By Amanda Gonzalez Garcia
A mass of fish was found dead in Biscayne Bay on Aug. 10, leaving South Floridians concerned about what environmental conditions could have been the cause. City of Miami Mayor Francis Suarez deemed this as an “environmental disaster” and called for action.
Unfortunately, incidents like this are not uncommon, according to Dr. Michael Robinson, an associate professor in the biology department at Barry. However, causes can vary depending on the location where these incidents occur.
According to Channel 7 News, Miami Waterkeeper, an environmental activist organization which aims to educate locals on the importance of clean water, confirmed nutrient pollution as one cause of the fish kill, which Dr. Robinson notes can lead to low oxygen.
“Typically, with terrestrial run-off comes things like fertilizers. The fertilizers then can cause a lot of algae to grow very rapidly,” he said.
The rapid growth of algae, or an algal bloom, can cloud the water and prevent photosynthesis, according to Dr. Robinson. Consequently, the algae dies and decomposes, leaving the bacteria to use up all of the oxygen. This creates low-oxygen areas, like dead zones.
According to Dr. Robinson, dead zones have become more common over the last 30 years possibly due to human activity.
“Seawater has less oxygen in it than air and as water heats up, the amount of dissolved oxygen drops further,” said Dr. Robinson. “In warmer water, the oxygen levels can drop so much that there isn’t enough for fish to breathe and they suffocate.”
Dr. Robinson notes that this is a problem in Biscayne Bay due to human development, which has changed the water flow. Factory production, human waste, uncontrolled sewage, and trash disposal are some of the factors contributing to this change.
“If the water does not move as much as it once did, the warm water can sit in one spot, heat up and there is no cooler water with more oxygen, like from offshore, that can come in and replace it,” said Dr. Robinson.
Dr. Robinson believes the way to prevent an incident like this from reoccurring is by reducing our carbon emission by driving less, using less plastic, and eating food provided by local markets.
In addition, those who are passionate about the environment should attempt to contact their local officials and encourage them to tackle climate change. Local politicians can reduce the use of fertilizers on land, redirect run-off from rainwater, and repair the sewage system.
Another way to get involved is by joining local environmental activist groups, like Miami Waterkeeper. Other groups include The Audubon Society, a national nonprofit that promotes the protection of “land, water and wildlife,” and the Natural Resources Defense Council, an international nonprofit which aims to guard the Earth’s clean air and water.
These organizations aim to emphasize that when our ecosystems fail, so do we.