Molasses Kills Thousands (of Sea Creatures) in Hawaii

Written by Chris Tackett

On Monday, a molasses pipeline (yes, that’s a thing!) leaked 1,400 tons — 233,000 gallons — of molasses into Hawaii’s Honolulu Harbor, and it has turned into a killer mess with no quick solution.

I know what you’re thinking: “A molasses spill? How bad could it be? Just make a bunch of biscuits!”

Well, let’s get the “sticky situation” and “sweet sassy molassy” puns out of the way, because as silly as a molasses spill may sound, this is unfortunately turning into one of Hawaii’s worst environmental disasters.

Thousands of fish, crabs, turtles, eels and other aquatic life are dead, and more are expected to die as the plume of molasses is slowly oozing its way from the harbor and out to sea.

The Associated Press reports on the extent of the damage:

The brown, sugary substance spilled Monday from a pipe used to load molasses from storage tanks to ships sailing to California. The shipping company, Matson Navigation Co., repaired the hole and the pipe stopped leaking Tuesday morning, spokesman Jeff Hull said.

As much as 233,000 gallons of molasses leaked into the harbor, Matson said. That’s equivalent to what would fill about seven rail cars or about one-third of an Olympic-sized swimming pool.

The fish are dying because the high concentration of molasses is making it difficult for them to breathe, said department spokeswoman Janice Okubo. Television footage shows some fish sticking their mouths out of the water.

Making it even worse, the dead fish may be attracting sharks and barracuda to the area, leading officials to warn people not to dive near the site of the spill.

What makes molasses so deadly to aquatic life is how it behaves in the water. Reporters at Hawaii News Now used a jar to demonstrate:

We did an experiment to see why molasses is so hazardous to fish. When we poured store bought Molasses into a vase of water we collected from Keehi Lagoon, the concentrated sugary substance went straight to the bottom.

Unlike an oil spill, which can be cleaned by skimming the surface, the molasses quickly disperses to the deepest points. “It’s sucking up all the oxygen” explained Gulko. “There’s no oxygen at depth so the animals that need it can’t get it and are suffocating.”

Quick aside: Molasses behaves similar to tar sands oil

This is, essentially, the same way tar sands oil or diluted bitumen behaves in water. Because the tar sands are so thick, they are diluted with a cocktail of toxic chemicals, which allows them to flow through a pipeline. However, when a spill occurs, the diluents evaporate into the air, leaving behind the thick, heavy and very sticky bitumen, which sinks to the bottom and is not easily skimmed off the top of the water. This is what makes tar sands spills, such as those that have occurred in Mayflower, Arkansas, and Kalamazoo River, Michigan, so difficult to clean and why there is such fierce opposition to transport pipelines, such as Keystone XL.

Back to the molasses spill, you can get a sense of the scale of this spill from this aerial video at Hawaii Now News:

Hawaii News Now – KGMB and KHNL

Because of the consistency of molasses, officials think there may be negative effects for weeks, months and even years to come.

In 1919, Boston was the site of another massive molasses spill, the Boston Molasses Disaster, during which “a large molasses storage tank burst, and a wave of molasses rushed through the streets at an estimated 35 mph, killing 21 and injuring 150.”

Thankfully no humans were killed in Honolulu’s Molasses Disaster, but sadly the death toll of aquatic life will likely reach into the tens of thousands.

This post was originally published in TreeHugger

Photo Credit: Hawaii News Now


Jim Ven
Jim Venabout a year ago

thanks for the article.

Carrie-Anne Brown

sad news but thanks for sharing

Katherine Wright
Katherine Wright3 years ago

Once again the other species on this planet are paying for OUR sins. When is this going to stop? I agree with another poster.....suffocation must be a horrid way to die.

This makes me incredibly sad and angry. And I wonder why I continue to loathe some/many people.

Melania Padilla
Melania Padilla3 years ago


Donna Ferguson
Donna F.3 years ago

another truly tragic environmental report. when is the tipping point going to come, the unrecoverable tipping point? it seems hopeless

Lynnl C.
Lyn n C.3 years ago


Lori Ann Hone
Lori Hone3 years ago

Very sad

'Great White' Earth & Bei
'Great White' 3 years ago

This is so Frustratingly STUPID on our species' part, this stuff is horrible for us, our grandparents loved this BLANKING BLANK and yet, now it spills and kills our species!

Helen Krummenacker

What a shame, the environment there is so unique.

Yvette T.
Past Member 3 years ago

Suffocation is a horrible way to die. Why must humans be responsible for so much death while visiting Mother Earth?