All appeared well at the Waiopae tide pools on Thursday following a die-off of marine life earlier in the week.
Dozens of fish, eel and crab — perhaps at least 50 — were reported to have been found dead Tuesday in what has been described as the main lagoon at the popular Kapoho snorkeling area.
A state Department of Health official from Kailua-Kona arrived the next day and found nothing unusual with the water, though oxygen levels were described as being a bit lower than normal in shallow areas. Bacteria levels were normal.
On Thursday, water samples showed oxygen levels back to normal, said Watson Okubo, Health monitoring section supervisor.
No additional dead organisms were seen and the incident has not been considered a threat to public health.
While a cause hasn’t been identified, the introduction of a poison, such as a herbicide or pesticide, has been suggested as a potential contributor.
The tide pools are located adjacent to homes, many of which are on cesspools.
That has long created concerns over potential sewage contamination in the swimming areas.
Okubo said it’s possible that whatever killed the marine organisms could have been flushed from a residence.
Dye testing may be needed to better assess the impact from the cesspools, he said.
Health officials have also heard reports of the water being cloudy, with a greenish color on Tuesday.
That could point to a possible algae bloom, which can suck oxygen out of the water, Okubo said.
The Health official visiting the tide pools on Wednesday did not notice any issues with water clarity, he said.
Ricardo Zepeda of Honolii described the water as being “very murky and cloudy” when he was there on Tuesday.
“It was yellow-green, something I have never seen before,” he said.
Zepeda said the tide was also low and he didn’t stay in the water long enough to see any dead fish.
“I wanted to get out of there,” he said. “It was funky.”