Red Algal Blooms
Coloring the Tides
Raymond A Martin
College of Central Florida

Abstract
There are large, toxic blooms of dinoflagellates that leave a red coloration in the water. This rouge discoloring has become known as a red tide. Red tides have many damaging effects on the coastal environment and the ecosystem of the seas. They occur naturally as far north as southern Alaska to date. This paper will discuss what a red tide is and some of its causes. It will also explore the environmental impacts as well as health risks associated with these large toxic blooms. Next, we’ll look at the economic effect and the sociological impact of a red tide. Lastly, we can examine what to do to protect yourself from its harmful effects.

Red Tide/Red Algae Effects

What is Red Tide? Harmful algal blooms, or HABs, occur when colonies of algae—simple plants that live in the sea and freshwater—grow out of control while producing toxic or harmful effects on people, fish, shellfish, marine mammals, and birds. The human illnesses caused by HABs, though rare, can be debilitating or even fatal.
While many people call these blooms 'red tides,' scientists prefer the term harmful algal bloom. (NOAA 2012) Algal blooms, during which algae become so numerous that they discolor the coastal waters, visibly seen as reddish-brown. The algal bloom may also deplete oxygen in the waters and/or release toxins that may cause illness in humans and other animals. Species in the United States that release these harmful toxins include: * Alexandrium fundyense - found along the Atlantic coast from the Canadian Maritimes to southern New England * Alexandrium catenella - found along the Pacific coast from California to Alaska * Karenia brevis - found in the Gulf of Mexico along the west coast of Florida (Borkman 2013) Causes:
Red Tides are caused by an extremely rapid growth and accumulation of certain microscopic algae, predominantly dinoflagellates, in coastal waters. Some species of dinoflagellates produce toxins that are among the most potent known to man. That means not all of it is poisonous. The events leading to this phenomenon include warm ocean surface temperatures, low salinity, high nutrient content, calm seas, and rain followed by sunny days during the summer months (NOAA). In addition, algae related to red tide can spread or be carried long distances by winds, currents, storms, or ships. This can affect us in several different ways. Environmentally, economically, our health if exposed or consumed, the quality of life.
Environmental
The same harmful toxins that cause respiratory irritation in humans can also cause mortalities in various marine organisms. In addition to killing many fish and contaminating shellfish, K. brevis blooms can kill marine animals including dolphins and endangered manatees. A red tide in 1996 was responsible for the death of nearly 10 % of Florida’s manatee population and 162 dolphins in Mexico. The extremely large red tide bloom of 2005 resulted in an extensive hypoxic zone off the coast of Southwest Florida. (Flewelling et al. 2013). Within this hypoxic zone, there was a significant die-off of benthic or bottom-dwelling organisms.
Health Issues

No need to worry about shopping or going out to eat, because commercially caught seafood (including seafood at local restaurants and grocery stores) is safe to eat because it is closely monitored for K. Brevistoxins. The State of Florida quickly closes shellfish beds in red tide areas and will not re-open them until shellfish are safe to eat. (Department of Aquaculture 2011). For recreationally caught seafood, it is important to follow a few guidelines. Finfish are safe to eat if they are caught live and filleted. Crabs and shrimp are also okay to eat because the toxins are not absorbed into edible tissues of these animals. It is not safe to eat clams, mussels and oysters from red tide areas because they are filter-feeders and the toxins are absorbed into their tissues. Keep in mind, cooking does not destroy red tide toxins. Do not ever eat distressed or dead animals regardless of whether red tide is in the area. Consumption of shellfish that are contaminated by K. brevistoxins can cause Neurotoxic Shellfish Poisoning (NSP). NSP symptoms usually appear within a couple of hours of eating contaminated shellfish and they last for a few days. Symptoms can include: gastro-intestinal distress, reversal of hot and cold sensations, headache, chills and generalized muscle weakness. Red tide algae make potent natural toxins. It is unknown why these toxins are created, but some can be hazardous to larger organisms through the processes of biomagnification and bioaccumulation. Grazers such as fish and krill are unaffected by the toxins, so as they eat the algae the toxins are concentrated and accumulate to a level that is poisonous to the organisms that feed on them. Large fish kills and several mammalian diseases and deaths have been attributed to consumption of shellfish during red tide algal blooms. The diseases that may affect humans include: * Paralytic Shellfish Poisoning (PSP) - This disease is caused by the production of saxitoxin by the Alexandrium species. It is common along the Atlantic and Pacific coasts in the US and Canada. Poisoning occurs when one ingests shellfish contaminated with PSP toxins causing disruption of nerve function and paralysis. Extreme cases may result in death by asphyxiation by respiratory paralysis. * Diarrhetic Shellfish Poisoning (DSP) - This disease is caused by the Dinophysis species. It generally occurs in Japan and Europe, but it has also been found in other countries such as Canada, the US, Chile, New Zealand, and Thailand. Symptoms of DSP include diarrhea, nausea, vomiting, abdominal pain, and cramps. DSP is generally not lethal. * Amnesic Shellfish Poisoning (ASP) - This disease, which has been found along the eastern Canadian coast, is caused by domoic acid producing planktonic and benthic algae, including Pseudo-nitzschia pungens forma. Pseudo-nitzschia multiseries and Amphora coffaeformis. It can also be found in soft shell clams and blue mussels infected by Pseudo-nitzschia delicatissima. Gastric and neurological symptoms include dizziness, disorientation and memory loss. (CDC 2005).

