Revista Chilena de Historia Natural 80 (2): 173-186, 2007
RESEARCH ARTICLE
Is there redundancy in bioengineering for molluscan assemblages on the rocky shores of
central Chile?
Bioengineers modify habitats via their own physical structures and substantially increase
local diversity in marine ecosystems. On rocky shores, there are large overlaps in the composition of communities associated with
bioengineers that form complex mat-like habitats. We investigated the potential for redundancy in habitat provision by these types of
habitats by comparing diverse molluscan assemblages associated with Perumytilus purpuratus mussel beds and algal
turfs of Corallina officinalis var. chilenis, Gelidium chilense and Gastroclonium
cylindricum. At three times between September 2003 and January 2004, we sampled the molluscan assemblages associated
with each bioengineer at similar tidal heights on two rocky shores on the coast of central Chile. Of the 31 molluscan species identified,
30 were found in Corallina and 19-22 were identified from the other habitats. The pool of species found associated with
each bioengineer overlapped greatly, demonstrating the potential for redundancy in habitat provision and little habitat specificity.
However, multivariate and univariate analyses showed all bioengineers except Gastroclonium contained a unique
molluscan assemblage for at least one time of sampling because of variation in frequency of occurrence, richness and total
abundance. Recent studies have highlighted many anthropogenic and natural processes that directly influence the diversity and
composition of bioengineering species on rocky shores. We demonstrate that the loss of any particular bioengineer would not
substantially alter the overall pool of molluscan species on the rocky shores of Chile. The loss of any bioengineer except
Gastroclonium would, however, result in decreased local biodiversity because the molluscan assemblages in
Perumytilus, Corallina and Gelidium, each contained a significantly different community structure
for at least one time of sampling.
Key words:
bioengineer, molluscs,
redundancy, coralline turfs, mussels, rocky shores, Chile
