Volumes 515–516, 15 May 2015, Pages 129–142
The Orinoco megadelta as a conservation target in the face of the ongoing and future sea level rise
Highlights
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- Underpopulated deltas are ignored as conservation targets against sea level rise.
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- We explore potential effects of sea level rise on the Orinoco river megadelta.
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- Models predict drowning of wetlands and biodiversity and cultural losses.
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- Natural compensating factor may allow coastal wetlands to adapt in the short term.
Abstract
Currently,
risk assessments related to rising sea levels and the adoption of
defensive or adaptive measures to counter these sea level increases are
underway for densely populated deltas where economic losses might be
important, especially in the developed world. However, many
underpopulated deltas harbouring high biological and cultural diversity
are also at risk but will most likely continue to be ignored as
conservation targets. In this study, we explore the potential effects of
erosion, inundation and salinisation on one of the world's
comparatively underpopulated megadeltas, the Orinoco Delta. With a 1 m
sea level rise expected to occur by 2100, several models predict a
moderate erosion of the delta's shorelines, migration or loss of
mangroves, general inundation of the delta with an accompanying
submersion of wetlands, and an increase in the distance to which sea
water intrudes into streams, resulting in harm to the freshwater biota
and resources. The Warao people are the indigenous inhabitants of the
Orinoco Delta and currently are subject to various socioeconomic
stressors. Changes due to sea level rise will occur extremely rapidly
and cause abrupt shifts in the Warao's traditional environments and
resources, resulting in migrations and abandonment of their ancestral
territories. However, evidence indicates that deltaic
aggradation/accretion processes at the Orinoco delta due to
allochthonous sediment input and vegetation growth could be elevating
the surface of the land, keeping pace with the local sea level rise.
Other underpopulated and large deltas of the world also may risk
immeasurable biodiversity and cultural losses and should not be
forgotten as important conservation targets.
Keywords
- Biodiversity;
- Climate change;
- Coastal flooding;
- Global warming;
- Hydrochemistry;
- Indigenous cultures;
- Large deltas;
- Neotropic;
- Wetland
Copyright © 2015 Published by Elsevier B.V.
