“Piscatorial disaster”: the 1946–47 red tide as an inflection point in the science and ecology of Karenia brevis harmful algal blooms on the West Florida Shelf

We examine the historical political ecology of the 1946–47 red tide on the West Florida Shelf, USA, as a turning point in the scientific understanding of the harmful algae blooms (HAB) associated with Karenia brevis, as well as in their frequency and severity. When the HAB appeared in late 1946, there was no consensus about what it should be called, let alone its cause. The slow and inadequate federal and state response, limited by the nascent state of public support for scientific research, frustrated local residents and officials. By the time the HAB finally ended in the fall of 1947, scientists—with crucial support from a small cadre of citizen scientists led by Jay N. “Ding” Darling—had identified, named, and described the phytoplankton, located the mechanism responsible for the morbidity of marine animals in a toxin emitted by the organism, and tentatively identified the proximate factors leading to its seemingly anomalous proliferation. Historical data validate many of their hypotheses regarding the latter, including both natural weather anomalies (heavy rains, high temperatures) and anthropogenic inputs associated with Florida’s postwar economy and ecology (expansions of phosphate mining and sugar farming, increases in sewage effluent accompanying population growth).