Coral-associated richness
Our study of Pocillopora colonies in the central Galápagos rocky
subtidal ecosystem contribute to the growing number of studies that show
that finger corals host a diverse assemblage of fish and
invertebrates. Our surveys showed that recently recoveredPocillopora colonies supported up to 20 observed species
(randomized observed species richness), and up to 41 total estimated
species (Chao 1 estimated species richness), including nine known fishes
and 11 known mobile macroinvertebrate species. Dead colonies of the same
Genus supported an even greater diversity of up to 25 observed species
and 61 total estimated species, including seven known fishes and 18
known mobile macroinvertebrate species. Even so, these species estimates
are an underestimate of the actual diversity of the entire community of
associated species, since (for ethical considerations) we chose not to
collect corals and exhaustively census the mobile fauna living in the
interstices of the coral, or the sessile invertebrates and algae that
colonized the dead Pocillopora colonies.
The biodiversity of communities associated with Pocilloporacorals has been extensively studied in other tropical regions, and the
range of our estimated values of species richness (20-41 species
associated with live corals depending on the mode of analysis) falls
within the range (though at the lower end) of published values ofPocillopora communities in other regions. The seminal work of
(Abele & Patton 1976) demonstrated that off the Pacific coast of Panama
(close to the Galápagos study region), Pocillopora colony area
predicted the species richness of the decapod community associated with
the corals, supporting 61 total species of decapods. Subsequent work has
found that 36-127 species were found associated with Pocilloporacorals at locations from the Red Sea to Hawaii (Britayev et al. 2017).
Consequently, declines in finger coral habitats appear to represent an
important loss of foundational habitat for a diverse assemblage fishes
and invertebrates.