Primary Production and Standing Crop of Phytoplankton in the Weddell Sea and Drake Passage

2013 ◽  
pp. 87-106 ◽  
Author(s):  
Sayed Z. El-Sayed ◽  
Enrique F. Mandelli
Keyword(s):  
Primary Production ◽  
Standing Crop ◽  
Drake Passage ◽  
Weddell Sea

scholarly journals The Skytrain plate and tectonic evolution of southwest Gondwana since Jurassic times

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Graeme Eagles ◽  
Hannes Eisermann
Keyword(s):  
Tectonic Evolution ◽  
Drake Passage ◽  
Weddell Sea ◽  
Falkland Islands ◽  
South American ◽  
Long Distance ◽  
Oblique Collision ◽  
Scotia Sea ◽  
Continental Extension ◽  
Pacific Margin

AbstractUncertainty about the structure of the Falkland Plateau Basin has long hindered understanding of tectonic evolution in southwest Gondwana. New aeromagnetic data from the basin reveal Jurassic-onset seafloor spreading by motion of a single newly-recognized plate, Skytrain, which also governed continental extension in the Weddell Sea Embayment and possibly further afield in Antarctica. The Skytrain plate resolves a nearly century-old controversy by requiring a South American setting for the Falkland Islands in Gondwana. The Skytrain plate’s later motion provides a unifying context for post-Cambrian wide-angle paleomagnetic rotation, Cretaceous uplift, and post-Permian oblique collision in the Ellsworth Mountains of Antarctica. Further north, the Skytrain plate’s margins built a continuous conjugate ocean to the Weddell Sea in the Falkland Plateau Basin and central Scotia Sea. This ocean rules out venerable correlation-based interpretations for a Pacific margin location and subsequent long-distance translation of the South Georgia microcontinent as the Drake Passage gateway opened.

scholarly journals Terrestrial trophic dynamics in the Canadian Arctic

2003 ◽  
Vol 81 (5) ◽  
pp. 827-843 ◽  
Author(s):  
Charles J Krebs ◽  
Kjell Danell ◽  
Anders Angerbjörn ◽  
Jep Agrell ◽  
Dominique Berteaux ◽  
...  
Keyword(s):  
Primary Production ◽  
Standing Crop ◽  
Net Primary Production ◽  
Canadian Arctic ◽  
Faecal Pellet ◽  
Trophic Dynamics ◽  
Balance Model ◽  
Arctic Ecosystems ◽  
Large Herbivore ◽  
Tundra Ecosystems

The Swedish Tundra Northwest Expedition of 1999 visited 17 sites throughout the Canadian Arctic. At 12 sites that were intensively sampled we estimated the standing crop of plants and the densities of herbivores and predators with an array of trapping, visual surveys, and faecal-pellet transects. We developed a trophic-balance model using ECOPATH to integrate these observations and determine the fate of primary and secondary production in these tundra ecosystems, which spanned an 8-fold range of standing crop of plants. We estimated that about 13% of net primary production was consumed by herbivores, while over 70% of small-herbivore production was estimated to flow to predators. Only 9% of large-herbivore production was consumed by predators. Organization of Canadian Arctic ecosystems appears to be more top-down than bottom-up. Net primary production does not seem to be herbivore-limited at any site. This is the first attempt to integrate trophic dynamics over the entire Canadian Arctic.

Relationships of Fish Yield to Lake Phytoplankton Standing Crop, Production, and Morphoedaphic Factors

1977 ◽  
Vol 34 (12) ◽  
pp. 2271-2279 ◽  
Author(s):  
Ray T. Oglesby
Keyword(s):  
Primary Production ◽  
Standing Crop ◽  
Crop Production ◽  
Fishery Management ◽  
Cold Water ◽  
Phytoplankton Production ◽  
Fish Yield ◽  
Morphoedaphic Index ◽  
Intensively Managed ◽  
Predicted Values

Fish yield is related to annual primary production, summer phytoplankton standing crop, and the morphoedaphic index for lakes representing a wide variety of typologies by a series of models in the form of log-log regressions. Tentative boundary conditions are established by which lakes inappropriate to the models can be excluded. Confidence intervals for predicted values about the mean are given for the fish yield–phytoplankton standing crop regression. From this relation, potential yields for the lakes studied are reduced from a range of 10,000 to one of 25-fold. Efficiencies with which carbon is transferred from primary production to fish yield vary by 2 to 3 orders of magnitude and are highest for small, intensively managed ponds and lowest for large, deep, cold-water lakes. Models based upon fish yield as a function of phytoplankton production or standing crop are inherently more accurate and subject to fewer exceptions than are those related to morphoedaphic factors. The former appear to be capable of substantial refinement but even in their present state might be employed to make useful predictions for groups of lakes. A suggested supplement to existing approaches in fishery management involves the following sequence: (1) use of expectation-variability diagrams to obtain an overview of the problem, (2) selection of an appropriate model or models to predict yield, (3) prediction of a range of yields, and (4) implementation of regulations proved successful for other lakes in the same yield category. Key words: fish, lakes, phytoplankton, morphoedaphic index, fishery management

Pelagic primary production in the Coral and southern Solomon Seas

1996 ◽  
Vol 47 (5) ◽  
pp. 695 ◽  
Author(s):  
MJ Furnas ◽  
AW Mitchell
Keyword(s):  
Primary Production ◽  
Mixed Layer ◽  
Standing Crop ◽  
Central Basin ◽  
Strong Wind ◽  
Surface Mixed Layer ◽  
Barrier Reef ◽  
Near Surface ◽  
Western Margin ◽  
Coral Sea

Phytoplankton primary production was measured around the periphery of the Coral Sea during October 1985 and in the boundary current systems bordering the northern Australian Great Barrier Reef (GBR) and Papuan Barrier Reef (PBR) during October 1985 and June-July 1988. Under strong wind conditions (mean winds 8-12 m s-1), the north-western Papuan Barrier Reef region was characterized by a shallow surface mixed layer, shallow nutriclines (25-75 m) and shallow subsurface chlorophyll maxima. Under low wind stress conditions (mean winds <5 m s-1), the southern and western Coral Sea were also characterized by a shallow surface mixed layer and stable underlying density profiles but deep (>I00 m) nutriclines and deep (60-125 m) subsurface chlorophyll and primary production maxima. Regardless of location, most primary production occurred above the 20% mid-day isolume surface. Phytoplankton standing crop and primary production in all regions were dominated by picoplankton (<2 μm size fraction). Very high primary production rates (1-3 g C m-2 day-1) were measured at a number of stations adjacent to the western margin of the PBR and within the central basin of the Louisiade Archipelago. Evidence for upwelling along the western margin of the PBR was observed under both north-easterly (normal to the reef axis) and south-easterly (parallel to the reef axis) wind regimes; however, surface outcropping of upwelled water did not occur. Oceanic primary production in the Coral Sea is estimated to be between 100 and 200 g C m-2 year-1. Primary production in and around the Louisiade Archipelago appears to be on the order of 200-300 g C m-2 year-1. Near-surface chlorophyll standing crop was generally better correlated with near-surface primary production than was total chlorophyll with total areal primary production.

Nutrients, standing crop and primary production in western coastal waters of the adriatic sea

1995 ◽  
Vol 41 (5) ◽  
pp. 493-513 ◽  
Author(s):  
A Zoppini ◽  
M Pettine ◽  
C Totti ◽  
A Puddu ◽  
A Artegiani ◽  
...  
Keyword(s):  
Primary Production ◽  
Coastal Waters ◽  
Standing Crop ◽  
Adriatic Sea
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