Coral-reef ecosystems have faced escalating global and local stressors over 50 years, including more frequent and severe bleaching events. Bleaching, caused by the loss of algal endosymbionts, results from photo-oxidative stress triggered by high solar radiation, especially in water temperatures exceeding c. 30°C. Sampling benthic foraminifera from the Florida Reef Tract in the early 1990s revealed unusual symbiont loss patterns in Amphistegina, a globally distributed symbiont-bearing foraminifera common on reefs. This and subsequent studies of their biology and ecology, along with other reef condition indicators, led to proposed metrics such as the Amphistegina Bleaching Index (ABI), Foraminifera in Reef Assessment and Monitoring (FoRAM) Index, and Sediment Constituent (SEDCON) Index. In June 2024, we sampled Tennessee Reef in the Middle Keys (Florida Keys, USA) to compare these bioindicators with data from the previous 30+ years. While FoRAM and SEDCON indices suggested somewhat improved water quality, the ABI showed exceptional bleaching in Amphistegina gibbosa, coinciding with earlier onset of water temperatures above 30°C.