Publication Date:
2022-05-25
Description:
Author Posting. © The Authors, 2005. This is the author's version of the work. It is
posted here by permission of Elsevier B. V. for personal use, not for redistribution. The
definitive version was published in Estuarine, Coastal and Shelf Science 65 (2005): 587-600, doi:10.1016/j.ecss.2005.07.005.
Description:
Here we present the first reconstruction of changes in surface primary production during the last
century from the Puyuhuapi fjord in southern Chile, using a variety of parameters (diatoms, biogenic
silica, total organic carbon, chlorins, and proteins) as productivity proxies. Two sediment cores from
the head and the center of the fjord were analyzed and compared to gain insights on past changes in
productivity in these two different depositional environments. Higher sedimentation rates found at the
head of the fjord result from the combination of a shallower water column and a restricted circulation
by the occurrence of a sill. Additionally, sediment mixing depths estimated from 210Pb data suggest that
suboxic conditions may dominate the bottom water and the sediment-water interface in this location.
Productivity of the Puyuhuapi fjord during the last century was characterized by a constant
increase from the late 19th century to the early 1980s, then decreased until the late-1990s, and then rose
again to present-day values. The influence of rainfall on productivity was most noticeable during
periods of low rainfall, which coincided with decreased overall productivity within the Puyuhuapi fjord.
Simultaneous variations in productivity and rainfall in the study area suggest that marine productivity
could respond to atmospheric-oceanic interactions at a local scale. At a regional scale, marine
productivity of the area may be related to other large-scale processes such as the El Niño Southern
Oscillation.
Description:
We are grateful to the Ministerio de Hacienda de Chile (Chilean Ministry of Treasury) and the
National Oceanographic Committee (CONA) for financial support to carry out the Cimar-7 Fiordo
Program (Grant C7F 01-10 to Silvio Pantoja), the FONDAP-COPAS Center, and Grant
200.031.085-1 (UdeC) for financial support. Sepúlveda was funded by a scholarship from the Graduate School of the University of
Concepción and by the FONDAP-COPAS Center. Additional support was given by Fundación Andes
through the Woods Hole Oceanographic Institution/University of Concepción agreement.
Keywords:
Paleoproductivity
;
Organic matter
;
Fjords
;
Chile
Repository Name:
Woods Hole Open Access Server
Type:
Preprint
Format:
603977 bytes
Format:
application/pdf
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