Here in West Volusia, we hear more about the effects of climate change than we see them. That may soon be changing.

Incidents of blue-green algal blooms along the St. Johns River have been reported far earlier than normal this year — the first confirmed blooms were in early April, nearly three months earlier than in previous years.

Algal blooms block light and absorb oxygen, creating conditions that threaten all aquatic life. They can also pose dangers to humans.

While many of the more dramatic blooms have been identified in areas north and south of this county, as well as on the coastline, Volusia County is not exempt from this threat to Florida’s ecosystem.

In West Volusia, an algal bloom was reported in Lake George on April 10. Reports of diseased fish in Blue Spring in Orange City have been linked by watchdogs to the same cause connected to algal blooms — increased nutrients in our waterways.

On June 6, a bloom was detected in a canal just south of the spring.

Climate change, the gradual warming of the planet driven by human activity, is a huge interconnected web of cause and effect.

When humans put nutrients into the ground, the nutrients leach into our waterways, especially in Florida, where our interconnected aquifer and waterways are inextricably linked.

Even inland, ditches and retention ponds are designed to recharge the aquifer. You don’t have to be near a body of water to have an effect on it.

Nonpoint source pollution — nutrients and other byproducts of human activity that cannot be traced to a single source — is one of the largest, and most difficult to contend with, sources of the nutrients that can produce algal blooms.

Around 22 percent of nitrogen in our groundwater is from urban turfgrass fertilizer — basically, fertilizer applied to lawns — according to the June 2018 Volusia Blue Spring Basin Management Action Plan.

Excess nitrates and phosphorus — two nutrients commonly found in fertilizer — and warm ambient temperature work together to make an environment extremely palatable to various forms of algae.

“What you put in the ground is in the water,” Be Floridian Now Coordinator Megan Martin said. “Nitrate, in particular, is highly mobile in the soil and can easily move between soil particles and into our groundwater, especially when it rains.

“Once in our water bodies, these nutrients can cause harmful algal blooms. This is because nitrates and phosphates are nutrients that promote growth. The sudden growth of algae blocks out light, lowers the water’s oxygen level, turns the water a green or rust color, and leads to fish kills.”

The blooms themselves have deleterious effects not only on the health of the waterway, and all the organisms that live in it, but also on the humans who swim, fish and play.

“Algal blooms are visual symptoms that the river is sick,” St. Johns Riverkeeper Outreach Director Kelly Thompson said.

The death of the algal bloom can produce nerve toxins and liver toxins. The toxins can be released into the air by splashing from boat wake, or people swimming. The blooms themselves can suck up all the oxygen in the water, leading to fish kills.

Algal blooms can be reported through the Florida Department of Environmental Protection at 855-305-3903, or their interactive website, linked below, and the St. Johns Riverkeeper local offices at 117 W. Howry Ave., DeLand, or 407-607-2965.

The St. Johns Riverkeeper also offers water-quality testing kits to volunteers.

The University of Florida Institute of Food and Agricultural Sciences offers free soil testing. They may be reached at 386-822-5778 or at 3100 E. New York Ave., DeLand.