A new study conducted by University of Miami researchers provides the first evidence that red tides affect functions of the sensory systems of living organisms. Red tides are blooms of phytoplankton, which are tiny or microscopic algae, in seawater. Along the coastline of West Florida, a phytoplankton known as Karenia brevis produces natural toxins called brevetoxins that can cause massive kills of fishes, birds and marine mammals, including endangered species.
Zhongmin Lu, Seth Tomchik, and Zemin Xu of the University of Miami have now found that a purified version of a K. brevis neurotoxin, brevetoxin-3, causes significant hearing loss in goldfish.
The researchers presented their findings at the 142nd Meeting of the Acoustical Society of America (ASA) this week in Fort Lauderdale.
"Not only does this lend insight into understanding the risks to marine life," said Lu, assistant professor of biology at UM, "but it also enhances our awareness of potential neurotoxic effects on the sensory systems of other vertebrates, including humans."
The researchers injected a sublethal dose of brevetoxin-3 into goldfish and measured their hearing sensitivity using auditory brainstem recording techniques.
The study was funded by a grant from the National Institute of Deafness and Communication Disorders (NIDCD) of the National Institutes of Health (NIH), a pilot project award from the National Institute of Environmental Health Sciences (NIEHS) and UM start-up funds.
"This is an example where our community outreach and education program assisted us in identifying research that we can apply to understanding the human health effects of harmful algal blooms," said Patrick Walsh, Director of the NIEHS Marine and Freshwater Biomedical Sciences Center at UM.
The Center's researchers decided to fund a pilot study on the effects of brevetoxins on the central nervous system when they began receiving reports from people living close to coastal areas affected by red tides saying they were experiencing difficulties with their balance, a function of the inner ear. - By Alexandra Ravinet
Related website:
NIEHS Center at the University of Miami
[Contact: Dr. Zhongmin Lu, Alexandra Ravinet]
08-Dec-2001
