… Like ocean heat-induced red tide and blue green algae (cyanobacteria). The problem of things like cyanotoxins is particularly bad in Florida, but Massachusetts Buzzards Bay has seen its share of problems. Quoting:

• Blue-green algae are laden with microcystins that are a cause of non-alcoholic liver cancer. The algae blooms also produce BMAA (β-Methylamino-L-alanine), a toxin that is linked to neurodegenerative diseases such as Alzheimer’s, ALS and Parkinson’s. Last year, Drs. Paul Cox and James Metcalf of Brain Chemistry Labs reported that microcystin levels in samples from Lake Okeechobee and the St. Lucie canal were 300 times the level recommended as safe by the United Nations.
• BMAA is a documented cause of Alzheimer’s and ALS. The University of Miami Brain Endowment Bank reported that the BMAA toxin is found in the brains of people with neuro-degenerative diseases.
• Dr. David Davis, a neuropathologist at the University of Miami Miller School of Medicine, reported that monkeys fed BMAA developed early symptoms of ALS. Another study, from 2017, documented that monkeys given BMAA developed the amyloid plaque and “tau tangles” that are the symptoms of Alzheimer’s. Last month, Dr. Davis’ team reported that detectable levels of the BMAA toxin were found in the brains of dead dolphins that displayed degenerative damage similar to Alzheimer’s, ALS and Parkinson’s in humans.
• High concentrations of BMAA have been found in the seafood in South Florida waters where blue-green algae blooms occur. Ingestion of BMAA contaminated food is known to lead to Alzheimer’s and ALS.
• Toxins in blue-green algae are airborne: Dr. Elijah Stommel of Dartmouth reported that people living near bodies of water with heavy blue-green algae blooms had a 15 times greater chance of getting ALS. Research by Prof. Mike Parsons, a Florida Gulf Coast University marine biologist, found airborne cyanobacteria toxins a mile from retention ponds and three miles from the Caloosahatchee River. A study of air filters near bodies of water infected with blue-green algae along the Caloosahatchee River taken during the heavy blooms in 2018 by Dr. Larry Brand of the University of Miami Rosenstiel School of Atmospheric and Marine Science is expected soon.

Woods Hole Oceanographic Institution (WHOI) is studying this problem, too, one of many climate-change-related ones.

Figure 1: Cyanobacterial assemblages (A–D) showing the unicellular as well as filamentous Cyanobacteria in the biofilms and morphology of some dominant cyanobacterial cells such as Synechocystis sp. (E), Scytonema sp. (F), Nostoc sp. (G), Gloeocapsa sp. (H), and Gloeocapsopsis sp. (I). Scale bars = 10 μm.

References:

• R. P. Rastogi, D. Madamwar, A. Incharoensakdi, “Sun-screening bioactive compounds mycosporine-like amino acids in naturally occurring cyanobacterial biofilms: Role in photoprotection“, Journal of Applied Microbiology, 2015, 1119, 753-762.. Source of figure above.
• R. P. Rastogi, D. Madamwar, A. Incharoensakdi, “Bloom dynamics of Cyanobacteria and their toxins: Environmental health impacts and mitigation strategies“, Frontiers in Microbiology, 2015, 6, 1254ff.

Quoting from second reference above:

… [C]ultural eutrophication from domestic, industrial, and agricultural wastes as well as global climate change can play a major role in the global expansion of harmful algal blooms and toxin production.

Hat tip to Professor Robert Young of the Program for the Study of Developed Shorelines for the reference.