Zooplankton
13
-
Pacific
Atlantic _
50
\s?)}/,\!2:::J 0 ~(. ' \
:)C ~:5(j'
~ (l
100
150
poe
~
~ ____ ~~ ____ ~ ____ ~ ____ L -__ ~ ________ L -__________ ~
Fig. 1.15. Distribution of the organic fraction of seston (PaC) in the Straits of Magellan in the austral summer
1991. (After Povero et al. 1991)
Pacific
Atlantic _
- '20
·50
·100
·150
(
.~~ ____ ~ ____________ ~ ____ ~ __ ~~ ______ L -__________ ~
Fig. 1.16. Distribution of the available organic fraction of seston (PaM) in the Straits of Magellan during the
austral summer 1991. (After Povero et al. 1991)
were characterized by phytoplankton populations which were distinct from those found
in adjacent oceanic areas. The most characteristic feature of these populations was
the numerical dominance and relative
importance, in terms of biomass, of very
small «5 Jlm) eukaryotic algae. Among
these, an important role was played by nonflagellate species, such as very small coccoid
cells and diatoms.
1.8 Zooplankton
There are very few studies on the zooplankton
of the Straits of Magellan. Arcos (1974)
identified the Calanoid copepods of the
Magellan region along the southern coast of
Chile but not within the Straits proper.
Mazzocchi and lanora (1991) were the first to
describe the copepod assemblages of the
Straits of Magellan. They identified a total of
26 species during the austral spring 1989.
Lowest values were recorded in the Atlantic