Red Tide

     It is important for all of us to be aware of what is happening in our oceans. Algal blooms, commonly referred to as red tides, present problems worldwide. Although there is practically no solution to the algal blooms, we all must take the safety precautions necessary to stay alive and healthy. 

Effects on Fish

     The algae present in the ocean sometimes can grow and reproduce rapidly. This causes toxins to be released in the water, and can be devastating to fish populations. Also, large algae populations decrease oxygen levels in the water, which can be harmful to fish too. Red tides mainly effect shellfish, as they filter water through their bodies and feed off of the toxic algae. 

Effects on Humans

     Sometimes, the fish may be intoxicated enough to be harmful to humans, but not enough to kill the fish in the first place. Human illnesses via consumption of seafood contaminated by toxic algae include: amnesic shellfish poisoning, ciguatera fish poisoning, diarrhetic shellfish poisoning, neurotoxic shellfish poisoning, and paralytic shellfish poisoning. The symptoms of these sicknesses are usually nausea, vomiting, diarrhea, fever, and/or respiratory malfunctions. Some illnesses may even result in death.

Cause of Red Tides

     It is unknown exactly what is the cause of red tides. They can occur naturally or unnaturally. There are many re-occurring red tides off the coast of France. This is a result of the many years of fertilizer dumping. These fertilizers are what cause the algae to  grow so rapidly.

Effects of Red Tides

     The production of neurotoxins which cause mass mortalities in fish, seabirds, and marine mammals disrupt the ocean ecosystem dramatically. When massive populations of marine animals die, the depletion of food sources can cause irreversible damage to human life. Mechanical damage to other organisms, such as disruption of epithelial gill tissues in fish, result in asphyxiationoxygen depletion of the water column (hypoxia or anoxia) from cellular respiration and bacterial degradation.

     So, it is important for all of us to pay attention to the warnings given to us. We need to be aware of what we are eating and where it came from. 

http://www.whoi.edu/science/B/redtide/illness/illness.html


http://en.wikipedia.org/wiki/Algal_bloom


http://www.eoearth.org/article/Red_tide?topic=49559