The Gulf of Maine spent summer 2025 looking like an expensive bathroom had been poured into the Atlantic, after a vast bloom of coccolithophores turned its waters vivid blue and green. The microscopic organisms insist this is an ecological event, not a mood board.
NASA’s PACE satellite captured the display on 21 June, showing one of the largest blooms of its kind seen in the gulf in recent years. The ocean was then subjected to the familiar human response to natural beauty: somebody immediately asked who approved the colour scheme.
Coccolithophores are tiny phytoplankton covered in reflective plates of calcium carbonate. They make seawater appear milky blue, which is an impressive achievement for organisms that could lose a fight with a crumb. Their work also supports the marine food web, linking an apparently decorative surface to fish, shellfish and the fisheries that depend on them.
At the Marine Paint Department, Dr Lorna Tidepool studied the satellite image and called the bloom “a triumph of scale”. This is an invented assessment from a fictional department, but it captures the contradiction. Human beings have spent centuries making large things ugly, then reacted with astonishment when microscopic life accidentally produced something tasteful.
Coccolithophore blooms became less common in Gulf of Maine waters from around 2010, although scientists have observed signs of a rebound in recent years. Researchers are still examining how changing water conditions relate to shifts in the gulf’s plankton communities. The organisms have therefore achieved what few public bodies can manage: they have caused a major visual event while refusing to publish a confident strategy document.
PACE’s Ocean Color Instrument can see ocean colour in greater detail than earlier satellites, helping scientists distinguish groups of phytoplankton. Chief Swirl Officer Nobby Kelp said the technology was unnecessary. “We were already visible from space,” he said, in another fictional remark. “The satellite has simply arrived late and claimed it was monitoring us.”
Scientists planned to compare the satellite observations with samples collected at sea, because even a spectacular image needs checking against reality. The bloom has been advised to remain calm during the validation process and not launch a podcast about being misunderstood.
By the time researchers finish explaining the ecosystem, the Gulf of Maine may have moved on to mauve. It will still be called a bloom, because nature is apparently the only designer allowed to submit a colour palette without a stakeholder meeting, a brand workshop or a director demanding more blue.
Real story: NASA Earth Observatory.
