Life cycle strategies and seasonal variations in distribution and population structure of four dominant calanoid copepod species in the eastern Weddell Sea, Antarctica

1994 ◽  
Vol 16 (11) ◽  
pp. 1543-1566 ◽  
Author(s):  
S.B. Schnack-Schiel ◽  
W. Hagen
2018 ◽  
Vol 10 (3) ◽  
pp. 1457-1471 ◽  
Author(s):  
Astrid Cornils ◽  
Rainer Sieger ◽  
Elke Mizdalski ◽  
Stefanie Schumacher ◽  
Hannes Grobe ◽  
...  

Abstract. This data collection originates from the efforts of Sigrid Schnack-Schiel (1946–2016), a zooplankton ecologist with great expertise in life cycle strategies of Antarctic calanoid copepods, who also investigated zooplankton communities in tropical and subtropical marine environments. Here, we present 33 data sets with abundances of planktonic copepods from 20 expeditions to the Southern Ocean (Weddell Sea, Scotia Sea, Amundsen Sea, Bellingshausen Sea, Antarctic Peninsula), one expedition to the Magellan region, one latitudinal transect in the eastern Atlantic Ocean, one expedition to the Great Meteor Bank, and one expedition to the northern Red Sea and Gulf of Aqaba as part of her scientific legacy. A total of 349 stations from 1980 to 2005 were archived. During most expeditions depth-stratified samples were taken with a Hydrobios multinet with five or nine nets, thus allowing inter-comparability between the different expeditions. A Nansen or a Bongo net was deployed only during four cruises. Maximum sampling depth varied greatly among stations due to different bottom depths. However, during 11 cruises to the Southern Ocean the maximum sampling depth was restricted to 1000 m, even at locations with greater bottom depths. In the eastern Atlantic Ocean (PS63) sampling depth was restricted to the upper 300 m. All data are now freely available at PANGAEA via the persistent identifier https://doi.org/10.1594/PANGAEA.884619.Abundance and distribution data for 284 calanoid copepod species and 28 taxa of other copepod orders are provided. For selected species the abundance distribution at all stations was explored, revealing for example that species within a genus may have contrasting distribution patterns (Ctenocalanus, Stephos). In combination with the corresponding metadata (sampling data and time, latitude, longitude, bottom depth, sampling depth interval) the analysis of the data sets may add to a better understanding how the environment (currents, temperature, depths, season) interacts with copepod abundance, distribution and diversity. For each calanoid copepod species, females, males and copepodites were counted separately, providing a unique resource for biodiversity and modelling studies. For selected species the five copepodite stages were also counted separately, thus also allowing the data to be used to study life cycle strategies of abundant or key species.


2018 ◽  
Author(s):  
Astrid Cornils ◽  
Rainer Sieger ◽  
Elke Mizdalski ◽  
Stefanie Schumacher ◽  
Hannes Grobe ◽  
...  

Abstract. Copepods are often the predominant taxa in marine zooplankton and play an important role in the food web as intermediators between primary producers, the microbial loop and higher trophic levels. Due to their short life cycles and their rapid response to changing environments they are good indicators for ecosystem health and status. Investigating the effects of environmental change on planktonic copepods and thus the pelagic ecosystem requires data on species abundance and distribution. Here, we present 33 data sets with abundance and occurrence of planktonic copepods from 20 expeditions to the Southern Ocean (Weddell Sea, Scotia Sea, Amundsen Sea, Bellingshausen Sea, Antarctic Peninsula), one expedition to the Magellan region, one latitudinal transect in the Eastern Atlantic Ocean, one expedition to the Great Meteor Bank and one expedition to the northern Red Sea and Gulf of Aqaba. In this data compilation a total of 349 stations between 1985 and 2005 were archived. These data sets are now freely available at PANGAEA via the persistent identifier doi:10.1594/PANGAEA.884619. During most expeditions depth-stratified samples were taken with a Hydrobios multinet with 5 or 9 nets. On few occasions a Nansen or Bongo net was deployed. The deepest sample reached down to 2880 meter. As metadata sampling date and date/time, latitude, longitude, bottom depth, sampling depth interval, volume of filtered water and information of the net type and mesh size were recorded. Abundance and distribution data for 284 calanoid copepod species and 28 taxa of other copepod orders are provided. The taxonomic concept was consistent throughout the data sets. The density of calanoid copepod species was separately counted for females, males and copepodites. For selected species also the individual copepodite stages were counted.


2021 ◽  
Author(s):  
Elise Droste ◽  
Melchor González Dávila ◽  
Juana Magdalena Santana Casiano ◽  
Mario Hoppema ◽  
Gerd Rohardt ◽  
...  

<p>Tides have a large impact on coastal polynyas around Antarctica. We investigate the effect of semi-diurnal tidal cycles on the seawater carbonate chemistry in a coastal polynya hugging the Ekström Ice Shelf in the south-eastern Weddell Sea. This region experiences some of the strongest tides in the Southern Ocean. We assess the implications for the contribution of coastal polynyas to the carbon dioxide (CO<sub>2</sub>) air-sea flux of the Weddell Sea.</p><p>Two site visits, in January 2015 and January 2019, are intercompared in terms of the dissolved inorganic carbon (DIC) concentration, total alkalinity, pH, and CO<sub>2</sub> partial pressure (pCO<sub>2</sub>). The tides induce large variability in the carbonate chemistry of the coastal polynya in the austral summer: DIC concentrations vary between 2174 and 2223 umol kg<sup>-1</sup>.</p><p>The tidal fluctuation in the DIC concentration can swing the polynya from a sink to a source of atmospheric CO<sub>2 </sub>on a semi-diurnal timescale. We attribute these changes to the mixing of different water masses. The amount of variability induced by tides depends on – and is associated with – large scale oceanographic and biogeochemical processes that affect the characteristics and presence of the water masses being mixed, such as the rate of sea ice melt.</p><p>Sampling strategies in Antarctic coastal polynyas should always take tidal influences into account. This would help to reduce biases in our understanding of how coastal polynyas contribute to the CO<sub>2</sub> uptake by the Southern Ocean.</p>


2011 ◽  
Vol 45 (33-34) ◽  
pp. 2081-2094 ◽  
Author(s):  
Ghasem M. Kashani ◽  
Alireza Sari ◽  
Shidokht Hosseinie ◽  
Masoumeh Malek ◽  
Ehsan Entezari

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