[Coral-List] Loss of reef biodiversity - any recent data?

[Peter Sale]

Hi coral-listers,
I was recently reading some papers concerning the apparent extinction, across the Florida reef tract of Dendrogyra cylindrus, the pillar coral: Chan et al 2019, Front. Mar. Sci. doi: 10.3389/fmars.2019.00218 ; Jones et al 2021, Scient. Rep. doi.org/10.1038/s41598-021-93111-0 ; and Neely et al 2021, Front. Mar. Sci. doi: 10.3389/fmars.2021.656515 .  They reveal, rather convincingly, that Dendrogyra has likely been extirpated throughout Florida by a combination of bleaching and SCTLD between 2015 and 2020.  Chan et al also provide genetic data suggesting the species had been reproductively extinct in Florida (only asexual propagation happening) for 'many' years before that.  Each paper makes clear that the situation may be different elsewhere in the Caribbean.  I summarized what I gleaned from these papers here: http://www.petersalebooks.com/?p=3165

The story provided by these papers has led me to wonder about all the rare species on coral reefs around the world.  Reef ecosystems are characterized by having relatively few common species (across taxa, not just corals) and long tails of rare species.  Dendrogyra has been rare in most locations in its range for decades if not much longer, but it is a large and conspicuous species.  When it disappears, that is obvious.  But most rare species are also small, inconspicuous, even cryptic.  Their disappearance would be a lot harder to detect unless one was actively looking for them.  So, just to add to the problems faced by coral reef systems, how far along the path to biodiversity collapse are they?

Serious question.  If someone has done a lot of work on this topic, meaning I should already know the answer, forgive an old fish ecologist.  (And if the work was done on reef fishes, please let me down gently!)

Peter Sale
University of Windsor (Emeritus)
sale at uwindsor.ca<mailto:sale at uwindsor.ca>
www.petersalebooks.com<http://www.petersalebooks.com>