The present study aims to examine the combined influence of oxygen deficiency
and low pH conditions on the community parameters and the composition of the
calcifying macrobenthos, besides analyzing its spatial structure, between 2007
and 2014 in the north central Peruvian shelf (3 ° -9 ° S). The decadal changes of
the calcifying macrobenthos were also evaluated against the bottom dissolved
oxygen content between 1976 and 2015. For the bottom pH, simulated data from
the ROMS-PISCES model, which was previously validated and corrected, were
used at a spatial resolution of 1/9°. The oxygen and pH conditions were classified
into four combined categories, evaluating the community parameters of the
calcifying macrobenthos as dependent variables. The highest abundances of
calcifying macrobenthos were recorded south of 6°S, where there is a greater
organic enrichment and oxygen deficiency. Species richness of the calcifying
macrobenthos showed the lowest values at both low pH and oxygen conditions.
Also, diversity indexes were the highest when oxygen was high and pH low. The
bivalve Solemya sp. was the only species that tolerated both hypoxic and low pH
conditions. Finally, bottom oxygenation towards the period 1995 – 2009
corresponds to the increase of crustacean abundance. It is necessary to review
the calcifying macrobenthos diversity and adaptations associated with upwelling
areas.
Ampuero Leon A. A., 2018. Relación del pH y oxígeno disuelto de fondo con la distribución del bentos calcificante de la plataforma Centro – Norte Peruana. MSc thesis, Universidad Peruana Cayetano Heredia, 187 p. Thesis.
