Could Your Day at the Beach be Killing Coral Reefs?
Sunscreen is used widely across the world and promoted as a means to prevent skin cancer. Tourist flock to the beaches and lather up without thinking of the environmental consequences. The make-up of sunscreens is both organic and inorganic UV chemical filters that reflect or absorb UV radiation instead of allowing the skin to absorb it. Inorganic filters, such as titanium dioxide (TiO2), are used for their effectiveness at reflecting UV radiation, their absorption capacities, and their tolerance by human skin to absorb the filter. Sunscreens do not only contain UV filters but also a variety of things such as preservatives, film forming agents, coloring agents, surfactants, chelators, viscosity controllers, and fragrances (Tovar-Sanchez, 2013). While in the water 25% of applied sunscreen washes off the body and into the water within twenty minutes, then after beachgoers leave the water the surface has an iridescent, oily sheen floating atop due to sunscreen’s lipophilic properties (Danovaro, 2008). Due to the lipophilicity of sunscreen and the persistence against biodegrading, chemicals released into the water column have been shown to bioaccumulate within the food chain. Going directly into the water isn’t the sole way to release sunscreen into the oceans. Sunscreen ingredients, such as oxybenzone, are readily absorbed through the skin then flushed or rinsed off in the shower and flow into the ocean. These effects are worsened of there is a lack of sophisticated sewage in regions with a high volume of sunscreen use. Sunscreen agents have the capability of undergoing photo-degradation which results in the transformation into toxic by-products that get released into the water column. The chemicals within common commercial sunscreen have been proved to be detrimental to coral reefs, aquatic life, and the human economy.
The U.S. National Parks service has found that 4,000 to 6,000 tons of sunscreen enter coral reef areas every year from swimmers, divers, snorkelers, and sunny day users. The dissolution of sunscreen within seawater has been shown to release inorganic nutrients that promote the growth of algae, which can inhibit the availability of resources for corals to grow and thrive in a given area (Tovar-Sanchez, 2013). The addition of sunscreen as concentrations as low as 10µL/L caused large amounts of coral mucus within 18-48 hours and within 96 hours resulted in complete bleaching of hard corals (Danovaro, 2008). This addition of sunscreen resulted in a loss of photosynthetic pigments and decreased membrane integrity within zooxanthellae, the partial or total damage of Acropora nubbin, as well as an increased number of viruses within and surrounding the zooxanthellae. Chemicals within typical sunscreen products can cause viruses to replicate within zooxanthellae until the zooxanthellae explode, leaving behind the skeleton of the corals and spilling the virus out into the surrounding waters infecting nearby corals. The zooxanthellae provide the corals with energy and give them their color, and without the zooxanthellae the corals will bleach and eventually die. It has been estimated that 10% of the world’s coral reefs are threatened due to sunscreen-induced bleaching. While bleaching was found to be faster in environments with higher temperatures, Danovaro (2008) found that chemicals such as burylparaben, ethylhexyl-methoxycinnamate, benzophenone-3, octinoxate, 4-methylbenzylidene camphor, and oxybenzone induce bleaching.
Downs (2014) studied the effects of oxybenzone, found in 3,00 bands of commercial sunscreen worldwide, on coral reefs and found that it causes coral bleaching through lowering the temperature at which the corals will bleach, putting them at higher risk to small environmental changes. Oxybenzone is genotoxic, which damages coral DNA and prompts severe and/or lethal deformities of the corals. It has also been shown that oxybenzone acts an endocrine disrupter causing coral larvae to encase itself within its own skeleton at the developmental stage where a skeleton shouldn’t even be present yet. The bleaching effects of oxybenzone are seen in as little as four days. Downs (2014) found that the concentrations of oxybenzone were found to be twelve times higher in the Caribbean and in Hawaii than other coastal regions, and waters surrounding corals exposed to sunscreen had up to 15 times more viruses than corals not exposed. The effects of oxybenzone can be seen at concentrations as low as 62 parts per trillion (Downs 2014). In an interview Downs stated that the effects of sunscreen on corals “is more like [an] on-off [switch], once the viral epidemic is started, it is not a problem of toxicity.” This goes to show that a very small dosage of sunscreen is equally as dangerous as a high dosage. Oxybenzone not only effects the life of coral reefs but also the life of marine animals. Downs (2014) states that oxybenzone hinders embryonic development in sea urchins, causes gender shifts within fish, and causes pro-carcinogenic and mutations activity in mammals.
Another chemical found to effect aquatic life in sunscreen is benzophenone-2, or BP2. BP2 is a pollutant added to water ways through boat waste, municipal and residential septic fields, landfill leachates, and unmanaged cesspits (Downs 2014). The U.S. Environmental Protection Agency considers BP2 to be an “emerging environmental contaminant of concern” due to its role as a mutagen as well as an endocrine distributor. As a mutagen, BP2 increase the rate of damage done to DNA when exposed to sunlight and causes the DNA to exhibit pro-carcinogenic activities. BP2 acting as an endocrine distributor causes birth defects, reproductive disorders, health issues caused by thyroid hormone imbalances, and feminization of male fish.
