This project started after the PEMEX tank ship Lázaro Cárdenas II was
stranded in a reef area near Isla Espíritu Santo, B.C.S., destroying
close to one
hectare of coral. After an initial stage of damage diagnosis, determining urgent cleaning and restoration measurements, collaborating with PROFEPA, we finally reached the objective of this project, which is the monitoring stage of the restored coral reef system.
The project pursues to determine the tendency toward recovery, or not,
of the impacted area and after its restoration in a period of 5 years. For
this purpose, we used two approaches: structural and functional.
The structural approach tries to determine if there is a recovery
tendency of the coral area. This is why seasonal monitorings estimate the
artificial reefs (modules) which were set up in the impacted area, assessing
survival, growth of the corals cemented in the modules, and recruiting rate of
corals in the impacted area.
On the other hand, the functional approach focuses on fauna and
flora associated to the restored area; and for this purpose we characterized, by
means of subaquatic census, composition, density, and seasonal variation of the
macrofauna associated to the impacted area specifically mollusks (winkles and
clams), polychetes (polychete worms), crustaceans (crabs and shrimp)
echinoderma (starfish and sea urchin), and fish, as well as the richness and
cover of algae.
To estimate the changes that occur in the restored area as objectively as possible, it is necessary to compare the results with adjacent,
close, and far control areas. This is why the activities are performed in several sites
located in the bay of La Paz as in the bay of Loreto.
In general the results we have obtained up to date are positive in
structural terms because the modules have maintained their integrity, about 70%
of the cemented coral has survived and has grown in similar rates to other
regions. We have also detected a high recruiting rate of corals of the genera Pocillopora and Porites.
In the functional approach, we only have a differential use of the restored and
surrounding areas because of the different groups of organisms, and because the
dispersion speed of the organisms as well as habitat requirements are specific
and are temporarily modulated by the environmental dynamics of each period.