The idea here is we’re going to be making a lot of these
— Matthew Long, Subtidal co-founder/chief scientist
Yellow Buoy Raises Red Flag for Cyanobacteria
A WHOI spinoff launches its first floating early warning system of the season
Click on image to watch short video story.
31 May 2026 – CENTERVILLE, MA – The inflatable pushes off from shore, ferrying its bright yellow passenger to a season of service. We’re at Long Pond in Centerville and the first Harmful Algal Bloom (HAB) buoy launch has begun.
Where do HAB buoys go?
At the end of May, Subtidal launched its first cyanobacteria early warning buoy of 2026. After a four-pond pilot last year the sensor-filled device developed by this spin-off from the Wood Hole Oceanographic Institution (WHOI) has evolved and multiplied.
The buoy bobs not only in Cape Cod and Martha’s Vineyard ponds, but also in fresh water across Massachusetts, and into Connecticut and New Hampshire.
“The idea here is we’re going to be making a lot of these,” said Matthew Long, Subtidal co-founder and chief scientist as well as associate scientist of marine and geochemistry at WHOI.
What does a HAB buoy do?
Long points out the sensor-filled buoy’s features: solar power, warning alert light, an internal stack of internals, and bird guards.
After 3 years of development, the devices have shrunk in size, weight, and price. This year’s model costs about $6000 to sense its liminal environment for the six-month season.
The buoys record, warn and gather data from launch until freeze, serving as both an important real-time alert for pond users and delivering on a science research goal of understanding the dynamics of fresh water and the increasingly common cyanobacteria.
What is cyanobacteria?
“Cyanobacteria have been on earth for three and half billion years. They are the reason we have oxygen to breathe right now,” explains Long.
“When you have a cyanobacteria bloom they can be toxic themselves, but the big problem is when that bloom starts dying and starts degrading, their cell walls break open and then the toxins are released into the water.”
The toxins can be fatal – every year on Cape Cod dogs die from drinking pond water with cyanotoxins. Human children also risk serious illness from the bacteria.
“It’s hard to protect dogs and kids from cyanobacteria blooms and their toxins,” he said.
How does this buoy represent technology transfer?
This little yellow buoy also represents a Cape Cod economic story, showing how intentional technology transfer can move ideas from a lab into scalable solutions. It developed out of WHOI program that connected scientists and entrepreneurs.
But, while companies like Subtidal are born when science meets commerce, but Long is quick to point out that doesn’t mean science gets pushed aside by commerce – for these cyanobacteria early warning systems, the science focuses on building ongoing understanding the dynamics of fresh water ecosystems and the triggers for the algal blooms.
Why does pond monitoring matter?
“Cyanobacteria blooms are becoming more common; they are lasting longer. That has to do with just ongoing excess nutrients coming into our fresh water systems, but also climate change. Our waters are warming and that very specifically favors cyanobacteria,” said Long.
“We do this real time warning system but at the end of season we also do a root cause report,” he added.
“This problem isn’t going away, it’s only going to get worse. And this is the first step at really getting that understanding and knowing what is going on.”
For more information:
Subtidal website – https://www.subtidal.com/
Commonwealth of MA – identifying cyanobacteria scums – https://www.mass.gov/info-details/identifying-cyanobacterial-blooms-and-scums-photographs-of-blooms-and-scums
