The Hidden Harm of Shark Finning

UNIVERSITY OF MIAMI RJ. DUNLAP MARINE THE HIDDEN HARM of SHARK FINNING CONSERVATION PROGRAM Shark finning is a profitable yet destructive industry, in which the fins of up to 73 million sharks end up in the shark fin trade each year. Shark fins are a highly valued commodity for their use in health supplements and shark fin soup. However, researchers at the University of Miami have discovered that shark finning may have devastating impacts for both sharks and humans alike. A recent study has shown that shark cartilage contains a neurotoxin that has been linked with Alzheimer's Disease and Lou Gehrig's Disease (ALS), putting shark fin consumers at elevated risk for developing neurodegenerative diseases. The Journey of a Neurotoxin A diverse group of small marine animals feed on cyanobacteria. Many fish and crustaceans have been High concentrations of the neurotoxin BMAA (beta-N-Methylamino-L-alanine) have been detected in fin cartilage samples collected from seven species of sharks off the coast of Florida. Originally produced by bacteria, BMAA bioaccumulates through the food chain, and can be toxic to humans. Cyanobacteria, an aquatic bacteria at the base of the marine food web, are found in most marine and freshwater habitats. When conditions are optimal, they reproduce rapidly, creating visible surface blooms. Most types of cyanobacteria naturally produce BMAA as a byproduct of metabolism. found to have high concentrations of BMAA, especially pink shrimp and blue crabs in South Florida. Shark fin soup, an Asian delicacy, often sells for $100 per bowl, making it one of the world's most expensive fishery products. Shark fin cartilage is also sold as supplements that claim to prevent cancer and joint problems, although there is no scientific evidence supporting this. Sharks are long-lived apex predators, accumulating high concentrations of toxins, such as mercury and BMAA. As highly migratory fish, sharks likely encounter active cyanobacterial blooms, feeding on BMAA-containing fish and crustaceans. Neuroscientist Dr. D. Mash found that brain samples from people who died of Alzheimer's or Lou Gehrig's disease (ALS) had elevated levels of BMAA. WHAT IS ALZHEIMER'S DISEASE? THE INTERNATIONAL FIN TRADE AVERAGE BMAA (ng/mg) in SHARK FINS in S. FLORIDA Projected Increase in the Number of People (In Millions) With AD 120 Alzheimer's Disease (AD) is a form of dementia that gradually worsens with time, affecting memory, cognition, and behavior. It is estimated that by 2050 one in 85 people worldwide will be living with the disease. One pound of shark fins can sell for as much as $880, which makes the shark fin trade a multibilion dollar international industry with 145 countries participating. Researchers at the University of Miami analyzed cartilage samples collected from 29 sharks from the South Florida area. They detected high levels of BMAA in all seven species that were tested. 100 1663 80 WHAT IS ALS? 60 1028 ALS affects motor neurons, the longest cells in the body. Although mental capabilities stay intact, ALS paralyzes patients, and most die within three years when they can no longer breathe or swallow. In about 10% of cases, ALS is caused by a genetic defect. In the remaining cases, the cause is unknown. 929 40 592 Spain is one of the lkargest exporters of shark fins, followed by Singapore, Taiwan, Indonesia, 336 268 20 2010 2020 2030 2040 2050 79 In 2008, nearly 10,000,000 kg of shark fins were imported to Hong Kong. the world's largest market for fins. Blacknose Great Bornethead Blackfp Lemon Bull Nurse and the United States. Hammerhead Read the full article: Mondo K, Hammerschlag N, Basile M, Pablo J, Banack SA, Mash DC. 2012. Cyanobacterial Neurotoxin B-N-Methylamino-L-alanine (BMAA) in Shark Fins, Marine Drugs, 10(2), 509-520; doi:10.3390/md 10020509t