, oceanic transitional water; oceanic influences in the North Sea appear to have been from northern and transitional waters.

scholarly journals Climate-Driven Change in the North Atlantic and Arctic Oceans Can Greatly Reduce the Circulation of the North Sea

2018 ◽  
Vol 45 (21) ◽  
pp. 11,827-11,836 ◽  
Author(s):  
Jason Holt ◽  
Jeff Polton ◽  
John Huthnance ◽  
Sarah Wakelin ◽  
Enda O'Dea ◽  
...  
Keyword(s):  
North Sea ◽  
North Atlantic ◽  
The North ◽  
The North Sea ◽  
The North Atlantic

scholarly journals The carbon budget of the North Sea

2005 ◽  
Vol 2 (1) ◽  
pp. 87-96 ◽  
Author(s):  
H. Thomas ◽  
Y. Bozec ◽  
H. J. W. de Baar ◽  
K. Elkalay ◽  
M. Frankignoulle ◽  
...  
Keyword(s):  
Atlantic Ocean ◽  
Continental Shelf ◽  
North Sea ◽  
North Atlantic ◽  
Carbon Budget ◽  
North Atlantic Ocean ◽  
Carbon Sink ◽  
The North ◽  
The North Sea ◽  
The North Atlantic

Abstract. A carbon budget has been established for the North Sea, a shelf sea on the NW European continental shelf. The carbon exchange fluxes with the North Atlantic Ocean dominate the gross carbon budget. The net carbon budget – more relevant to the issue of the contribution of the coastal ocean to the marine carbon cycle – is dominated by the carbon inputs from rivers, the Baltic Sea and the atmosphere. The North Sea acts as a sink for organic carbon and thus can be characterised as a heterotrophic system. The dominant carbon sink is the final export to the North Atlantic Ocean. More than 90% of the CO2 taken up from the atmosphere is exported to the North Atlantic Ocean making the North Sea a highly efficient continental shelf pump for carbon.

scholarly journals North Atlantic storm driving of extreme wave heights in the North Sea

2017 ◽  
Vol 122 (4) ◽  
pp. 3253-3268 ◽  
Author(s):  
R. J. Bell ◽  
S. L. Gray ◽  
O. P. Jones
Keyword(s):  
North Sea ◽  
North Atlantic ◽  
Extreme Wave ◽  
The North ◽  
Wave Heights ◽  
The North Sea

scholarly journals Synchronous ecological regime shifts in the central Baltic and the North Sea in the late 1980s

2005 ◽  
Vol 62 (7) ◽  
pp. 1205-1215 ◽  
Author(s):  
J. Alheit ◽  
C. Möllmann ◽  
J. Dutz ◽  
G. Kornilovs ◽  
P. Loewe ◽  
...  
Keyword(s):  
North Sea ◽  
North Atlantic ◽  
Climatic Variability ◽  
Regime Shifts ◽  
Trophic Levels ◽  
Copepod Species ◽  
The North ◽  
The North Sea ◽  
The North Atlantic ◽  
Low Levels

Abstract The index of the North Atlantic Oscillation, the dominant mode of climatic variability in the North Atlantic region, changed in the late 1980s (1987–1989) from a negative to a positive phase. This led to regime shifts in the ecology of the North Sea (NS) and the central Baltic Sea (CBS), which involved all trophic levels in the pelagial of these two neighbouring continental shelf seas. Increasing air and sea surface temperatures, which affected critical physical and biological processes, were the main direct and indirect driving forces. After 1987, phytoplankton biomass in both systems increased and the growing season was extended. The composition of phyto- and zooplankton communities in both seas changed conspicuously, e.g. dinoflagellate abundance increased and diatom abundance decreased in the CBS. Key copepod species that are essential in fish diets experienced pronounced changes in biomass. Abundance of Calanus finmarchicus (NS) and Pseudocalanus sp. (CBS) fell to low levels, whereas C. helgolandicus (NS) and Temora longicornis and Acartia spp. (CBS) were persistently abundant. These changes in biomass of different copepod species had dramatic consequences on biomass, fisheries, and landings of key fish species: North Sea cod declined, cod in the CBS remained at low levels, and CBS sprat reached unprecedented high biomass levels resulting in high yields. The synchronous regime shifts in NS and CBS resulted in profound changes in both marine ecosystems. However, the reaction of fish populations to the bottom-up mechanisms caused by the same climatic shift was very different for the three fish stocks.

Sign in / Sign up

Export Citation Format

Share Document