Economic Impact
This causes millions of dollars in lost revenue to Florida communities, hotels, restaurants and water based tourism attractions like fishing and boating. Coastal communities that rely on tourism lose millions of dollars when dead fish wash up on beaches or beachgoers experience eye and respiratory irritation, and shellfish-harvesting businesses lose income when shellfish beds are closed. A study of three red tide blooms that occurred in the 1970s and 1980s estimated losses from each to be between $15 million and $25 million (FFWCC). They cannot accurately get down to the exact dollar as this is such a staggering event.

Quality of Life
The people living in and around affected areas can undergo a disruption of social relationships and cultural practices tied to coastal resources. It affects beach experiences, water recreation and fishing activities for tourists and locals alike. Current Red Tide status map

Preventative Measures
NOAA recently was funded to explore what role nutrients play, both natural and manmade in the development and duration of red tide blooms. This team has a combined one hundred twenty-five years of K. brevis research experience and identifying alternatives. They will be working with the state of Florida to continue red tide monitoring that is already in place. They will increase use of new technologies such as the water quality detectors with twenty-four hour a day web monitoring capabilities. Also, there is the Red Tide Control and Mitigation program that was established in 2007 by START, Wildlife Research Institute and Florida Fish and Wildlife Commissions. This program funded twelve studies between 2007 and 2009, addressing several topics.

Conclusion
These toxic algal blooms deplete the oxygen and discolor the seas in warm coastal waters as far north as Alaska. There are three species that have been observed locally and are some of the strongest toxins known to man. They contaminate shellfish and kill marine mammals at an alarming rate. Not only would eating contaminated shellfish cause illness, possibly death, but so is the case with inhaling the air in affected areas. It costs millions in lost tourism, medical care and to fishing communities alike. One should be informed of red tide blooms and local weather patterns before venturing to the beach or out on the water and take proper precautions.

Works Cited
"What Is a Red Tide?" National Oceanic and Atmospheric Administration. 3 Sept. 2014. Web. 20 Apr. 2015.
Borkman, Davd. "Recurrent Vernal Presence of the Toxic Alexandrium Tamarense/
Alexandrium Fundyense (Dinoflagellata) Species Complex in Narragansett Bay, USA. Academia.edu. 18 Sept. 2013. Web. 22 Apr. 2015.
Flewelling, Leanne. "Seventh Symposium on Harmful Algae in the U.S. ." Florida Fish and Wildlife Conservation Commission. Sarasota Ballroom, Sarasota. 27 Oct. 2013. Keynote Speech.
"About Florida Red Tides." Florida Fish and Wildlife Conservation Commission. 1 June 1999. Web. 16 Apr. 2015.
"Division of Aquaculture." Florida Department of Agriculture and Consumer Services. Web. 9 Jan. 2013. Web. 21 Apr. 2015.
Centers for Disease Control and Prevention. Centers for Disease Control and Prevention, Oct. 2005. Web. 26 Apr. 2015.