Many people visit California each year to take in its culture, wine, and natural beauty. Among the lesser-known attractions is a phenomenon referred to as California’s red tide. When this environmental event occurs, the waters of the Pacific along the coast turn red, creating a stunning visual effect and a troubling environmental issue.Also known as algal bloom, the red tide of California is the result of the exponential multiplication of algae that emit Bioluminescence and change the colour of the water. This particular bloom of algae decreases the oxygen levels in the water and releases toxins that depending on the intensity can be harmful to both humans and animals. If you witness a red tide when you travel to California, during the day it may appear that the sun is dissolving into the ocean, or that the ocean has been transformed by a red wave of blood. Find a quiet spot on the sand in the dark of night though, and you're in for some super charged surf. At night the waves turn the algae from red to neon blue. These electrified waters are a dazzling spectacle to witness, easily comparable to the beauty of the Auror Borealis Though beautiful to observe and photograph, California’s red tide presents a danger to the coast. The algae that cause the California red tide, actually travel from long distances and are brought by ships and other sailing vessels, or even storms. These tides were never considered harmful until 1980 when American scientists found that they carried toxins. This could have been caused due to the industrial boom, chemical farming and pollution. A close examination of these toxins did not reveal any information. It is unknown even today as to why these toxins are formed. However harmful these toxins prove to be to humanity, the fish and the krill that live in the ocean remain unaffected by it.Technology has been developed to detect the California red tide and other algal blooms worldwide. Not all red tides are harmful, and so satellite imagery is used to detect red tides and assess the potential environmental impact. Some research suggests that shellfish play a role in carrying the harmful algae and the larger fish that consume the shellfish during a red tide, died. So detecting the phenomenon helps scientists monitor the harmful growth and also warn people against consuming shellfish.Organizations such as Cal-PReEMPT (California Program for Regional Enhanced Monitoring for Psycho-Toxins), and the Environmental Protection Agency, monitor the occurrence of red tide and issue warnings accordingly. Research has linked California’s red tide to the appearance of hundreds of dead seagulls on California’s coast, and scientists continue to assess the causes and impacts of algal bloom.An increase in the incidence of red tides in California, paired with the availability of satellite imagery, has increased the interest in this phenomenon.