Blue lobsters: scientists question rarity as sightings rise

Blue lobsters have long been touted as one of nature’s wonders, widely cited as a one-in-two-million find. But scientists and hatchery staff say the creatures may not be as rare as once thought, with more frequent sightings and a growing interest in understanding what drives the vivid color.

The blue hue in lobsters results from a complex interaction between two compounds. Astaxanthin is a red pigment lobsters absorb from their diet, while crustacyanin is a protein that binds with astaxanthin to produce a blue tint. In most lobsters, this combination yields a dark, muddy blue-green shell that helps them blend into the seabed. When the balance shifts—due to genetics or environmental factors—the color can become dramatically more vibrant. Scientists describe blue lobsters as having a genetic mutation that causes an overproduction of crustacyanin, giving them their electric appearance.

Experts have also noted that environment appears to play a role. Chris Weston, senior hatchery technician at the National Lobster Hatchery in Padstow, Cornwall, has observed color changes in lobsters raised in captivity. He said some hatchery-born lobsters hatch and grow up with an electric blue look, but when they are moved to containerized sea pens, they often shift to a darker, more natural blue. When returned to the hatchery, they become lighter again. Weston suspects factors such as light exposure and diet may influence pigmentation—hatcheries can be brighter than the seabed, and captives may have less access to astaxanthin-rich food, allowing crustacyanin to dominate. Similar environmental changes could be occurring in the wild, potentially contributing to more blue-lobster sightings.

Are blue lobsters still rare? Scientists say there appears to be an uptick in sightings. Prof Jamie Stevens of the University of Exeter said the reports have become more frequent, though he cautioned that his own sample size is not large. “There’s been an uptick in sightings,” he said. “We haven’t seen a huge rise in our own samples, but fishermen are reporting more of them.” If the mutation is being passed on and the individuals are surviving and reproducing, the trait could become more common over time. Ben Marshall, head of production at the hatchery, said the results may indicate the color is less rare than previously thought: “It seems they may not be as rare as we thought. It was thought that blue lobsters are as rare as one in two million, but with the average catch in Cornwall of roughly half a million individual lobsters landed each year, we should only see one blue lobster every two years.”

The broader question remains whether the perceived rise in blue-lobster sightings signals a genuine shift in population or simply greater familiarity and reporting. Experts say it is too early to draw firm conclusions. PA Media and BBC News have highlighted that historical assumptions tied bright color to vulnerability to predators, especially during moulting. Stevens noted that there is no clear link between the blue coloration and climate-change-related factors in the crustacyanin genes, which are controlled by two genetic loci. “The crustacyanin, the blue colour, is under the control of two genes and we don’t see any relationship with those genes and anything that might constitute a trend towards changes in climate,” he said.

Researchers stress that more systematic study is needed to determine whether numbers are rising and, if so, why. They advocate genetic analyses, environmental monitoring, and collaborations with fishermen to build a clearer picture of blue-lobster dynamics. Beshlie Pool of the South Devon and Channel Shellfishermen said a recording scheme would be useful, noting that the last confirmed catch of a blue lobster in south Devon waters occurred about a year ago. More data will help scientists separate genuine trends from sporadic sightings and better understand the ecological and evolutionary factors behind this striking color.

In the meantime, researchers emphasize caution in interpreting short-term observations. While the electric blue hue continues to captivate the public, the practical implications for fisheries management and conservation remain uncertain. Scientists plan to pursue genetic studies and long-term monitoring to determine whether blue lobsters are truly becoming more common, and what that might mean for lobsters in the wild and in hatcheries.