The impacts of purple marsh crabs on salt marshes can be viewed from space. The crabs leave expansive, fan-shaped mudflats as they burrow into the marsh and consume large swaths of cordgrass.

Bertness says the marshes are being overrun by purple marsh crabs because their main predators, blue crab and finfish, are being overfished. So, the purple marsh crabs are free to gorge on healthy ...

Millions of purple marsh crabs are churning through salt marshes along the East Coast, significantly disrupting the storage of carbon within these ecosystems. The small crabs' constant burrowing ...