A third chemical found to effect marine life after exposure to sunscreen is titanium dioxide (TiO2). A significant fraction of nano-TiO2 residues are released from all commercial sunscreens. The usual commercial sunscreen has about 10% of TiO2 nonoparticle within it, and the daily use by users is roughly 1.8 grams a day, which causes a global release of 230 tons a year in a country the size of France (Botta, 2011). Botta’s (2011) research found that 23-56 tons of nano-TiO2 are released into coral reef areas from sunscreen use. TiO2 is so detrimental to marine life because in saltwater conditions the residues will aggregate and settle at the bottom with sediments effecting benthic organisms. Because TiO2 is not water soluble and accumulates in marine life, it has the capacity to continuously form hydrogen peroxide. Many sunscreens form hydrogen peroxide when they interact with UV rays. This can cause issues within the food webs of the ocean as the hydrogen peroxide damages or kills phytoplankton. Many organisms rely on phytoplankton as a base-level food source, therefor if phytoplankton are killed off due to the increased levels of hydrogen peroxide, the impact will be huge and effect all organisms from zooplankton to large marine mammals. The phytoplankton is the basis for all life in many marine ecosystems, and needs to be protected from these damaging effects. Tovar-Sanchez (2013) found that one gram of sunscreen in one liter of saltwater produced 46 times more hydrogen peroxide than saltwater without sunscreen, this effect was shown after just 22 hours of exposure.
McCoshun (2016) also discovered that common metal nanoparticles found in sunscreen can be attributed to toxicity in medaka fish, crustaceans, and marine diatoms. Sunscreen has also led to the enhancement of viral production in seawater through inducing the lytic cycle in prokaryotes with lysogenic infections and well as infections in bacterioplankton. Due to the majority of commercial sunscreen chemicals to be insoluble in water the highest concentrations of sunscreen tend to be at the surface of the water, which effects light availability of photosynthetic organisms. Organisms subjected to sunscreen exposure were found to have a decrease in population growth when compared to groups with no sunscreen exposure (McCoshun, 2016). This presents a risk of population declines in aquatic life due to the effects of sunscreen use. The combination of reactions to chemicals within the sunscreen and the film on the surface of the water contributes to the loss of large amounts of photosynthetic organisms, which further puts high trophic level organisms in dangerous situations such as becoming endangered or extinct. These effects decreases the availability of food and the biodiversity within the oceans and coral reef systems.
This decrease in biodiversity will cause a decline in tourist attractions and therefore a decline in economic activities for regions that rely on coastal tourism. Coral reefs are important both ecologically and economically for activities such as fishing and ecotourism. The National Oceanic and Atmospheric Administration estimated that the economic contribution of coral reefs around the world is roughly $30 billion per year and $100 million just in the United States. This contribution stems from coral reefs sustaining areas for fishing. While beach tourism and the use of sunscreen have a positive correlation, tourism relies heavily on revenue from people coming to see the beautiful and diverse reefs. This attraction of coral reefs creates a push to produce reef sensitive sunscreen, in order to sustain the economy. Coral reefs don’t only provide for a focal point in tourism they also protect beaches from coastal erosion, and allows for a greater capacity of local substance fishing. With more than half of the world population living in coastal areas, and estimates of 75% of the world’s population living in coastal regions within the next 3 decades, it is vital to decrease the rate of coastal erosion (Tovar-Sanchez, 2013).
The reef systems also help to mitigate climate change through acting as a carbon sink and absorbing carbon that would be contributing to rising average global temperatures. Reefs provide for the well-being of most marine life and protect miles of coastline from storm surges. In recent medical studies the use of corals has been considered a key to new medicines for the 21st century. Corals, reef animals, and reef plants are being used to create new cures for issues such as cancer, arthritis bacterial infections, and viruses. The chemical make-up of our sunscreens needs to be reevaluated and the continuation of coral reefs and other aquatic life needs to be taken into account. With sun protection products being the fastest growing products globally, the negative effects will become disastrous in the upcoming years if no steps are taken to change what our sunscreen is made of. Researchers are not urging consumers to stop the use of all sunscreen, but rather be conscious about the products they are buying. According to the National Park Service, sunscreen containing titanium oxide and zinc oxide have not been found to harm reef systems. The use of clothing to cover up is also being advocated to reduce the use and need for sunscreen. Another method of reducing the exposure of toxic sunscreen on corals is by governments to institute “no sunscreen rules” such as Akumal, Mexico has done in order to protect their sea turtles and coral reefs. There is a middle ground to be found between protecting our environment and protect ourselves and that starts with acknowledging the issues and changing our consumption for the better.
