1 - Instituto de Biologia da UFRJ

these two types of sewage markers, the LABs show a
potential to be a more specific sewage marker, since their
detectable values were only found close to the EACF sewage
(Martins et al., in this volume). The sterols can also be
used in historic analysis of the contribution of the different
forms of organic material (marine, terrestrial, anthropic) to
the sediment, thus assisting in the evaluation of temporal
variations of the biogeochemical processes (Wisnieski et al.,
in this volume).
Among the marine habitats that can be affected by human
activities or even by climate change, the intertidal zone is
the first to suffer from those environmental alterations. The
most conspicuous organism in this region is the gastropod
Nacella concinna, which
has been considered to be a sentinel species due to
its capacity to accumulate metals (Ahn et al., 2002) or
to be sensitive to the effect of pollutants (Ansaldo et al.,
2005). Up till now, no significant anthropic effect
was found in the populations that inhabit Admiralty
Bay, despite a certain accumulation of heavy metals
found in the species, as well as in a number of benthic
invertebrates in the region (Majer et al., in this volume).
However, studies with biochemical biomarkers reveal a
sensibility of several enzymes in this organism, such as
arginases, phosphofructokinase and catalase, to increasing
concentrations of diesel oil (Feijó de Oliveira et al., in this
volume), reinforcing the importance of control methods
for the prevention of oil leaks into the marine environment
of the region.
Even in the sublittoral zone, in water depths of less
than 20-30m, some effect of the effluent of the Station
can be noticed (Montone et al., in press). Fish and benthic
invertebrates undergo alterations over the time, when
submitted to chronic (sewage) or acute impacts (oil leakages,
for example). Among the fish, most of the nothotenioids
are endemic to Antarctica, which increases the ecological
importance in terms of preservation and conservation of
the marine environment. Through the usage of biochemical
and histological biomarkers, possible alterations in those
fishes can be detected. The histological analysis of the fishes
N. coriiceps and N. rossi showed some changes in the liver
and gills which are still of low occurrence, not affecting the
functionality of their organs and as consequence, not having
any lethal significance (Donatti et al., in this volume). The
same seems to occur with the analyses of the plasmatic
composition of these fish, with variation of glucose,
tryglicerides, cholesterol, total protein and albumins more
related to local physical and chemical differences than to
anthropic ones (Rodrigues Junior et al., in this volume).
For the benthic macroinfauna, the main changes occur
in the abundance and dominance of species in a range of
200m from EACF (Montone et al., in press). In spite of the
presence of metals in the sediment, analyses considering the
mobility of some of these metals, revealed that just Arsenic
and Copper show values that could represent some risk
to the biota (Ribeiro et al., in this volume), emphasising
the importance of evaluating the bioavailability of these
substances in order to evaluate the real effect on marine
organisms.
One of the greatest threats to Antarctic marine
biodiversity, with a high degree of endemism, is the
introduction of exotic species, whether through human
action or through the increase of the temperature of the
oceans, allowing the spread of Sub-Antarctic species to
the Antarctic region. The potential of bioinvasion in the
Antarctic environment is directly related to the increase of
human activities in the region, especially those related to
the increase in the traffic of vessels, one of the main vectors
in the introduction of species in the marine environment.
A recent survey (Rocha et al., in this volume) indicated an
intensification of human activities, such as tourism, fishing
for Krill and scientific activity on King George Island, in
the last five years, which could represent a greater risk of
introduction of exotic species.
In this context, a study of the local biodiversity is
important to get to know the degree of vulnerability of
the Antarctic marine biota to invasions of exotic species
in the future. Despite recent efforts related to the marine
benthic species inventory in Admiralty Bay (Siciński et al.,
2011), there is still a lot to do regarding the comprehensive
knowledge of the marine biodiversity of the region.
Recent data regarding the composition of the associated
macrofauna to the kelp Himantothallus grandiflorius
(Campos et al., in this volume), for example, revealed an
abundant and diverse biota, composed mainly of amphipods
and lophophorates, which still need taxonomic refinement
and which could add new species or new records to this
region. Apart from the latter, the interaction between the
94 | Annual Activity Report 2011