(CNN) -- A massive molasses spill this week in Honolulu Harbor could lead to an increase in the number of sharks, barracuda and eels as well as bacteria in the area, the Hawaii Department of Health warned.
"While molasses is not harmful to the public directly, the substance is polluting the water, causing fish to die and could lead to an increase in predator species," the health department said in a prepared statement Wednesday.
"The nutrient-rich liquid could also cause unusual growth in marine algae, stimulate an increase in harmful bacteria and trigger other environmental impacts."
Roger White, of Cool Blue Diving, shot video of the mess on the ocean floor, where the heavy liquid settled. "I didn't know so many creatures were down there before, but they're all dead, and they're all laying across the bottom -- hundreds and hundreds, thousands," he told CNN affiliate Hawaii News Now.
Crews from the health department were collecting marine animal carcasses and water samples to monitor the movement and the impact of the molasses plume.
"This is the worst environmental damage to sea life that I have come across, and it's fair to say that this is a biggie, if not the biggest, that we've had to confront in the state of Hawaii," Deputy Director Gary Gill told Hawaii News Now.
Video from CNN affiliate KITV showed the colorful bodies of the wildlife bobbing on the surface of the water as workers scooped them into nets.
"It seemed like they were trying to gasp for air," Sachi Uehara, a resident, told KITV. "There were, I would say, over 50 eels that were up at the surface that we could see."
The health department warned against eating the fish and urged swimmers to stay out of the ocean where the water is brown.
The fish kill began before dawn Monday, when a ship loaded with 1,600 tons of molasses set sail for the West Coast, where its cargo was to be processed.
But a leak in a pipeline to the Matson Navigation ship spewed as many as 1,400 tons -- 233,000 gallons -- of the sticky stuff into the water, the health department said, citing the shipper.
By 8 a.m., the Coast Guard had been notified that Honolulu Harbor's water was discolored; a plume was moving with the tides and currents from the harbor into nearby Keehi Lagoon, where it was expected to dissipate.
Experts said the spill's impact will be long-lasting.
"It's in a bay, so there's not a lot of circulation, so you're not going to have flushing of this water out," biologist David Field told CNN affiliate Hawaii News Now. "So, in this area where the spill occurred, we're going to see the effects probably for a long time."
Field, an assistant professor of marine sciences at Hawaii Pacific University, said the effects of the spill may grow.
"As water does leave this bay area and goes out into the neighboring ocean, we can expect the effects in the long term, in days, weeks, months and probably years," he said.