Algal pigment distribution and primary production in the eastern Mediterranean as derived from coastal zone color scanner observations

1995 ◽  
Vol 100 (C8) ◽  
pp. 16193 ◽  
Author(s):  
David Antoine ◽  
André Morel ◽  
Jean-Michel André
1990 ◽  
Vol 95 (C7) ◽  
pp. 11483 ◽  
Author(s):  
F. E. Müller-Karger ◽  
C. R. McClain ◽  
R. N. Sambrotto ◽  
G. C. Ray

2010 ◽  
Vol 15 (3) ◽  
pp. 353-368 ◽  
Author(s):  
Yannis N. Krestenitis ◽  
Yannis S. Androulidakis ◽  
Yannis N. Kontos ◽  
George Georgakopoulos

2010 ◽  
Vol 7 (1) ◽  
pp. 1131-1165 ◽  
Author(s):  
J. Möbius ◽  
N. Lahajnar ◽  
K.-C. Emeis

Abstract. The enhanced accumulation of organic matter in Eastern Mediterranean sapropels and their unusually depleted δ15N values have been attributed to either enhanced nutrient availability which led to elevated primary production and carbon sequestration or to enhanced organic matter preservation under anoxic conditions. In order to evaluate these two hypothesis we have determined Ba/Al ratios, amino acid composition, N and organic C concentrations and δ15N on sinking particles, surface sediments, eight spatially distributed core records of the youngest sapropel S1 (10-6 ka) and older sapropels (S5, S6) from two locations. These data suggest that (i) temporal and spatial variations in δ15N of sedimentary N are driven by different degrees of diagenesis at different sites rather than by changes in N-sources or primary productivity and (ii) that present day TOC export production would suffice to create a sapropel like S1 under conditions of deep-water anoxia. This implies that both enhanced TOC accumulation and δ15N depletion in sapropels were due to the absence of oxygen in deep waters. Thus preservation plays a major role for the accumulation of organic-rich sediments casting doubt the need of enhanced primary production for sapropel formation.


2006 ◽  
Vol 3 (4) ◽  
pp. 895-959 ◽  
Author(s):  
J.-P. Gattuso ◽  
B. Gentili ◽  
C. M. Duarte ◽  
J. A. Kleypas ◽  
J. J. Middelburg ◽  
...  

Abstract. One of the major features of the coastal zone is that part of its sea floor receives a significant amount of sunlight and can therefore sustain benthic primary production by seagrasses, macroalgae, microphytobenthos and corals. However, the contribution of benthic communities to the primary production of the global coastal ocean is not known, partly because the surface area where benthic primary production can proceed is poorly quantified. Here, we use a new analysis of satellite (SeaWiFS) data collected between 1998 and 2003 to estimate, for the first time at a nearly global scale, the irradiance reaching the bottom of the coastal ocean. The following cumulative functions provide the percentage of the surface of the coastal zone receiving an irradiance greater than Ez: PaNon-polar=28.80−16.69 log10(Ez)+0.84 log102(Ez)+0.83 log103(Ez) PaArctic=16.01−15.67 log10(Ez)+2.03 log102(Ez)+1.00 log103(Ez) Data on the constraint of light availability on the major benthic primary producers and net primary production are reviewed. Some photosynthetic organisms can grow deeper than the nominal bottom limit of the coastal ocean (200 m). The minimum irradiance required varies from 0.4 to 5.1 mol photons m−2 d−1 depending on the group considered. The daily compensation irradiance of benthic communities ranges from 0.24 to 4.4 mol photons m−2 d−1. Data on benthic irradiance and light requirements are combined to estimate the surface area of the coastal ocean where (1) light does not limit the distribution of primary producers and (2) net community production (NCP, the balance between gross primary production and respiration) is positive. Positive benthic NCP can occur over 37% of the global shelf area. The limitations of this approach, related to the spatial resolution of the satellite data, the parameterization used to convert reflectance data to irradiance, and the relatively limited biological information available, are discussed.


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