Rising saltwater is threatening marine ecosystems

Increased salinity in oceans and coastal areas has potentially devastating effects, a new UNF study concludes.

Increased salinity in oceans and coastal areas — the result of climate change and poor land use — has potentially devastating effects on coastal and nearby ecosystems, a new study concludes.

Climate change and man-made intrusions can lead to extreme flooding and drought. As sea levels rise, they push saltwater into coastal and low-lying areas, damaging seagrass beds, harming the shrimping and fishing industries and changing recreational environments, according to the study from the University of North Florida.

“These habitats are subject to change," said Cliff Ross, one of the researchers on the study. "So as the salinity levels change, that's going to have an impact on the ecosystem and may cause certain habitats like seagrass beds or other type of ecological environments, it may cause them to shift into something else or perhaps even die off.”

The St. Johns River is not immune to increases in salinity, or salt content. According to the 2019 State of the River report, salinity levels were increasing in the St. Johns River and its tributaries due to sea level rise and river dredging, causing concerns that continue today.

Lisa Rinaman, the St. Johns Riverkeeper, says more and more saltwater is getting further upstream, leading to threats further inland.

“We're seeing saltwater increases all the way south of the Buckman Bridge," Rinaman said. "And we're seeing barnacles in areas we haven't seen it before. We're seeing jellyfish in areas we haven't seen before."