Since these sargassum observations are so wide spread (From the Lesser
Antilles to TX) it would seem to either be widespread and
coincidentally / simultaneously local events, or there is a large scale
event (or synergistic events) influencing the system at large(?)

Not understanding the system in detail (delivery, chemistry of
etc)...but posing a question; /could variability in dust events be a
catalyst for such blooms / and or could such dust be affecting rainfall
/ sea surface temperature patterns causing similar ends/(?) [...]