NASA captures a ring of colour in the Pacific near the Chatham Islands

Blooming seas were recorded around the Chatham Islands in January 2026, after satellite images showed large swirls of colour spreading across the Pacific Ocean. The remote island group lies far east of New Zealand’s South Island and is rarely noticed beyond marine charts and weather maps. That changed when bright green and blue patterns appeared in surrounding waters, visible from space. The colours were linked to a seasonal surge of phytoplankton, microscopic organisms that drift near the ocean surface. NASA instruments captured the event as it unfolded, revealing a wide ring encircling the islands. While such blooms are not unusual in this region, the scale and clarity drew attention to ocean processes that usually remain out of sight.The bloom was observed by the Visible Infrared Imaging Radiometer Suite aboard the NOAA 20 satellite. Data processed through NASA Earth Observatory showed delicate spirals and looping bands around the islands on January 10. The colour came from chlorophyll within phytoplankton, which reflects light in ways satellites can detect. When currents pull these organisms into dense patches, the ocean surface shifts from dark blue to vivid green. This year’s patterns appeared more defined than usual, shaped by surface eddies moving slowly across the rise.The islands sit on the Chatham Rise, a broad underwater plateau stretching east from New Zealand. The seafloor here is shallower than the surrounding waters, influencing how currents move and mix. Cold nutrient-rich flows from the Southern Ocean meet warmer subtropical water along this boundary. The mixing does not happen evenly. Pockets of nutrients rise, then drift, creating conditions where phytoplankton can multiply quickly. Long summer daylight adds another factor, giving these organisms more time for photosynthesis.Phytoplankton blooms occur most summers in this part of the Pacific. They tend to form along the rise rather than directly around the islands themselves. Scientists tracking ocean colour have seen similar events over many years. What stood out in 2026 was the clear ring-like shape and the way currents traced it into thin strands. The bloom did not suggest a sudden change. Instead, it reflected a strong expression of processes already known to operate here.The growth of phytoplankton feeds directly into the wider marine food web. Small organisms consume them, followed by fish and larger predators. Waters around the Chatham Islands support valuable fisheries, including pāua, rock lobster and blue cod. These species rely on steady productivity rather than brief surges. The rise has long been considered one of New Zealand’s more productive offshore regions, partly because nutrients are renewed by circulating currents.The same conditions that support fisheries also attract marine mammals. At least five seal species live in the region, alongside around 25 species of whales and dolphins. Many pass through during feeding migrations. Sightings are common, though the area remains lightly populated by people. The abundance can appear concentrated at times, with animals drawn into overlapping paths shaped by food availability and underwater features.Despite the richness of life, the Chatham Islands are also known for frequent whale and dolphin strandings. Some events have involved hundreds of animals. Researchers have not settled on a single cause. Theories range from complex seafloor acoustics to navigation challenges created by shallow gradients. Blooms themselves are not considered direct triggers, but the same ocean structure that drives productivity may also influence how animals move through the area.NASA continues to monitor the region using satellite instruments linked to the Joint Polar Satellite System. These tools allow scientists to track seasonal changes without relying on ships or long field campaigns. The images offer patterns rather than conclusions. They show movement, colour and scale, leaving interpretation open. For the Chatham Islands, the bloom was a brief moment of visibility, then a return to relative quiet as currents shifted and colours faded.