Update of SCTLD in Southeast Florida

Update of SCTLD In Southeast Florida, May 22, 2019.
Submitted by Brian Walker, Nova Southeastern University, Florida

M. cavernosa with expanding SCTLD lesion that has crossed its firebreak.
Photo by  © Brian Walker 2019

Over the last few weeks in Southeast Florida, we may be seeing the SCTLD disease on Montastraea cavernosa (MCAV) spreading more rapidly than before, and now large Orbicella are getting reinfections and needing more re-treatments. We have many firebreak margins with amoxicillin treatments that have lost a lot of tissue within a week. The good news is the firebreaks are holding at the early (two weeks) stage.

On many of our MCAV, the tissue is sloughing off rapidly without a bleached tissue margin. See attached example in which the disease crossed our firebreak and spread over this coral in about 5 weeks. Also notice several single, new disease spots way ahead of the margin. Anecdotally, the overall disease prevalence in areas our strike teams have been diving (nearshore northern Miami-Dade) is still relatively low.

This seems to be following the same pattern as last year when more treatments were required in May and June, and once again seems to correspond to the onset of the rainy season (we had a very rainy end of April).