References
Céline Botta, Jérôme Labille, Mélanie Auffan, Daniel Borschneck, Hélène Miche, Martiane Cabié, Armand Masion, Jérôme Rose, Jean-Yves Bottero. (2011) TiO2-based nanoparticles released in water from commercialized sunscreens in a life-cycle perspective: Structures and quantities, Environmental Pollution, Volume 159, Issue 6, Pages 1543-1550.
Danovaro, R., Bongiorni, L., Corinaldesi, C., Giovannelli, D., Damiani, E., Astolfi, P., . . . Pusceddu, A. (2008). Sunscreens Cause Coral Bleaching by Promoting Viral Infections. Environmental Health Perspectives, 116(4), 441-447.
Downs, C.A., Kramarsky-Winter, E., Fauth, J.E. et al. (2014) Toxicological effects of the sunscreen UV filter, benzophenone-2, on planulae and in vitro cells of the coral, Stylophora pistillata Ecotoxicology 23: 175
McCoshum, S.M., Schlarb, A.M. & Baum, K.A. (2016) Direct and indirect effects of sunscreen exposure for reef biota Hydrobiologia 776: 139.
Tovar-Sánchez, A., Sánchez-Quiles, D., Basterretxea, G., Benedé, J.,L., Chisvert, A., Salvador, A., Blasco, J. (2013). Sunscreen products as emerging pollutants to coastal waters. PLoS One, 8(6)
Downs (2014) studied the effects of oxybenzone, found in 3,00 bands of commercial sunscreen worldwide, on coral reefs and found that it causes coral bleaching through lowering the temperature at which the corals will bleach, putting them at higher risk to small environmental changes. Oxybenzone is genotoxic, which damages coral DNA and prompts severe and/or lethal deformities of the corals. It has also been shown that oxybenzone acts an endocrine disrupter causing coral larvae to encase itself within its own skeleton at the developmental stage where a skeleton shouldn’t even be present yet. The bleaching effects of oxybenzone are seen in as little as four days. Downs (2014) found that the concentrations of oxybenzone were found to be twelve times higher in the Caribbean and in Hawaii than other coastal regions, and waters surrounding corals exposed to sunscreen had up to 15 times more viruses than corals not exposed. The effects of oxybenzone can be seen at concentrations as low as 62 parts per trillion (Downs 2014). In an interview Downs stated that the effects of sunscreen on corals “is more like [an] on-off [switch], once the viral epidemic is started, it is not a problem of toxicity.” This goes to show that a very small dosage of sunscreen is equally as dangerous as a high dosage. Oxybenzone not only effects the life of coral reefs but also the life of marine animals. Downs (2014) states that oxybenzone hinders embryonic development in sea urchins, causes gender shifts within fish, and causes pro-carcinogenic and mutations activity in mammals.
Another chemical found to effect aquatic life in sunscreen is benzophenone-2, or BP2. BP2 is a pollutant added to water ways through boat waste, municipal and residential septic fields, landfill leachates, and unmanaged cesspits (Downs 2014). The U.S. Environmental Protection Agency considers BP2 to be an “emerging environmental contaminant of concern” due to its role as a mutagen as well as an endocrine distributor. As a mutagen, BP2 increase the rate of damage done to DNA when exposed to sunlight and causes the DNA to exhibit pro-carcinogenic activities. BP2 acting as an endocrine distributor causes birth defects, reproductive disorders, health issues caused by thyroid hormone imbalances, and feminization of male fish.
A third chemical found to effect marine life after exposure to sunscreen is titanium dioxide (TiO2). A significant fraction of nano-TiO2 residues are released from all commercial sunscreens. The usual commercial sunscreen has about 10% of TiO2 nonoparticle within it, and the daily use by users is roughly 1.8 grams a day, which causes a global release of 230 tons a year in a country the size of France (Botta, 2011). Botta’s (2011) research found that 23-56 tons of nano-TiO2 are released into coral reef areas from sunscreen use. TiO2 is so detrimental to marine life because in saltwater conditions the residues will aggregate and settle at the bottom with sediments effecting benthic organisms. Because TiO2 is not water soluble and accumulates in marine life, it has the capacity to continuously form hydrogen peroxide. Many sunscreens form hydrogen peroxide when they interact with UV rays. This can cause issues within the food webs of the ocean as the hydrogen peroxide damages or kills phytoplankton. Many organisms rely on phytoplankton as a base-level food source, therefor if phytoplankton are killed off due to the increased levels of hydrogen peroxide, the impact will be huge and effect all organisms from zooplankton to large marine mammals. The phytoplankton is the basis for all life in many marine ecosystems, and needs to be protected from these damaging effects. Tovar-Sanchez (2013) found that one gram of sunscreen in one liter of saltwater produced 46 times more hydrogen peroxide than saltwater without sunscreen, this effect was shown after just 22 hours of exposure.
