Characterization of metabolic adaptations of planktonic species/assemblages to suboxic/hypoxic conditions off Chile

Title:
Characterization of the metabolic adaptations of
planktonic species/assemblages to the suboxic/hypoxic
conditions in the Humboldt Current System off Chile

The metabolic adaptations of planktonic species to
hypoxic waters associated with the presence of the
Equatorial subsurface water in the epipelagic system of
the Humboldt Current System were unknown previous to the
FONDAP-Humboldt programme.

This work involved determining the type and activity of
the enzymes involved in anaerobic metabolism. The enzymatic
techniques were developed on intertidal (littoral) and
sublittoral species. Several experiments were conducted on
P. laevigatus, an intertidal crustacean, to determine the
presence and activity of lactate dehyrogenase (LDH),
octopine dehydrogenase (OPDH), strombin
dehydrogenase (STRDH), alanopin dehydrogenase (ALPDH) and
alcohol dehydrogenase (ADH). In addition, it's aerobic
respiration was determined under different temperatures
and it's resistance to hypoxic conditions in seawater.

A comprehensive study was undertaken on the sublittoral
polychaete assemblage living under low oxygen conditions
off Concepcion. The techniques developed during the
polychaete and intertidal species experiments, allowed the
testing and standarization of the biochemical techniques.

With this background, the analysis of the biochemical
adaptation to hypoxia of planktonic species was possible.
The pyruvates oxidoreductases in Euphausia mucronata and
Calanus chilensis - two key species of the pelagic
ecosystem off northern Chile - were analyzed.