Un trabajo conjunto del CSIC y la universidad de Southampton estudia la historia de la ría de Vigo y el impacto de los pobladores de sus costas a través del estudio, como si fuesen catas arqueológicas, de los sucesivos estratos de materia orgánica que se han acumulado desde el s. XIX. El estudio pone de manifiesto que, hoy en día, la acumulación de materia orgánica es menor.
El abstract del artículo:
The Ria of Vigo, one of the classical rias of SW Europe, is an environment of high production of organic
matter naturally induced by the Galician upwelling. The organic matter is partly supplied by small rivers
but mainly by sewage plants along the ria shoreline; jointly they contribute 725 t y1 of POC, of which
72% is of anthropogenic origin. The freshwater flux is equivalent to a supply of 5 g m2 yr1 of
allochtonous POC to the ria floor. However the rate of accumulation of POC is dominated by the order of
magnitude higher supply of autochthonous material from the net primary production. The present
accumulation rate of organic matter (49e58 gPOC m2 yr1) is lower than the average supply, estimated
from the sedimentary record, to the ria since the middle of the nineteen Century (>60 gPOC m2 yr1).
This difference may be due to anthropogenic activity or changes in the upwelling pattern. The composition
of the organic matter in the sediment reflects the relative importance of the various sources
(terrestrial-marine). While terrestrial woody materials dominate the inner ria, phytoplankton remains
dominate the remainder of the ria. Rock-Evaluation analysis indicates the inner ria is the site of deposition
of gas-prone material and it is inferred that the outer ria of oil-prone organic matter. The controls
on the accumulation of POC in the rias show many differences to those found in estuaries affected by
anthropogenic activities e.g. agriculture and increasing human population.
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El abstract del artículo:
The Ria of Vigo, one of the classical rias of SW Europe, is an environment of high production of organic
matter naturally induced by the Galician upwelling. The organic matter is partly supplied by small rivers
but mainly by sewage plants along the ria shoreline; jointly they contribute 725 t y1 of POC, of which
72% is of anthropogenic origin. The freshwater flux is equivalent to a supply of 5 g m2 yr1 of
allochtonous POC to the ria floor. However the rate of accumulation of POC is dominated by the order of
magnitude higher supply of autochthonous material from the net primary production. The present
accumulation rate of organic matter (49e58 gPOC m2 yr1) is lower than the average supply, estimated
from the sedimentary record, to the ria since the middle of the nineteen Century (>60 gPOC m2 yr1).
This difference may be due to anthropogenic activity or changes in the upwelling pattern. The composition
of the organic matter in the sediment reflects the relative importance of the various sources
(terrestrial-marine). While terrestrial woody materials dominate the inner ria, phytoplankton remains
dominate the remainder of the ria. Rock-Evaluation analysis indicates the inner ria is the site of deposition
of gas-prone material and it is inferred that the outer ria of oil-prone organic matter. The controls
on the accumulation of POC in the rias show many differences to those found in estuaries affected by
anthropogenic activities e.g. agriculture and increasing human population.