[Coral-List] New paper on Caribbean reef classification, distribution and geomorphology

[Paul Blanchon]

With apologies for the blatant self promotion... we are pleased to announce
the following open-access publication which may be of interest:

Blanchon P, Medina-Valmaseda AE, Islas-Domínguez E, Guerra-Castro E,
Blakeway D, Garza Pérez JR, et al. (2022) Linear breakwater reefs of the
greater Caribbean: Classification, distribution & morphology. PLoS ONE
17(11): e0270053. https://doi.org/10.1371/journal.pone.0270053

YouTube video: https://youtu.be/dIr67dFwtO4

Abstract:
Geomorphic differences among Caribbean reefs have long been noted. These
differences are considered to reflect the presence of reefs in different
stages of development, following an incomplete recovery from rapid
deglacial sea-level rise. But the possibility that these reflect real
developmental differences caused by variation in wind, wave, and climate
regime, has never been fully considered. Here, for the first time, we
quantify the geomorphology and distribution of Greater Caribbean reefs
using satellite images in Google Earth and public-domain bathymetry. To do
this, we first standardise their classification based on shallow
geomorphology, substrate depth, and physiographic setting, and then count
and categorise the total number of reefs. These data show a total of 1023
linear breakwater reefs with a combined length of 2237 km. Of this total
length, 80% are fringing reefs, 16% are barriers and 4% are faros and
atolls. In terms of categories, there are 16 reef subtypes present, but
only 9 are common. Their distribution, however, is not uniform. In
particular, flat-subtypes form 60% of breakwater reefs in southern regions,
but are less common in northern regions where crest-subtypes dominate
(80%). To distinguish the geomorphology of these common reef subtypes, we
collect size- and length-related morphometric data from their main reef
zones. These data reveal that flat and crest subtypes also have
morphometric differences: flat subtypes have well-constrained morphologies
with statistically consistent unimodal morphometrics characterised by large
back-reef zones, smaller and steeper reef fronts, and more sinuous and
persistent crestlines. Crest subtypes, by contrast, have multimodal
morphometrics suggesting less consistent morphologies (or unresolved
subtypes), and are characterised by crestlines with lower sinuosity and
more variable back-reef and reef-front areas and slopes. These differences
in geomorphology and distribution imply that flat- and crest-subtypes are
neither successional stages of a single reef type, nor a genetically
related sequence of types, but distinct reefal geoforms with different
modes of development. In subsequent work we will explore what controls
these differences.


Saludos,
Paul.

Paul Blanchon Ph.D.
Marine Geoscience Lab., Reef Systems Unit, Puerto Morelos,
Institute of Marine Sciences & Limnology
National Autonomous University of Mexico (UNAM)
Tel: +52  (998) 87-10009
Email blanchons at gmail.com
Web: sites.google.com/view/reefgeoscience/home
Google Scholar
<https://scholar.google.com.mx/citations?%20user=XZZo_&user=XZZo_UEAAAAJ>