Mussel farmers in northern France are facing a crisis due to an increase in spider crab population, which has led to the decimation of their crops in the gulf between Brittany and Normandy. The explosion in crab numbers over the past decade threatens the future of the mussel industry, leading to significant financial losses and calls for government assistance. The French Research Institute for Exploitation of the Sea (Ifremer) is studying the crabs to develop strategies to mitigate their impact, but in the meantime, mussel farmers are permitted to catch and release the crabs to reduce their numbers near mussel concessions. However, farmers are advocating for spider crabs in their farming areas to be classified as pests, allowing for more aggressive control measures.