Purple Shore Crabs: A Fascinating Coastal Treasure
Gorgeous Purple Crabs Color Beaches from Alaska to Mexico
Adult Purple shore crab at Baynes Sound, British Columbia, Canada
The Pacific Coastline of North America is full of surprises. One of these is the incredible coloration of many of the beach inhabitants and deep water marine life alike. While colorful birds fill coastal forests and surprise first time viewers, equally brilliant sea creatures make many Pacific tidepools resemble a tropical aquarium.
Actual purple crabs are a colorful and sometimes unexpected find that actually represent one of the more common marine crustaceans along the coast. Enter the Purple shore crab Hemigrapsus nudus in the marine beauty contest! Yes, it is just a small crab but it has shell coloration that rivals a piece of Amethyst quartz crystal. Living in water less than four feet in depth, Purple shore crabs gain protection from rocky environments, which they greatly favor over more open sandy or muddy shorelines. Rather than engaging in elaborate burrowing adventures, these agile and rugged small crabs will scuttle under rocks and make forays out to scavenge and prey on small marine creatures. Their powerful claws are large in proportion to their body, but the actual creature is far too small to be dangerous to humans.
Caution and a penchant for sticking close to rocks is well advised, for Purple shore crabs are just the right size for countless shorebirds, ducks, gulls and even beach visiting landbirds like crows and blackbirds to pick off. Who wouldn't want crab dinner? Though too small to be of typical interest to humans for food, these creatures are a source of entertainment to beachcombers.
To promote conservation of this important link in the marine food web, avoid littering and support green & effective coastal planning and waste management efforts that retain native vegetation and mitigation of marine pollution. A planted buffer in between beaches and developed areas can reduce greatly detrimental runoff of chemicals and particulate pollution.