When the right mix of heat and bacteria clashes with other natural and man-made factors, hazardous and unsightly conditions can arise in water areas across the country.
At times, the combination can prove deadly to humans who come into contact with the infected water. In other cases, mass quantities of running water can be marked too dangerous to use as seen in Lake Erie's outbreak of harmful algal blooms that gripped the nation's attention.
With summer's increasing temperatures and the spike in swimmers along beaches and lakes throughout the country, lurking dangers hidden in the waters can make a favorite seasonal pastime risky.
A vast outbreak of malignant algae created chaos for the city of Toledo, Ohio, in early August as parts of Lake Erie became infected and all city water was deemed unsafe.
The blooms were a malignant type of cyanobacteria that crowd water areas, typically late in the summer to early fall for the Great Lakes region. As Toledo's water supply sources from the impacted area, residents were not to use their running water supplies for nearly four full days.
Local water supply stations were set up throughout the city where residents could obtain bottled water. Unlike other water contamination issues, boiling the water would only enhance the hazardous algae due to the organism's composition.
Higher temperatures can be a contributing factor to an increase in blooms, according to Professor and Director at the Graham Sustainability Institute at the University of Michigan Don Scavia. However, he explained that the key factor is the amount of phosphorus flowing into the lakes from agricultural watersheds.
Water was deemed unsafe to use for all purposes for nearly 400,000 people.
A flesh-eating bacteria that thrives in warm seas killed one swimmer at a Sarasota County beach in late July as water surface temperatures rose across the region.
According to the Center for Disease Control, the bacteria prospers in isolated areas of warm sea waters. Risks are highest during summer months due to the peak temperatures.
No specific date or beach was given, but the bacteria, formally known as Vibrio vulnificus, has proven deadly across various area beaches.
This was the second reported case for the county in July alone. The other case resulted in sickness. The county's Department of Health said that both individuals were middle-aged and had compromising medical conditions. In 2013, the state of Florida reported 41 cases, 11 of which resulted in death. This is the 11th reported case for 2014.
A heat-loving, brain-eating amoeba, known as Naegleria fowleri, claimed the life of a 9-year-old Kansas girl after she contracted an infection brought on by the deadly amoeba in early July.
Officials could not determine which body of water inflicted the amoeba on the young girl but stated there were several potential exposures to fresh water.
Naegleria fowleri is a heat-loving amoeba commonly found around the world in warm, fresh water bodies such as lakes, rivers and hot springs, as well as soil, according to the Centers for Disease Control and Prevention. The amoeba is not found in salt water.
When ingested, the amoeba can cause an infection known as Primary Amebic Meningoencephalitis (PAM). Infection-causing PAM is extremely rare, according to a press release from the Kansas Department of Health. From 1962 to 2013, there have been 132 cases reported in the U.S., with 34 cases coming between 2004 and 2013.
Cases of Naegleria fowleri are more common in July, August and September when there is prolonged heat and thus higher water temperatures and lower water levels. Infection typically occurs after the amoeba enters the body through the nose and travels to the brain when a person is swimming underwater.
Low water may have played a role as Kansas is suffering from drought conditions. Dr. Jennifer Cope, medical epidemiologist at the CDC, said when examining where infections may have originated, they find that infections occur where water levels are low or where there are drought conditions or after a heat wave.
A type of potentially toxic algae known as "red tide" blanketed an area roughly the size of Connecticut in the northeastern part of the Gulf of Mexico in late July.
The Florida Fish and Wildlife Conservation Commission released a report on July 25, 2014, confirming a large-scale fish kill in the area. Since then, more fish have died as a result of the toxic, but naturally occurring, algae, formally called Karenia brevis.
Though outbreaks of this kind of algae are not uncommon, surface water temperatures had been warmer in the area over the past week, according to AccuWeather.com Expert Meteorologist Dan Kottlowski. Warmer waters can play an instigator in the algae's growth.
Given the nickname 'red tide' due to the red hue some blooms can give to the water, the harmful algae blooms can cause health concerns for humans. Some blooms will not create hazardous swimming conditions, but severe cases can create havoc.
Respiratory irritation in humans can occur when a bloom of the red tide organism is present along the coast and winds blow the aerosol it produces on shore, according to the National Weather Service.
This outbreak proved unique by the mass amounts of fish that died as a result of the impacted waters. The FWC detailed thousands of fish that were found dead in a later report.
5. Uptick in Heat Prompts Volunteers to Clear 13,500 Pounds of Dead Fish From Southern California Marina
A stretch of above-normal warmth in Southern California created an unwelcome odor as thousands of dead fish covered the surface of marina waters over the weekend leading up to Memorial Day.
Volunteers were left to clear a marine basin which had become blanketed by dead fish piling up atop the water. The California Department of Fish and Wildlife said that approximately 300 bags of fish, each weighing 45 pounds, were recovered by Los Angeles County Beaches and Harbors. Most of the affected fish were anchovies.
The area experienced record-breaking temperatures, including a high of 102 degrees Fahrenheit in downtown Los Angeles on Thursday, May 15.
When temperatures rise, oxygen levels decrease in the water due to the decay of algal blooms. Without enough oxygen, fish and other sea organisms cannot survive. According to the Centers for Disease Control, algal blooms can also block necessary sunlight to the fish along with depleting oxygen.