Turbidity, nutrients and phytoplankton primary production in the Oosterschelde (The Netherlands) before, during and after a large-scale coastal engineering project (1980–1990)

Hydrobiologia ◽  
1994 ◽  
Vol 282-283 (1) ◽  
pp. 61-78 ◽  
Author(s):  
L. P. M. J. Wetsteyn ◽  
J. C. Kromkamp
Keyword(s):  
The Netherlands ◽  
Primary Production ◽  
Large Scale ◽  
Coastal Engineering ◽  
Engineering Project ◽  
Phytoplankton Primary Production

The interaction between shellfish culture and ecosystem processes

2001 ◽  
Vol 58 (5) ◽  
pp. 991-1002 ◽  
Author(s):  
Aad Smaal ◽  
Marnix van Stralen ◽  
Egbertha Schuiling
Keyword(s):  
Primary Production ◽  
Negative Correlation ◽  
Large Scale ◽  
Standing Stock ◽  
Significant Negative Correlation ◽  
Engineering Project ◽  
Phytoplankton Species Composition ◽  
Before And After ◽  
Shellfish Culture ◽  
Annual Primary Production

The carrying capacity of the Oosterschelde ecosystem for the production of mussels (Mytilus edulis) was evaluated before and after completion of a large-scale coastal engineering project in 1987. This project caused hydrodynamic and water-quality changes; hence, phytoplankton-species composition changed and phytoplankton turnover increased, but primary production remained the same. In the prebarrier period (1980–1986), condition of mussels showed a significant negative correlation with the annual shellfish standing stock and a significant positive correlation with the annual primary production. The system was exploited at maximum capacity. In the postbarrier period (1987–1997), the significant correlation between mussel condition and primary production remained, but there was no longer a negative correlation between standing stock and condition. This indicates overstocking, but yields were maintained. This was explained by (i) feedbacks of the mussels in the Oosterschelde ecosystem—through their large filtration and nitrogen-regeneration capacity, increased phytoplankton turnover was induced; and (ii) adaptation to the new conditions by the shellfish farmers in their management of the mussel stocks. It was concluded that feedbacks by filter feeders and farmers have to be addressed in estimating the exploitation capacity of ecosystems.

scholarly journals Indian ocean marine biogeochemical variability and its feedback on simulated South Asia climate

2021 ◽  
Author(s):  
Dmitry V. Sein ◽  
Anton Y. Dvornikov ◽  
Stanislav D. Martyanov ◽  
William Cabos ◽  
Vladimir A. Ryabchenko ◽  
...  
Keyword(s):  
Indian Ocean ◽  
Primary Production ◽  
Light Absorption ◽  
Large Scale ◽  
Monsoon Season ◽  
Light Attenuation ◽  
Convective Precipitation ◽  
Phytoplankton Primary Production ◽  
Cascading Effects ◽  
Subsurface Layers

Abstract. We investigate the effect of variable marine biogeochemical light absorption on Indian Ocean sea surface temperature (SST) and how this affects the South Asian climate. In twin experiments with a regional Earth System Model, we found that the average SST is lower over most of the domain when variable marine biogeochemical light absorption is taken into account, compared to the reference experiment with a constant light attenuation coefficient equal to 0.06 m-1. The most significant deviations (more than 1 °C) in SST are observed in the summer period. A considerable cooling of subsurface layers occurs, and the thermocline shifts upward in the experiment with the activated biogeochemical impact. Also, the phytoplankton primary production becomes higher, especially during periods of winter and summer phytoplankton blooms. The effect of altered SST variability on climate was investigated by coupling the ocean models to a regional atmosphere model. We find the largest effects on the amount of precipitation, particularly during the monsoon season. In the Arabian Sea, the reduction of the transport of humidity across the equator leads to a reduction of the large-scale precipitation in the eastern part of the basin, reinforcing the reduction of the convective precipitation. In the Bay of Bengal, it increases the large-scale precipitation, countering convective precipitation decline. Thus, the key impacts of including the full biogeochemical coupling with corresponding light attenuation, which in turn depends on variable chlorophyll-a concentration, include the enhanced phytoplankton primary production, a shallower thermocline, decreased SST and water temperature in subsurface layers, with cascading effects upon the model ocean physics which further translates into altered atmosphere dynamics.

Phytoplankton primary production and nutrients in the Oosterschelde (The Netherlands) during the pre-barrier period 1980–1984

Hydrobiologia ◽  
1990 ◽  
Vol 195 (1) ◽  
pp. 163-177 ◽  
Author(s):  
L. P. M. J. Wetsteyn ◽  
J. C. H. Peeters ◽  
R. N. M. Duin ◽  
F. Vegter ◽  
P. R. M. de Visscher
Keyword(s):  
The Netherlands ◽  
Primary Production ◽  
Phytoplankton Primary Production
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