Harmful Algal Blooms (HAB’s) in Marine Mammals – Part 2. Dr Rick Last – Specialist Veterinary Pathologist. Harmful Algal Blooms (HAB’s) in Marine Mammals – Part 2.   Saxitoxins, Brevetoxins, Cyanobacteria toxins and Okadaic Acid. HAB diagnostic sampling. Dr Rick Last – Specialist Veterinary Pathologist. As a recap on Part 1. Biotoxins that pose the greatest real or potential threat to marine mammal health include: Domoic acid (produced by diatoms of Pseudo-nitzschia ) Saxitoxins (produced mainly by dinoflagellates Gymnodinium catenatum, Pyrodinium bahamense, and Alexandrium tamarense) Brevetoxins (produced by the dinoflagellate Karenia brevis) Cyanobacteria algal toxins. Okadaic acid (produced [...]