CONTENT - International Society of Zoological Sciences

S19 ICZ2008 - Abstracts
Honeybees as bioindicators in urban areas (Seine-Saint-Denis,
France)
Agnès Rortais, Yves Loublier and Gérard Arnold
Laboratoire Populations, Génétique, Evolution CNRS, UPR 9034,
Avenue de la Terrasse, 91198 Gif-sur-Yvette – France
Foraging activity in honeybees is an important component of the
colony’s life. When visiting plants, honeybees bring back products
(nectar, pollen) to the colonies that mirror the diversity and quality
of the environment. In addition, honeybees being very sensitive to
environmental pollution, any behavioural changes among foragers
are an indicator of an environmental stress. Based on these
features, the present study describes tested methods for the use of
honeybees as bioindicators, in particular in urban areas.
In the region of Ile-de-France, three sites showing different types
of anthropogenic disturbances (urban, agricultural and seminatural)
were selected. In these sites, five hives were monitored in
2007 and 2008 during the flowering period (April to September). In
particular, pollen traps were set at two hives and bee traps, bee
counters, cameras and scales on the three other hives. Detail
analyses were conducted on pollen identification, forager’s activity
and behaviour, and colony’s development
Preliminary data are described for the urban site based in the
Seine-Saint-Denis department which is recognized for its activities
in the field of urban biodiversity conservation (ODBU: Observatoire
Départemental de la Biodiversité Urbaine – Departmental
Observatory of urban biodiversity).
One of the main striking results of this study is the great taxonomic
richness found at this site and the presence of exotic species.
These results highlight the importance of conserving urban areas
as reservoirs of nectariferous and melliferous resources for
pollinators. Further studies need to identify the relative importance
of generalist (like honeybees) versus specialist pollinators in such
a floral environment.
Uncertainty and ignorance in assessing environmental effects
of toxic chemicals: the example of endocrine disruption
Helmut Segner
Centre for Fish and Wildlife Health, University of Bern, Switzerland
Ecotoxicological risk assessment aims to estimate at what
concentrations chemicals may occur in the environment and at
what concentrations they are likely to cause adverse effects in
exposed biota and ecosystems. The toxicological data used as
basis in the risk assessment process are derived mainly from
laboratory tests relying on few “model” species and on apical, nonmechanistic
endpoints. Further, the focus of these tests is on acute
rather than on chronic effects.
The extrapolation from such reductionistic approaches to
environmental scenarios necessarily involves uncertainty.
However, the extrapolation additionally suffers from ignorance on
the biological functions and processes that are at risk by the
exposure to toxic chemicals. As an example to illustrate the
inherent problems in assessing the impact of chemicals on biota,
the presentation will discuss the case of endocrine disruption, i.e.
the disturbance of hormone systems by environmental compounds.
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Cellular damage induced by organic mercury and its
prevention by combination therapy
Varsha Singh 1 , Sadhana Shrivastava 1 , Mohammed Abdullah 2 and
Sangeeta Shukla 1
1 Reproductive Biology and Toxicology Laboratory, School of
Studies in Zoology, Jiwaji University, Gwalior-474011, India
2 Trace Element - Institute for UNESCO, 1 place de l'Ecole, BP
7021, 69342 Lyon Cedex 07, France
Heavy metals such as cadmium, mercury (Hg), lead etc. are major
environmental and occupational hazards. These non-essential
elements are toxic even at very low doses and non-biodegradable
with a very long biological half-life. Mercury is one of these heavy
metals, which leads to several health hazards in human and
animals. In this study, we addressed the putative uptake pathways
involved along the nephrons, the mechanisms of intracellular
sequestration and detoxification of mercury. We also tackled the
question of the possible therapeutic means to decrease its toxic
effects. For this purpose, albino rats were intoxicated with mercury
(Dimethyl mercury; 10 mg/kg, p.o., once only). The degree of
kidney damage was evaluated biochemically and
histopathologically. Quantity of SALP, GGT, urea, uric acid, BUN
and creatinine were increased in serum after Hg administration.
Renal lipid peroxidation was raised significantly, whereas GSH
contents and the enzymatic activities of GSH cycle were found to
be declined. Significant accumulation of Hg was also noticed in
kidney. Three days curative treatment of glutathione (GSH; 0.30
mM/kg, i.p.) and its combination with lipoic acid (LA; 100 mg/kg,
p.o) and magnesium (Mg; 10 mg/kg, p.o.) recovered in all the
biochemical estimations. Protective activity of GSH + Mg was
statically compared with GSH + LA and is better in preventing
oxidative stress as confirmed by recouped endoplasmic reticulum
and mitochondrial assembly in ultra structural study. Distribution
study of mercury demonstrated that GSH + Mg exert more
pronounced effects (P < 0.001) rather than GSH + LA and per se
groups.