INVESTIGADORES
LARA Ruben Jose
capítulos de libros
Título:
Mangroves in the Change: The Need of New Synthesis of Climate, Ecohydrology and Biomedical Research
Autor/es:
LARA, R.J.
Libro:
Mangroves: Ecology, Biology and Taxonomy
Editorial:
. Nova Science Publishers, Inc.
Referencias:
Lugar: New York; Año: 2010; p. 287 - 295
Resumen:
Besides the classical
ecological, hydrological and biogeochemical studies, microbiological investigations
in mangroves have been hitherto mostly related to material transformation and fluxes,
and little is known about pathogen dynamics in their different compartments. South
Asia and Brazil
embrace the largest unitary mangroves worldwide. Although Sunderbans mangroves
have been related since ancient times to endemic cholera, there are no
systematic studies establishing causal links between the yearly hydrological and biogeochemical cycles
in its waters and the seasonal dynamics of Vibrio
cholerae. In Amazonia, although this region has been affected by cholera in the past, the
disease never developed an endemism as around the Bay of
Bengal.A comparison between Sunderbans and Amazonian mangroves as Vibrio habitats would provide a
deeper insight into the links between wetland dynamics, pathogen diversity and
incidence of diarrheal diseases. The environmental setting of both regions is
similar: large mangroves, high riverine discharge and sediment load. Thus, a major question is: Why is cholera
endemic in mangrove regions in South Asia and not in tropical South
America? Is this mainly a biodiversity, biogeochemical or
social/demographic issue?
Mangrove waters and
sediments are rich in chitinaceous organisms, such as zooplankton, shrimps and
crabs. V. cholerae can acquire new
genetic material by natural transformation during growth on chitin. Thus,
natural competence occurring in chitin-attached bacterial communities can act
as driver of V. cholerae?s evolution,
and the natural chitin abundance in mangroves can favor pathogen mutations. Further,
aquaculture in or close to mangroves is increasing worldwide and vibrioses are
common diseases affecting shrimp ponds. Thus, aquaculture can play a double
role in Vibrio dynamics in mangroves:
by the high density of chitinaceous substrate and by the pathogen abundance in
the ponds. Further, dam construction ?and likely sea-level rise- facilitates
salt intrusion into Bay of Bengal estuaries,
resulting in land use shifts from rice cultivation to shrimp farming. Nothing
is known about these interactions or about the effect of increasing eutrophication
on pathogen dynamics in mangroves.
Another knowledge gap
is the dynamics of mangrove regeneration under conditions of increasing storm frequency
and intensity or after a tsunami. A discussion
about a new paradigm on the stability of aquatic ecosystems is urgently needed.
Natural mangrove regeneration may not keep pace with a higher incidence of
catastrophic events and with the dynamics of human communities relying on coastal
resources for subsistence. Sustainability is necessary but not enough, and it
is crucial to get endangered coastal regions on a pathway to increased
robustness.
Thus, the knowledge on techniques for regeneration of degraded mangrove
ecosystems or creation of new forests along endangered coastal stripes has to
be improved, as well as the understanding of the consequences of introducing
such changes in the environmental setting.