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Titel |
Impact of global change on coastal oxygen dynamics and risk of hypoxia |
VerfasserIn |
L. Meire, K. E. R. Soetaert, F. J. R. Meysman |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
1726-4170
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Digitales Dokument |
URL |
Erschienen |
In: Biogeosciences ; 10, no. 4 ; Nr. 10, no. 4 (2013-04-19), S.2633-2653 |
Datensatznummer |
250018208
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Publikation (Nr.) |
copernicus.org/bg-10-2633-2013.pdf |
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Zusammenfassung |
Climate change and changing nutrient loadings are the two main aspects of
global change that are linked to the increase in the prevalence of coastal
hypoxia – the depletion of oxygen in the bottom waters of coastal areas.
However, it remains uncertain how strongly these two drivers will each
increase the risk of hypoxia over the next decades. Through model
simulations we have investigated the relative influence of climate change
and nutrient run-off on the bottom water oxygen dynamics in the Oyster
Grounds, an area in the central North Sea experiencing summer stratification.
Simulations were performed with a one-dimensional ecosystem model that
couples hydrodynamics, pelagic biogeochemistry and sediment diagenesis.
Climatological conditions for the North Sea over the next 100 yr were
derived from a global-scale climate model. Our results indicate that changing
climatological conditions will increase the risk of hypoxia. The bottom water
oxygen concentration in late summer is predicted to decrease by
24 μM or 11.5% in the year 2100. More intense stratification
is the dominant factor responsible for this decrease (58%), followed by
the reduced solubility of oxygen at higher water temperature (27%),
while the remaining part could be attributed to enhanced metabolic rates in
warmer bottom waters (15%). Relative to these climate change effects,
changes in nutrient runoff are also important and may even have a stronger
impact on the bottom water oxygenation. Decreased nutrient loadings strongly
decrease the probability of hypoxic events. This stresses the importance of
continued eutrophication management in coastal areas, which could function as
a mitigation tool to counteract the effects of rising temperatures. |
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