The eruption on Hawaii island has destroyed entire neighborhoods and forever changed the lives of hundreds of people. But have you ever stopped to wonder how it is affecting the ocean and marine life?

The molten magma in the recent eruption first reached the Pacific Ocean off of Kapoho on May 20, 2018.

Since then, it’s covered pristine tide pools, hot springs and beautiful coastal waters.

Frank Sansone a professor of oceanography at UH Manoa has studied the impact lava has on the ocean and nearshore waters for decades. 

“On the shoreline, the differences will be night and day,” Sansone said. “What used to be a lush productive environment with hot pools and animals of all different kinds, it’s going to be either a black sand beach or a cliff.”

Sansone has seen the destruction of coastal waters before with his own eyes diving near the eruption at Kalapana in the 1990s.

“When the lava goes under, it erupts under water. There’s a lot of explosions. That’s from hydrogen gas exploding. If you were diving there, you would feel the sound of these explosions as a slam against your chest,” Sansone said.

Lava emits sulfur dioxide and hydroiodic acid, which changes the acidity in the water.

“A very large change in the acidity and marine organisms would be very sensitive to that and would stay away.”

Sansone said there are also harmful particles where the lava flows into the ocean.

“In the entries, you’d see a big brown plume heading off. Those are little glassy particles, which obviously would cause problems for animals when they’re transferring water through their gills,” Sansone explained.

The good news is that most fish and marine life leave the area. But not everything escapes. The creatures limited to the tide pools are swallowed by the relentless lava flow.

How long will it take for life to return?

Samsone said it could take hundreds of years.

“What we’re going to see are more deep water animals that normally reside along this coast,” Sansone explained as he pointed to a map of Hawaii island and an area far offshore in much deeper water. “We will not see the inshore, the coastal kind of things, that made Kapoho such a special place.”

“If you kept a careful eye, you would see the black sand beaches coming and going maybe they would migrate down the coast,” Sansone said. 

Megumi Chikamoto, a postdoctoral fellow at the International Pacific Research Center, is studying the impact volcanic activity has on the Pacific Ocean. She said in some ways the eruptions can enhance marine life.

“Conditions and mixing ash supplies nutrients to the surface that cause a strong biological productivity in the ocean,” Chikamoto said.

Chikamoto said the ash blocks the sun and causes the ocean temperature to drop creating ideal conditions for growth.