Prior survey heat gave no clear current bleaching link in four Atlantic and Pacific coral samples in 2004-2019

We tested whether heat at the previous year’s surveys predicted current coral bleaching after control for current heat. We used 2,535 consecutive-year site pairs from Reef Check in BCO-DMO 773466 version 2. Separate Atlantic and Pacific models for 2004-2010 and 2011-2019 removed site and year effects and controlled depth and survey season in both years. Prior heat slopes were -2.47, +3.74, -0.31 and -0.86 bleaching percentage points per four degree-heating weeks. All four adjusted country-group intervals included zero. The result also held with other error groups and planned sampling checks. Same-month estimates changed signs in two samples and had wider intervals. Neither Atlantic sample had a pair with at least four degree-heating weeks in both years. These selected survey records do not establish a common prior-heat association. They do not show that thermal history has no effect. Heat at survey dates is not annual heat exposure. Missing surveys, surface heat estimates, few error groups and unknown coral composition limit inference. The package gives survey evidence, paired records, code, source hashes and independent checks.

coral bleaching · thermal history · marine heat stress · observation bias · consecutive-year pairs · null result