We have many HABs in the Arabian Gulf such as Dinophsis ( caudate, Miles , rotundata), Pyrodinium bahamenseV. compresum, Trichodesmum , Nitzschia pungens, Prorocentrun( minimum, gracilis, lima )
maybe the toxin-producing dinoflagellate Cochlodinium
See :
Zhao et al. (2015) Characterization of harmful algal blooms (HABs) in the Arabian Gulf and the Sea of Oman using MERIS fluorescence data. ISPRS Jurnal pf Photogrammetry and Remote Sensing, Vol 101: 125-136.
The red tide phenomenon has started from 2008 in PERSIAN Gulf. It started from southern coach of Hormoz Island and spread to other parts of the PERSIAN Gulf. After observing this phenomenon research team of the PERSIAN Gulf Institute of ecology began their studies on this phenomenon. You can get more information from this team. I have seen a report of their studies and it seems that main cause of harmful algal bloom of the PERSIAN Gulf is Cochlodinium polykrikoides. But unfortunately I don't know about electromagnetic spectrum of that. The attached photo belongs to this dinoflagellate. The PDF could be useful for you.