California contains a multitude of freshwater lakes and trails that are available to the public for recreational activities. Recently, some of the popular reservoirs and lakes in nearby areas, such as Alameda County, have become infected with high quantities of harmful algal bloom.
Algal bloom refers to a rapid increase in microscopic algae and it usually appears in thick mats on top of bodies of water. It is caused by environmental factors like changes in sunlight exposure, disturbances in temperature and a disruption in the pH balance.
“You can have an algal bloom that is harmless and won’t cause any problems, or you can have harmful algal blooms, which are when certain types of algae bloom release toxins into the water,” said environmental science teacher Greg Moretti. “They can make people very sick. It can cause respiratory problems and even death when people are exposed to that algae.”
In Alameda county, lakes such as Lake Del Valle, Lake Anza and Lake Chabot are currently advised as dangerous or cautionary in accordance with algal bloom levels. These lakes all exist within the San Francisco-Oakland-Hayward area near the California coast, where the population of algal blooms is spiking. The lakes are accessible via hiking trails, and some of them, such as Lake Del Valle and Lake Anza, serve as recreational swimming reservoirs and are visited by families and nature enthusiasts alike.
There is some uncertainty as to what is causing this spike of algal bloom in California, but some attribute it to climate change.
“Warm water temperatures tend to increase the numbers of harmful algal blooms, so there may be a connection with climate change,” Moretti said.
The spike of harmful algal bloom in California may also be credited to the long-lasting drought conditions that are prevalent within the state.
“[Algal blooms] have become more frequent as a result of environmental changes caused by humans, so I think it is important to educate ourselves about different activities that … cause [them]”
“These bacteria really like it when there are drought conditions,” Morretti said. “When there’s a drought, typically bodies of water get smaller and warmer. [It] gets stagnant [because] there’s no freshwater flowing in. … [These] types of conditions tend to trigger those harmful algal blooms.”
Algal blooms reduce wildlife’s ability to find food and the pollution they cause can harm animals and other plants that rely on these lakes for survival.
“Algal blooms can cover water and keep the sunlight from reaching species that live at the bottom,” said sophomore Emma Samayoa. “That can be very harmful to ecosystems. Even though algal blooms are a natural occurrence, they’ve become more frequent as a result of environmental changes caused by humans, so I think it is important to educate ourselves about different activities that can cause algal blooms and how to help prevent them.”
For students at Aragon who enjoy the outdoors, like Samayoa, the rise of harmful algal blooms in nearby lakes can be detrimental to the enjoyment of their hobbies.
“On one of my favorite hiking trails, [the Bay Trail on the Foster City lagoon], you can see the algal bloom, and sometimes you can even see the warning signs,” Samayoa said. “I really like hiking, so it is upsetting to see all of the different health concerns.”
Sophomore Sacha Perslon is another environmentally conscious student who enjoys hiking and the outdoors.
“I grew up going hiking, backpacking with my family and going to the beach, so being outdoors is a big part of my life,” Perlson said. “I want to help the environment when I grow up because of the influence it’s had on me.”
On a trip to Florida, Perlson was personally affected by algal blooms of the saltwater variety, a harmful sea bloom known as the red tide.
“I got super sick and I could only stay outside for about five minutes,” Perlson said. “We figured out that it was because of algal bloom that had formed in the ocean. It made being in Florida unbearable and it really affected my health. Every time I went outside, I could barely breathe. I also had a terrible cough.”
Ultimately, harmful algal bloom reduces the usability of infected waters, damaging both the environment and those that enjoy hiking. Harmful algal blooms can be slowed by decreasing waste and factory runoff that may affect these bodies of water.
