Transcript during

Our working hypothesis and
the restoration work in 2004
Hypothesis for restoration
Average sea level
1.
2.
3.
4.
5.
6.
7.
Remove the dune
Excavating below average sea level for few days
Creating a strong current in the feeding channel
The strong current will excavate the entire lagoon
Eventually the channel will equilibrate with sea level
But, by then the internal channels are excavated
The tides will keep the channels clean
And the mangrove
functioning
Arriving at the site
Most of blocking sand dune removed by a subsequent hurricane
(2 years after the blocking)
Initial of
feeding channel
0.5 m
width
Remaining sand dune
3-m high
2004
Excavated by nature (hurricane in 2003)
Bay
Mangroves
Salicornia
0.5 m
Mini-feeding channel
Manual digging (inaccessible to
mechanical diggers)
Channel widening (first dig)
La Paz
Approx. 6 m
Digging the opening of the channel
Approx. 2 m
Approx. 10 m
Two weeks after
The dig area filled with sediment
and sand from the blocked lagoon
The channel deepened
…and digging again…
….and we repeat the process for the third time….
The sand dune was replaced by wide channel
to allow fast drainage of the lagoonsc
Approx. 5 m
Approx. 10 m
Over 30 m
Stabilization of the entrance against
waves
Local heavy stones (14 m3), no cement was authorized
Job almost done…..
2004
Restoration done completely….
Natural
Salicornia
The native Salicornia was planted for further stabilization of the channel
Also this is important in the struggle to
conserve mangrove- public awarness
July 2004
Visit our next presentation to see
the outcome of the restoration in
2005