OUTBREAKS OF CARIBBEAN CORAL DISEASE ON THE RISE
Caribbean-area reef researchers and sport divers should be on the lookout for sites with an unusually high percentage of diseased and recently dead corals. Many of you will have heard that corals in Florida are experiencing one of the largest disease outbreaks on record. The outbreak area has since progressed across Florida. Numerous coral species (except the acroporids) have been afflicted, disease prevalence has reached 80% of all colonies present at a site, and a number of coral diseases have been observed.
On July 2018 in collaboration with the authorities of the Parque Nacional Arrecife de Puerto Morelos, we found a reef near Puerto Morelos, Mexico that had a severe outbreak of a coral disease affecting similar species and exhibiting similar patterns as those in Florida. Since then, we have set out to survey other reefs in the Mexican Caribbean and have found that the disease outbreak is spreading quickly across the region.
Below we provide preliminary analyses and photos of our findings. We hope to update this as more data became available.
If you see any evidence of excessive disease levels on your reefs, please make notes and take photos! Include information about: How many corals are infected: (few - some - many; or count sick and unaffected corals to get a prevalence). Note which coral species are affected and at what depths. Please send information to firstname.lastname@example.org
Patterns of tissue mortality and speed of progression.
Comparison between 3, 10, 21 of July 2018 and 28 of August 2018.
Site 'Fish Market', Puerto Morelos, Mexico.
Photo Credits: Lorenzo Alvarez-Filip; Images compiled by Oriane kroenig, Alba Gonzalez-Posada and Crista Ramirez
Disease outbreak across the Mexican Caribbean
So far we have surveyed 3,631 coral colonies in 17 sites, besides sites in Cozumel (that seems to be relatively free of diseases) we found strong evidence showing that the disease outbreak is spreading rapidly across Northern Mexican Caribbean. The most affected species correspond with those previously reported in Florida (see figure below). Furthermore, evidence of new mortality is evident and so far we have seen in the period of just few weeks how coral colonies completely died and are gradually overgrown by turf algae and fleshy macroalgae (see photos below).
Figure 1. Disease prevalence and recent mortality by coral species in the northern Mexican Caribbean. Between 5 and 25 10x1 m transects were carried out at each site (some partially completed). Siderastrea siderea is largely affected by white blotch, Acropora palmata and A. cervicornis by white band and white pox, Orbicella faveolata by the yellow band disease, and the rest of species showed signs of what has been describe as a white plague. Recent mortality is a combination of 'new mortality' (white skeletons without tissue) and 'transitional mortality' (intact skeletons but covered with thin layer of biofilm). Old mortality is when coral skeletons are covered by turf, macroalgae or other benthic organisms (weeks to years after tissue loss).
Spatial distribution of the disease across the Mexican Caribbean
To represent the spatial distribution of the outbreak, we calculated the % of afflicted colonies using only the ten most affected coral species (Meandrina meandrites, Dichocoenia stokesii, Eusmilia fastigiata, Siderastrea siderea, Colpophyllia natans, Orbicella faveolata, Diploria labyrinthiformis, Siderastrea radians, Pseudodiploria strigosa, Montastraea cavernosa). The information can be visualized using the below Geoportal (prepared by Eduardo Navarro and Lorenzo Alvarez-Filip).
Detailed patterns of tissue mortality and speed of progression in two of the most affected sites:
Figure 2. Disease prevalence and recent mortality at the the sites 'Fish Market' and 'Limones', Puerto Morelos, Mexican Caribbean. Data collected on the 11th of july 2018 in the 'Fish Market' and the 24 of July in 'Limones' by: Esmeralda Perez, Nuria Estrada, Ana Molina, Noemi Espinosa, Franciso Medellin, Eduardo Navarro and Lorenzo Alvarez-Filip.
Photos from the site 'Fish Market', Puerto Morelos, Mexico (3 july 2018)
Photo Credits: Esmeralda Perez and Lorenzo Alvarez-Filip
Photos from the site 'Limones', Puerto Morelos, Mexico (24 july 2018)
Photo Credits: Lorenzo Alvarez-Filip