How are red tides harmful to the environment and animals
Red tides are not always connected to the tidal movement of water hence the choice made by scientists to call them algae bloom. The density of these organisms is more than tens of millions of cells per liter of water (Lallanilla 1). The red tides are harmful to fish and other marine animals. The toxins produced by these algae when consumed by the fish becomes harmful to human beings due to saxitoxin. Red tides have been associated with numerous deaths of coastal species of fish, marine mammals, birds and other organisms. An example is the 14 humpback whales that died near Cape Cod, MA in one month as a result of saxitoxin in mackerel that they had consumed. In 1996, 150 Florida manatees died due to effects produced by Karenia brevis.
Both stomach and lung contents in 10% of the endangered animals contained saxitoxins which suggested that the toxins got into their bodies through the food web and direct contact with toxic aerosols when the animals came to the surface to breathe. Between March and April 2003, 107 bottlenose dolphins along the Florida Panhandle were reported dead. These events have proven that red tides produce toxins that can be harmful to other all animals even those higher in the marine food web such: 1. Another effect of toxic dinoflagellate Karenia brevis is the closure of shellfish beds due to the occurrence of NSP and respiratory and skin irritation to humans at the seashore. Fish that die from the toxins produced by the algae bloom are a health hazard as they rot, and birds such as pelican can become intoxicated by eating these fish.
Impacts of Golden Algae, scientifically known as Prymnesium parvum Golden algae are one of the most popular and problematic red tide in America and has caused deaths of numerous fish in Texas since 2001. Prymnesium parvum has been found in 25 lakes and rivers around Texas, with the most toxic blooms occurring around winter months. Fish killed are such as largemouth bass, smallmouth bass, catfish, striped bass, crappie, and rainbow trout. The main species affected in the Gulf of Mexico by the algae bloom are loggerhead, green, and Kemp’s ridley sea turtles. An outbreak of karenia brevis in 2005-2006 off the coast of Florida caused 318 sea turtles stranding, with over 90 % of these sea turtle testing positive for the toxins produced by the karenia algae.
The stomach linings of the turtles suggested that they may have consumed prey that was already contaminated with the toxins. The lungs of some of the sea turtles also suggested that the turtles had inhaled the toxins as they were covered with brevetoxin. Sea turtles come to the surface of the water for 2-3 deep breaths before they go back under water. Some marine animals are not affected by the toxins produced by the algae bloom. These animals are grazers such as fish and krill. However, animals that feed on fish that have eaten the toxic algae are affected by these harmful toxins. When humans consume these toxins produced by red tides, they can suffer from the following diseases: • Paralytic Shellfish Poisoning (PSP)- this disease is caused by toxins produced by Alexandrium species.
• Diarrhetic Shellfish Poisoning (DSP)- this Dinophysis species cause this disease. Red Tide - A Harmful Algal Bloom. March 2015. web. December 2017. Connors, Ian R. West Coast. Limnology and Oceanography (2005): 14. Document. Lallanilla, Marc. What Causes a Red Tide? 11 March 2013.
From $10 to earn access
Only on Studyloop