McCoshun (2016) also discovered that common metal nanoparticles found in sunscreen can be attributed to toxicity in medaka fish, crustaceans, and marine diatoms. Sunscreen has also led to the enhancement of viral production in seawater through inducing the lytic cycle in prokaryotes with lysogenic infections and well as infections in bacterioplankton. Due to the majority of commercial sunscreen chemicals to be insoluble in water the highest concentrations of sunscreen tend to be at the surface of the water, which effects light availability of photosynthetic organisms. Organisms subjected to sunscreen exposure were found to have a decrease in population growth when compared to groups with no sunscreen exposure (McCoshun, 2016). This presents a risk of population declines in aquatic life due to the effects of sunscreen use. The combination of reactions to chemicals within the sunscreen and the film on the surface of the water contributes to the loss of large amounts of photosynthetic organisms, which further puts high trophic level organisms in dangerous situations such as becoming endangered or extinct. These effects decreases the availability of food and the biodiversity within the oceans and coral reef systems.
This decrease in biodiversity will cause a decline in tourist attractions and therefore a decline in economic activities for regions that rely on coastal tourism. Coral reefs are important both ecologically and economically for activities such as fishing and ecotourism. The National Oceanic and Atmospheric Administration estimated that the economic contribution of coral reefs around the world is roughly $30 billion per year and $100 million just in the United States. This contribution stems from coral reefs sustaining areas for fishing. While beach tourism and the use of sunscreen have a positive correlation, tourism relies heavily on revenue from people coming to see the beautiful and diverse reefs. This attraction of coral reefs creates a push to produce reef sensitive sunscreen, in order to sustain the economy. Coral reefs don’t only provide for a focal point in tourism they also protect beaches from coastal erosion, and allows for a greater capacity of local substance fishing. With more than half of the world population living in coastal areas, and estimates of 75% of the world’s population living in coastal regions within the next 3 decades, it is vital to decrease the rate of coastal erosion (Tovar-Sanchez, 2013).
The reef systems also help to mitigate climate change through acting as a carbon sink and absorbing carbon that would be contributing to rising average global temperatures. Reefs provide for the well-being of most marine life and protect miles of coastline from storm surges. In recent medical studies the use of corals has been considered a key to new medicines for the 21st century. Corals, reef animals, and reef plants are being used to create new cures for issues such as cancer, arthritis bacterial infections, and viruses. The chemical make-up of our sunscreens needs to be reevaluated and the continuation of coral reefs and other aquatic life needs to be taken into account. With sun protection products being the fastest growing products globally, the negative effects will become disastrous in the upcoming years if no steps are taken to change what our sunscreen is made of. Researchers are not urging consumers to stop the use of all sunscreen, but rather be conscious about the products they are buying. According to the National Park Service, sunscreen containing titanium oxide and zinc oxide have not been found to harm reef systems. The use of clothing to cover up is also being advocated to reduce the use and need for sunscreen. Another method of reducing the exposure of toxic sunscreen on corals is by governments to institute “no sunscreen rules” such as Akumal, Mexico has done in order to protect their sea turtles and coral reefs. There is a middle ground to be found between protecting our environment and protect ourselves and that starts with acknowledging the issues and changing our consumption for the better.
References
Céline Botta, Jérôme Labille, Mélanie Auffan, Daniel Borschneck, Hélène Miche, Martiane Cabié, Armand Masion, Jérôme Rose, Jean-Yves Bottero. (2011) TiO2-based nanoparticles released in water from commercialized sunscreens in a life-cycle perspective: Structures and quantities, Environmental Pollution, Volume 159, Issue 6, Pages 1543-1550.
Danovaro, R., Bongiorni, L., Corinaldesi, C., Giovannelli, D., Damiani, E., Astolfi, P., . . . Pusceddu, A. (2008). Sunscreens Cause Coral Bleaching by Promoting Viral Infections. Environmental Health Perspectives, 116(4), 441-447.
Downs, C.A., Kramarsky-Winter, E., Fauth, J.E. et al. (2014) Toxicological effects of the sunscreen UV filter, benzophenone-2, on planulae and in vitro cells of the coral, Stylophora pistillata Ecotoxicology 23: 175
McCoshum, S.M., Schlarb, A.M. & Baum, K.A. (2016) Direct and indirect effects of sunscreen exposure for reef biota Hydrobiologia 776: 139.
Tovar-Sánchez, A., Sánchez-Quiles, D., Basterretxea, G., Benedé, J.,L., Chisvert, A., Salvador, A., Blasco, J. (2013). Sunscreen products as emerging pollutants to coastal waters. PLoS One, 8(6)
